Sistema Universitario Ana G. Méndez Universidad del Turabo · 2018. 4. 26. · Sistema...

Sistema Universitario Ana G. Méndez

Universidad del Turabo

52st ACS Junior Technical Meeting

37th Puerto Rico Interdisciplinary Scientific Meeting

ABSTRACTS

BOOK

April 28/2018

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52nd ACS Junior Technical Meeting 37th Puerto Rico Interdisciplinary Scientific Meeting

(PRISM)

Sistema Universitario Ana G. Méndez Universidad del Turabo

Gurabo, Puerto Rico

April 28/2018

SPONSORED BY

American Chemical Society – Puerto Rico Section Puerto Rico Louis Stokes Alliance for Minority Participation Resource Center for Science and Engineering, University of Puerto Rico Central Administration Sistema Universitario Ana G. Mendez, Universidad del Turabo

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52nd ACS Junior Technical Meeting

37th Puerto Rico Interdisciplinary Scientific Meeting (PRISM)

Sistema Universitario Ana G. Méndez Universidad del Turabo

April 28/2018

Table of Contents ORAL PRESENTATIONS .................................................................................................................................. 4

Agricultural Sciences ........................................................................................................................ 5

Astronomy........................................................................................................................................ 7

Chemistry ....................................................................................................................................... 11

Computer Science ........................................................................................................................ 105

Electronics .................................................................................................................................... 128

Engineering .................................................................................................................................. 133

Environmental Science ................................................................................................................. 185

General Sciences .......................................................................................................................... 241

Geosciences ................................................................................................................................. 252

Life/Biological Sciences ................................................................................................................ 267

Mathematics ................................................................................................................................ 429

Pharmaceutical Sciences .............................................................................................................. 443

Physics .......................................................................................................................................... 447

POSTER PRESENTATIONS .......................................................................................................................... 467

Agricultural Sciences .................................................................................................................... 468

Chemistry ..................................................................................................................................... 470

Engineering .................................................................................................................................. 497

Environmental Science ................................................................................................................. 509

Geosciences ................................................................................................................................. 522

Industrial Pharmacy ..................................................................................................................... 528

Life/Biological Sciences ................................................................................................................ 530

Mathematics ................................................................................................................................ 554

Physics .......................................................................................................................................... 558

Pharmaceutical Sciences .............................................................................................................. 564

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ORAL PRESENTATIONS

Agricultural Sciences

Astronomy

Chemistry

Computer Science

Electronics

Engineering

Environmental Science

Geosciences

Life/Biological Sciences

Mathematics

Pharmaceutical Sciences

Physics

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Room: ECT 230 Time: 12:00-12:20 PM

Presenter: Zheidyleen Massó Rodríguez Mentor: Rosado-Martinez, Abeliz

Title: Study of the Vascular Flora of the La Olimpia Forest Reserve

Authors: Abeliz Rosado-martinez (PCUPR), Zheidyleen Massó Rodríguez (PCUPR)

Abstract

Forest areas in Puerto Rico have increased during the past 60 to 70 years. Many of these forests are

spontaneous forests that have emerged after the abandonment of agriculture or animal husbandry.

Although there are publications about their recovery, little is known about the patterns and recovery

processes of these forests. This research focuses on succession processes after the abandonment of

agricultural land. The "Bosque Escuela La Olimpia", which comprises some 60 acres, is located in the

central mountainous area in the Saltillo neighborhood in Adjuntas. The elevation ranges are between

300 and 1,000 meters above sea level. The study was conducted in quadrants of 400m2, which were

selected randomly and without replacement based on the altitudinal ranges. In each quadrant, all trees

with a diameter at breast height (DBH) of at least 5 cm were sampled. The trees were identified by

species and according to their status: native, naturalized, endemic, rare or in danger of extinction. We

consider the lower slopes as highly disturbed areas and the high slopes as areas of mature vegetation.

The low areas of the mountains are composed mainly of herbaceous plants, such as herbs, vines and

ferns, but there are also some cultivated species such as citrus, legumes and passion plants. Of the tree

species so far sampled, a total of 24 species have been identified. Of these, 10 species are naturalized,

11 species are native and 3 species are endemic. The information of the flora and data obtained in this

research allows us, and will allow the scientific community to better understand the processes of

ecological succession in secondary forests, in addition to serving as a basis to create models of forest

recovery in Puerto Rico.

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Astronomy

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Astronomy

Room: ECT 230 Time: 12:20PM-12:40PM

Presenter: Rosemary Cortés Robles Mentor: Lebron, Mayra

Title: Preliminary Results on the Arecibo Pisces-Perseus Supercluster Survey

Authors: Rosemary Cortes (University of Puerto Rico - Rio Piedras Campus), Mayra Lebron

(University of Puerto Rico - Rio Piedras Campus), Michael Jones (Instituto de Astrofisica

de Andalucia, Granada, Spain), Rebecca Koopmann (Union College, Schenectady, NY,

United State), Martha Haynes (Cornell University, Ithaca, NY, United State), Appss Team;

Undergraduate Alfalfa Team; Alfalfa Team

Abstract

The Arecibo Pisces-Perseus Supercluster Survey (APPSS) aims to exploit the Baryonic Tully-Fisher

Relation to derive distances and peculiar velocities of galaxies in and near the main ridge of the Pisces-

Perseus Supercluster (PPS), one of the most prominent features of the Cosmic Web in the nearby

Universe. The sample of galaxies contains ~ 600 sources in the low-mass range (8 6. With this sample,

the nature of the galaxy population in and around the PPS will be investigated. The HIMF to log MHI ~

8.0 along the PPS filament will be measured and using the Tully-Fisher relation it will be possible to

make a robust measurement of the infall and backflow onto the filamentary structure.

APPSS is collaborative project between more than 10 Undergraduate ALFALFA Team institutions in

which each group contributes to the analysis of a subset of the HI PPS data. In this poster, we will

present the contributions of the U.P.R. team to the APPSS project. We will show the procedure used for

the Arecibo HI data analysis, including some examples, and will show our preliminary

results.

This work has been supported by NSF grants AST-1211005, AST-1637339 and AST-1637276.

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Astronomy


Presenter: Byron Morales Maldonado Mentor: Cotto Figueroa, Desiree

Title: Report on the Observation of Binaries in 2013: Humacao University Observatory

Authors: D. Cotto (UPR-H), R.j. Muller (UPR-H), J.c. Cersosimo (UPR-H), R. Rodriguez (UPR-H), M.

Diaz (UPR-H), M. Rosario (UPR-H)

Abstract

This is a report on observations of position angle and separation of binary stars of the year 2013 from

the Humacao University Observatory. The stars analyzed totaled 62; they were imaged at the NURO 31

inch telescope in Flagstaff, Arizona in June 2013. The images were analyzed at the Humacao Observatory

of the University of Puerto Rico.

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Astronomy


Presenters: Marjory Reyes Méndez Néstor O Márquez Ríos Mentor: Cotto Figueroa, Desiree

Title: Separation and position angle measurement of binary star systems taken from

Washington Double Star Catalog

Authors: Rafael Muller (Universidad de Puerto Rico en Humacao), Desiree Coto (Universidad de

Puerto Rico en Humacao), Nestor Marquez (Universidad de Puerto Rico en Humacao),

Marjory Reyes-mendez (Universidad de Puerto Rico en Humacao), Byron Morales

(Universidad de Puerto Rico en Humacao), Orlando Carromero (Universidad de Puerto

Rico en Humacao)

Abstract

We report on measurements of position angle and separation of a group of binary pairs. The data was

obtained using the NURO Telescope at Anderson Mesa location of Lowell Observatory, 20 miles east of

Flagstaff, Arizona in 2014. We gathered the data using 2K x 2K CCD camera, -NASACAM- at the prime

focus of the 31 imch telescope. The data was transfered and analized at the University of Puerto Rico at

Humacao Observatory by undergraduate students undertaking research projects.

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Chemistry

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Chemistry


Presenter: Andrea N. Marcano Delgado Mentor: Fasoli, Ezio

Title: Development of a fluorescent assay for benzaldehyde detection

Authors: Andrea Marcano-delgado, Ezio Fasoli

Abstract

Benzaldehyde is wide range used as an industrial solvent, flavoring material in food, intermediary in

organic reactions to produce perfumes, and in the organic synthesis as precursor of a plethora of

compounds. In pharmaceutical industry, benzaldehyde is a toxic oxidation product of benzyl alcohol, a

co-solvent used as a preservative in injectable formulations such as Na-diclofenac, Voltaren, vitamin-B

complex and non-steroidal anti-inflammatory drugs. Benzaldehyde as a potential impurity can cause

neurotoxic effects in patients, especially in infants. Having a sensitive analytical method to detect low

concentrations of benzaldehyde is necessary and useful in biomedical and pharmaceutical applications.

Our research group is interested in the development of a simple, fast, sensitive and precise fluorescence

assay for the detection of benzaldehyde at nanomolar concentrations. The main goal is to optimize the

reaction conditions of the synthesis of the fluorescent probe. In the reaction, benzamidine and glyoxal

react forming an intermediary, 2-phenyl-4,5-dihydroxy-2-imidazolone. The intermediary reacts with the

benzaldehyde forming the final fluorophore, 2-aryl-4-arylidene-2-imidazolin-5-one. The yellow

fluorophore formed was characterized by NMR, UV-VIS and fluorescence spectroscopy. The limit of

detection was 49 nM, and the limit of quantification was 163 nM. Our work extends to continue

exploring the best experimental conditions to detect the analyte at lower nanomolar concentrations and

in this way offer a better approach in aldehydes detection.

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Chemistry


Presenter: Joel Rivera Cardona Mentor: Rivera, Joel

Title: Effects of Additives on the Prebiotic Formation of Depsipeptide Oligomers.

Authors: Joel Rivera Cardona (University of Puerto Rico at Mayaguez), Kathyria Toro Arevalo

(University of Puerto Rico at Mayaguez), Aikomari Guzman Martinez (University of

Puerto Rico at Mayaguez)

Abstract

To this day, the process by which the first peptides were formed with the conditions present in the

prebiotic Earth are unknown. Scientists have proposed some hypotheses that state that polyester

polymers are the ancestors of polypeptides. Furthermore, there has been evidence that links

depsipeptide oligomers as an intermediate of this process. Depsipeptide oligomers can be formed using

conditions that simulates prebiotic environments. The monomer used in this work was (2-

Hydroxyacetyl) Alanine (gA), which was dried down with different Magnesium II salts to evaluate the

formation of the depsipeptide oligomers. As a result, the better additive was Magnesium Sulfate

(MgSO4), because it had the cleanest reaction, having less byproducts of amide and ester hydrolysis.

Nevertheless, the addition of other inorganic salts such as Magnesium Chloride (MgCl2) developed a

negative effect in the formation of the depsipeptide oligomers. The data obtained demonstrates that

the formation of depsipeptide oligomers can be affected negatively or positively by the presence of

inorganic salts.

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Chemistry


Presenter: Natalia C. Badillo Vélez Mentor: Rivera Portalatin, Nilka M.

Title: ROS Scavenging ability, bioactivity and composition analysis of Hylocerus undatus

(Pitahaya) fruit

Authors: Nilka M Rivera Portalatin (UPR-MAYAGUEZ), José F Robles Rivera (UPR-MAYAGUEZ),

Natalia C Badillo Vélez (UPR-MAYAGUEZ)

Abstract

Reactive oxygen species are one of the most important type of radicals in biological system due to its

toxicity at higher levels. Pitahaya (Hylocerus undatus), commonly known as dragon fruit, is a specie of

Cactaceae and dwells in tropical and subtropical regions. White-flesh Pitahaya, a plant regarded as a

medicinal plant, was evaluated in terms of its antioxidant and possible bioactivity. In order to assess the

antioxidant capacity, in vitro 1,1- diphenyl-2-picryl hydrazyl (DPPH) radical scavenging assay was

performed. Cytotoxic activity was assessed by the Artemia salina (Brine shrimp) lethality bioassay.

Positive results were observed as far as antioxidant and bioactivity at low extract concentration. Extract

composition analysis was carried out using Gas-chromatography/Mass-spectrometry (GC-MS). The

compounds identified were compared with extracts obtained from other plants to further understand

the obtained activity. This study suggests a promising foundation for investigating and understanding

the beneficial effects of Hylocerus undatus as natural source of antioxidants and, since a strong

correlation between bioactivity in the brine shrimp lethality bioassay and anti-cancer activity has been

established, the compounds extracted in this research could be promising as preventive agents against

carcinogenic cells in humans.

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Chemistry


Presenters: Valeria C. Torres Irizarry Nicole L. Márquez Reyes Mentor: Bansal, Vibha

Title: Optimizing auto-induction of tissue-type plasminogen activator in E.coli.

Authors: Valeria C. Torres Irizarry (University of Puerto Rico at Cayey), Vibha Bansal (University of

Puerto Rico at Cayey), Saurabh Chattopadhyay (Lerner Research Institute)

Abstract

Thromboembolic disorders, the leading cause of disease-related mortality in USA, were reported to be

responsible for approximately 614,348 deaths in 2015. Medicinal intervention for these disorders is

available in the form of Plasminogen Activators (PAs), enzymes that are capable of dissolving blood clots

(thrombus) by restoring the blood flow through the affected body part. We have been involved with

engineering tissue-type Plasminogen Activator (tPA), a thrombolytic protease that is considered the

most effective agent to treat thrombovascular diseases due to its higher fibrin specificity and lower side

effects. Several mutants have been designed in our laboratory, and expressed in SHuffle® E. coli strains

These E.coli strains, available commercially (New England Biolabs), have been genetically modified to

allow the expression of complex proteins rich in disulfide bonds. We used three different SHuffle strains:

i) SHuffle® Express Competent E. coli (C3026H); ii) SHuffle® T7 Express Competent E. coli (C3029H); and

iii) SHuffle® T7 Express lysY Competent E. coli (C3030H). The expression of tPA variants was induced

using the method of auto-induction. This is the first ever application of auto induction method to

expression of tPA. A thorough optimization of induction/expression conditions was thus needed. We

carried out an optimization of lysis conditions followed by time and temperature profiles for obtaining

significantly high expression of the tPA variants. At least two SHuffle strains allowed for expression of

enzymatically active tPA variants without the presence of protease inhibitors by virtue of the inherent

potential of the strains used to prevent protease expression. Time temperature profiles revealed a

significant impact of tested conditions on the tPA variants' yields.

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Chemistry


Presenters: Ambar N. Pagan Garcia Kaleb E. Negrón Torres Mentor: Alape, Fabio

Title: Conceptual Design of a Biodiesel Portable plant for Waste Vegetable oil in Puerto Rico.

Authors: Dr. Fabio Alape Benitez (University of Puerto Rico in Humacao), Ambar Pagan Garcia,

Kaleb Negron Torres

Abstract

Nowadays, almost all the combustion machines use fossil fuels or their derivatives. They generate

emissions of Volatile Organic Compounds (VOC's), Particulate Matter (PM), NO compounds – NOx– and

Greenhouse gases (GHG) such as carbon monoxide – CO- and carbon dioxide – CO2 -, which contribute

to the global warming one of the big driving force of the climate change. Today, there are many things

people can do to save Earth and reduce global warming. So what can people do to save Earth? Well

that's when biodiesel comes to the rescue. But what is biodiesel? Biodiesel is a renewable synthetic

biofuel obtained from different kinds of triglycerides such as: vegetable oils or animals fats. Using this oil

as fuel can bring to the environment a lot of benefits. According to the Energy Department of the United

States, this biofuel can reduce the emissions of CO until a 50%, PM a 50%, although an increase of 10%

could be obtained in the NOx emissions. Another important benefit of the Biodiesel is the reduction of

more than a 75% of CO2 compared with the traditional diesel fuel when an analysis of Life Cycle – LCA -

is used. In terms of energy, biodiesel yields 4.56 units of energy for every unit of fossil energy consumed

over its lifecycle. 1 Approximately four millions of gallons of waste vegetable oil (WVO) are recycled in

Puerto Rico every year and almost other two millions of gallons are not processed, this analysis indicates

that a Biodiesel Portable Plant using this waste vegetable oil could be useful both for recycling and as a

fuel renewable source. Using this oil as fuel can bring to environment a lot of benefits. The present study

has a principal purpose to make biodiesel at Laboratory Scale, obtaining the principal parameters

required in the design of a new Portable Plant by deployment of the Super Pro Designer process

simulator.

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Chemistry


Presenter: Ileanexis M. Madera Cuevas Mentor: Pares-Matos, Elsie I.

Title: Expression of 6xHis tagged FAP1(short) and its Isolated using Ni-NTA Chromatography

Authors: Ileanexis Madera Cuevas

Abstract

Fpr1p is an immunophilins that help to mediate the correct folding of proteins. Fpr1p forms complex

with immunosuppressant drugs such as rapamycin. The Fpr1p-rapamycin complex inhibits the functions

of TOR1 and TOR2 gene products in the cell cycle progression. In absence of rapamycin, Fpr1p interact

physically with other proteins such as calcineurin, biosynthetic enzyme aspartokinase, high mobility

group (HMG) and FAP1. FAP1 competes with rapamycin for the binding site of Fpr1p. FAP1 is a

cytoplasmic protein in Saccharomyces cerevisiae but few known about this, for this reason we study it.

The main objective of this project is express and isolation of FAP1 (short) for studying its function and

interaction with other proteins in yeast. The fap 1 gene was inserted in an expression vector pET21a-LIC,

cloned and expressed BL-21C43(DE3)pLysS+ and KRX, strains of Escherichia coli. Our purpose is inserting

an oligonucleotides sequences of 6xHis and Factor XA in pET21a-Lic:FAP1 to purification mediated Ni-

NTA Agarose Chromatography.

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Chemistry


Presenter: Jesús M. Santiago Borges Mentor: Parés-Matos, Elsie I.

Title: Characterization and Purification of rPDGFB from Crude Lysates using GST-Affinity

Chromatography

Authors: Jesús M. Santiago-borges (University of Puerto Rico - Mayaguez), Elsie I. Parés-matos

(University of Puerto Rico - Mayaguez)

Abstract

Platelet-Derived Growth Factors (PDGFs) are molecules that induce development in embryonic stages,

and regulate negatively and positively vertebrate cell cycle, by controlling cell migration, growth and

differentiation. Moreover, PDGF has been related to cancer, arteriosclerosis and several proliferative

disorders. During its discovery, isolating PDGF was not an easy task due to its low concentration in initial

samples, but it was necessary for the characterization of its structure and functionality. Due to its

dimeric structure, several isoforms have been found biologically active, ranging from 27 to 31 kDa, and

with hydrophobic and cationic properties. The production and subsequent purification steps required

for isolated biomolecules include complex and expensive procedures. Thus, our main purpose is to

express rPDGB from E. coli strain BL21 C43 (DE3) pLysS, and purify it from bacterial crude lysate using

GST-Affinity Chromatography.

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Chemistry


Presenter: Graciela B. Raffucci Colomer Mentor: Rivera Portalat, Nilka M.

Title: GC/MS, brine shrimp lethality assay and DPPH scavenging ability studies of the

methanolic extract of Aloe vera

Authors: Graciela B. Raffucci Colomer (UPR Mayaguez), Jose F. Robles (UPR Mayaguez), Dra. Nilka

M. Rivera Portalatin (UPR Mayaguez)

Abstract

Reactive oxygen species are free radicals, which is an oxygen atom in an unstable molecule that reacts

with other molecules violently. Aloe vera (L.) Burm. f. is originally from the Arabian Peninsula but can

grow in tropical climates. It is also known for its medicinal properties and it has been proven that the gel

within this plant provides a large array of healing properties. Antioxidant activity of methanolic extract

was analyzed using the DPPH free radical scavenging assay and the bioactivity was measured using the

brine shrimp lethality assay. Positive results were obtained from the assays performed at low

concentrations, revealing high percentage of bioactivity. Compounds within the extracts were identified

through the Gas Chromatography/Mass Spectrometry technique. The reported activity of the identified

compounds was reviewed to further understand the extract bioactivity and antioxidant capacity. The

extract composition was compared to different metabolites identified in other plants utilized for similar

purposes.

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Chemistry


Presenters: Adriana N. Santiago Ruiz Edgardo J Sánchez Rivas Mentor: Bansal, Vibha

Title: Effects of Ligand Density on Protein Binding Capacity of Affinity Membranes

Authors: Adriana N. Santiago Ruiz (University of Puerto Rico at Cayey), Edgardo J. Sánchez Rivas

(University of Puerto Rico at Cayey), Vibha Bansal (University of Puerto Rico at Cayey)

Abstract

Ligand Density is an important determinant of the protein binding capacity and selectivity of protein

separation devices. The relationship between ligand density and the protein binding capacity is also

affected by the size of the target protein. The goal of this project is to understand these relationships. To

accomplish this, commercially available cellulose acetate membranes of a pore size of 3.0 microns were

chemically modified with para-mino benzamidine (pABA) and tested for protein binding. Preliminary

studies showed a successful capture of the protein from a pure protein solution using these affinity

membranes. As a second step, cellulose acetate membranes of various ligand densities were modified

similarly. An accurate quantification of pABA is needed to evaluate the protein binding capacity of the

membranes. Glyoxal method based on the formation of a fluorescent derivative of para-

aminobenzamidine was thus adapted and optimized for amidine quantification in solid phase on

membrane surface. With this method, the ligand (amidine) concentrations on membranes of 3.0 micron

pore size were determined to be in the range of 0.1-0.00056 nmoles amidine per mL of membrane.

Protein binding experiments using fluorescently labeled Subtilisin Carlsberg showed a linear increase in

protein binding by the membrane with increasing ligand density upto X. Any further increase in ligand

density did not promote more protein binding.

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Chemistry


Presenter: Luis A. Acevedo Soto Mentor: De Jesus, Walleska

Title: Radical scavenging, antioxidant activity, phenolic content, and trypsin inhibition assays

from the leaves of Alpinia zerumbet

Authors: Luis A. Acevedo Soto (University of Puerto Rico at Aguadilla), Walleska De Jésus-bonilla,

Phd (University of Puerto Rico at Aguadilla)

Abstract

Free radical production and lipid peroxidation are involved in the pathogenesis of some chronic

diseases. That is why there has been an increase in research on phenolic compounds in plants. Also,

enzyme inhibition has become an important aspect in pharmaceutics because of their potential in

treating diverse diseases. Plant derived proteases have been shown to not only help plants in defense

against pathogens but as well as having potential to be used as part of a pharmaceutical agent. Previous

research has shown the presence of proteins, phenols, and flavonoids present in the leaves of Alpinia

zerumbet. To further characterize the proteins identified, we conducted protease inhibition assays using

trypsin in hopes of identifying proteins that are proteases. This assay revealed activity against trypsin,

showing approximately 60% activity inhibition. Next, the leaves were investigated for free radical

scavenging activity, antioxidant activities, and total flavonoid content. Radical scavenging activity using

DPPH showed no significant activity at a concentration of 2mg/mL, however, adding the pure extract to

the DDPH solution showed a 40.4 % inhibition activity against the DDPH radicals. For the ABTS radical

scavenging assay, a total antioxidant activity of 54.95% was measured. Flavonoid content was measured

using the colorimetric method of AlCl 3 in terms of quercetin equivalents (mgQE/g). Total flavonoid

content was found to be 3.04 mgQE/g. Further studies will include optimization of the DDPH radical

scavenging assay as well as extraction and purification of the proteins in the leaves of A. zerumbet.

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Chemistry


Presenter: Junellie L. Cruz Lebrón Mentor: Fasoli, Ezio

Title: In situ analysis and protein binding on affinity membranes at varying ligand density.

Authors: Junellie L. Cruz Lebrón (University of Puerto Rico-Humacao), Sean Yeldell (University of

Pennsylvania), Jose Sotero (University of Puerto Rico-Humacao), Ivan Dmoschowski

(University of Pennsylvania), Ezio Fasoli (University of Puerto Rico-Humacao)

Abstract

Affinity membrane purification is an advantageous technique which allows separation of proteins

through binding between an affinity ligand linked to a membrane and the target molecules. The

quantitative analysis of the ligand density and protein binding using a laser scanning confocal

microscope (LSCM), were pursued in this research. LSCM is an instrument of choice for imaging solid

phases with a fluorescent probe.

Affinity cellulose membranes were synthetized as follows: Cellulose acetate membranes with a pore size

of 3 µm (Sterlitech) were deacetylated in basic conditions, reacted with the 5 atom spacer arm,

epichlorohydrine and further functionalized with para-aminobenzamidine (pABA), an affinity ligand for

serine proteases in the cellulose acetate membranes.

I order to visualize the membranes structure and porosity under LSCM, the chemically modified

membranes were dyed with a fluorescent probe Rhodamine B (ex. 545 nm, em. 580 nm). The PABA

affinity ligands were reacted with glyoxal and Fluorene-2-carboxaldehyde leading to a fluorescent probe

with exmax 488 nm and emmax 530 nm. Finally the serine protease Substilisin carlsberg from Bacillus

licheniformis, was fluorescently labeled with Fluorescein isothiocyanate (ex. 480 em. 520 nm) and used

as model protein to study protein binding on chemically modified affinity membranes.

Different images of membrane carrying different ligand density, and protein concentration were taken

using the LSCM. Analysis of images was done using an algorithm which allows through pixel counting to

determine: the degree of membrane functionalized with the affinity ligand and the amount of protein

bound to the ligand.

23

Chemistry


Presenter: Nathalie González Cuevas Mentor: Nieto Ramos, Santander

Title: Improved Electrochemical Performance of Olivine LiFePO4 Cathode Materials for

Lithium Ion Batteries.

Authors: Nathalie González (Universidad del Turabo), Santander Nieto Ramos (Universidad del

Turabo)

Abstract

Lithium-ion batteries are emerging as a major power sources for portables appliances such as prime

candidate for hybrid electric vehicles (HEVS), plug-in hybrid electric vehicles (PHEVs) and electric

vehicles (EVs) for reasons of high energy density, high power density, better cycleability and safety. For

the application in high power devices (various consumer electronic products such as laptop, camcorder,

etc.) the discharge capacity of Li ion batteries at higher current rate required is to be improved. As

diffusion of lithium ions inside the active material particles is the rate-limiting step of intercalation

process, faster Li+ diffusion in the electrode materials could improve the rate capabilities of Li ion

batteries. Olive LiFePO4 is a very promising cathode material used in lithium ion batteries, due to its

environmental friendliness, high theoretical capacity (170 mAhg-1), low cost of precursors, high

reversibility of Li+ insertion/extraction, good thermal stability, and lack of toxicity. In spite of these

attractive features, LiFePO4 requires further modifications to overcome limitations such as poor

electronic conductivity and slow lithium ion diffusion. In this work we have synthesized olivine LiFe1-

xMxPO4 (M = Nb, Yb, Sb)(LFMPO) powders by co-precipitation method. The synthesized powders were

used to prepare cathodes for Li ion coin cells. The structural and electrochemical properties were

investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform

infrared, Raman spectroscopy, cyclic voltammetry and charge-discharge studies, respectively. The phase

pure and crystalline quality of the materials was studied from XRD peaks and their line widths

respectively. The cyclic voltammetry of both the cathodes revealed the reversible nature of Li-ion

intercalation in the cell. The dopant induced structural and stoichiometric modifications were correlated

with the voltage cycling and charge discharge characteristics of these cathode materials.

24

Chemistry


Presenter: Ann M. González Piñeiro Mentor: Reyes, Elba

Title: Effect of an in vitro human digestion on the major cannabinoids present in commercially

available cannabis oils

Authors: Ann Marie González Piñeiro (University of Puerto Rico at Cayey)

Abstract

Cannabis is a plant that belongs to the Cannabaceae family from which different types of cannabinoids

are being isolated. The most recognized components are tetrahydrocannabinol (THC) and cannabidiol

(CBD) due to their effects on the human body, which can be used for recreational (the psychoactive

effect of THC) and medicinal (therapeutic effect of CBD) purposes. The focus of this study is the

qualitative analysis of the chemical changes in the components of commercially available cannabis oils

after being subjected to simulated stages of the human digestive process, specifically the oils distributed

by Sinaí and Go Life which are claimed to be 100% organic, dietary supplements, enriched with CBD and

registered by the FDA. The oils were analyzed by Chromatographic (GC and TLC) and spectroscopic (GC-

MS, 1HNMR, and 13CNMR) techniques to establish the control parameters prior to their submission to

an in vitro human digestion process, namely the stages involving the mouth, stomach and small

intestine, respectively. The mixture recovered after each stage was subjected to a liquid-liquid

extraction process using solvents of different polarities- such as hexane, ethyl acetate and

dichloromethane- and the changes in the oils' components were identified by a comparative study with

the control parameters.

25

Chemistry


Presenter: Kevin J. Negrón Rosado Mentor: Bailon Ruiz, Sonia

Title: Evaluation of the Toxicity of Cadmium Sulfide Quantum Dots modified with L-

Glutathione on Aquatic Systems

Authors: Kevin J. Negron-rosado (University of Puerto Rico in Ponce), Sonia Bailon-ruiz (University

of Puerto Rico in Ponce)

Abstract

Quantum Dots have played a significant role in the resurgence of new technologies. They have excellent

optical properties and are being used in a great number of applications in materials science and in the

biomedical fields. Mass production in factories liberate these nanoparticles into the atmosphere

affecting the soil, the air and, bodies of water. As semiconductors they are toxic but, by surface

modification methods, we can create a barrier between the ion releasing core and the environment,

reducing or even eliminating their toxicity. In this experiment, our objective was to evaluate the toxicity

of Cadmium Sulfide (CdS) Quantum Dots modified with L-Glutathione acting as surface protectant in our

model organism Artemia Salina. Also, ionic cadmium (as Cd2+) was used as comparison purpose. Our

synthesized CdS Quantum Dots were generated by Microwave irradiation technology in presence of

thioglycolic acid (TGA) and further functionalized with Glutaraldehyde, and finally modified with a

biocompatible compound like L-Glutathione. Our surface modification was confirmed utilizing infrared

studies, photoluminescence and UV-Vis spectra. After experimentation we found a higher percentage of

viable Artemia Salina in toxicity assays of CdS Quantum dots in comparison to assays of Cd2+, which

released ions freely onto the solution. Several concentrations were used for evaluation. For Cd2+ (as

cadmium sulfate), we used concentrations of 0 ppm, 10 ppm, 50 ppm, 100 ppm, 300 ppm, 500 ppm, 700

ppm and 1000 ppm. Greater concentrations showed a higher rate of mortality for our Biological

organisms. Anova tests for these results were positive, therefore we can conclude that there was a

significant difference in survival rate of our Artemia Salina regarding concentration. We proceeded with

t-Tests for Cadmium Sulfate between 0 ppm and 500 ppm, 0 ppm and 700 ppm, and, 0 ppm and 1000

ppm, portraying a significant difference percentage in comparison to the control group. Both ANOVA

and t-tests showed negative results for our L-glutathione covered Quantum Dots. Therefore, we

concluded that the surface functionalization method with organic ligands is effective to overcome this

nanoparticle's toxicity. CdS nanoparticles containing L-Glutathione as protectant ligand proved to

contain the minimum toxic capacity and to be more biocompatible with living organisms.

26

Chemistry


Presenter: Gabriel Cruz Ruiz Mentor: Portalatin, Nilka

Title: Phytochemical analysis of Spermacoce remota Lam., in search of understanding its

phytochemical and ethno-pharmaceutical properties

Authors: Lolita Rodriguez1\ (UPRM), Odalis Ramirez (UPRM), Bryan Padua (UPRM), Bryan Medina

(UPRM), Gabriel Cruz (UPRM)

Abstract

Spermacoce remota Lam., commonly known as "Juana la Blanca", is a medicinal plant native to Puerto

Rico, folklorically used to treat kidney stones. Preliminary works in our lab show that S.remota Lam. is an

excellent phytoremediator for TNT (2,4,6-trinitrotoluene) and cadmium ions. The goal of this project is

to correlate the chemical composition of Juana la Blanca with its medicinal and phytoremediation

properties. To do this, plant material was collected from the field and properly identified by a botanist

as Spermacoce remota Lam. Leaves, flowers and stems were collected, sterilized, freeze-dried, milled,

and frozen for preservation. To study its chemical composition Soxhlet extractions were done in

dichloromethane (DCM) and hexane and analyzed by GC-MS. On the other hand, aqueous extracts of

Juana were submitted to qualitative tests for secondary metabolites to confirm the presence of tannins

and saponins, giving positive results. We hypothesize that these compounds may be the active

ingredients responsible for the ethno-pharmaceutical and phytoremediation properties of this plant.

These aqueous extracts were also used for cadmium and calcium ions fluorescence quenching

experiments to elucidate it capability to complex these ions. We will present our preliminary results

identifying potential secondary metabolites responsible for Juana activity. We will also present

fluorescence quenching evidence of Juana capability to complex Cd+2 and Ca+2 ions.

27

Chemistry


Presenter: Chalier Dones Ortiz Mentor: Rivera-Portalatín, Nilka M.

Title: Chemical composition, bioactivity and antioxidant capacity of the methanolic extract of

Curcuma longa L. (Turmeric)

Authors: Chalier Dones Ortiz (UPR, Mayaguez), José Robles (UPR, Mayaguez), Nilka M. Rivera

Portalatín (UPR, Mayaguez)

Abstract

Turmeric (Curcuma longa L.) is widely known for it's use as a medicinal agent and a spice or condiment

in the diet of different countries. Previous researches have demonstrated that Turmeric has formidable

antioxidant capacity. Reactive oxygen species are very unstable and, as a consequence of their

reactivity, they can react easily with other molecules. They are known to be one of the sparks of cancer

and a wide range of conditions. Some of the medicinal properties of Turmeric could be from the

antioxidant capacity it has. The objective of this research was to make a screening of the possible

secondary metabolites responsible of the antioxidant action of Turmeric and the determination of the

bioactivity of such compounds using the brine shrimp assay. The methanolic extract was analyzed using

GC/MS and 16 compounds were identified with significant abundance. The antioxidant capacity of the

extract was assessed by the DPPH assay and the bioactivity was measured with the brine shrimp

lethality bioassay. Future work is intent on studying compounds found in the extract individually. In turn,

this will help immensely to better understand turmeric's capacity as a useful antioxidant and its capacity

to eliminate reactive oxygen species. Subsequently, this work may show major applications towards

natural remedy guidelines implemented in distinct types of degenerative diseases.

28

Chemistry


Presenter: Adaliz J. Torres Rosado Mentor: Fasoli, Ezio

Title: Fluorescence based assay for quantitative analysis of benzamidine in solid phase

Authors: Adaliz Torres (Dept. of Chemistry at University of Puerto Rico at Humacao), Christian

Ortiz (Dept. of Chemistry at University of Puerto Rico at Humacao), Adriana Santiago

(Dept. of Chemistry at University of Puerto Rico at Cayey), Vibha Bansal (Dept. of

Chemistry at University of Puerto Rico at Cayey), Ezio Fasoli (Dept. of Chemistry at

University of Puerto Rico at Humacao)

Abstract

The purification of therapeutic proteins from complex mixtures such as cell culture broth is a challenging

and expensive task due to the long time required and the high costs of chromatography purification

systems. Among the different purification techniques affinity separation allows the binding of the target

molecules on the matrix with high affinity and selectivity. The ligand distribution over the matrix plays

an important role for the optimization of the process. The objective of this work is the development of a

solid phase fluorescent assay for the determination of ligand density in solid phase. In order to achieve

this goal cellulose acetate membrane were deacetylated and reacted with epichlorohydrin leading to

the introduction of a 5-atoms long spacer arm (linker) on the membranes. The spacer arm epoxide

groups were further functionalized with para-aminobenzamidine (pABA), an affinity ligand selective for

serine proteases. The amount of pABA attached to the membranes was estimated via a fluorescent

assay in which the amidine moiety is reacted with glyoxal and benzaldehyde leading to the fluorescent

probe 2-aryl-4-arylidene-2-imidazolin-5–one (ex. max. 385nm em. max. 538 nm). A standard curve was

obtained submerging unmodified cellulose membranes in solutions containing increasing concentration

of the fluorescent probe and show a linearity in the 1-5 mM range. The curve was used to measure the

ligand density of pABA on the chemically modified membranes. The method was also tested with

commercially available pABA purification matrix (Benzamidine-Sepharose® from GE Healthcare Life

Science) and gave ligand density values in accordance with the manufacturer specification. The

substitution of benzaldehyde with other aromatic aldehydes lead to new related fluorescent probes. In

this article we show how the method can be used also for imaging membranes and ligand distribution

with Laser confocal microscope.

29

Chemistry


Presenter: Shakira M. Escobar Avilés Mentor: Ramos-Santana, Brenda J.

Title: Design extraction techniques of the hemolymph in invertebrate species from Puerto

Rico

Authors: Shakira Marie Escobar-aviles (University of Puerto Rico - Aguadilla), Brenda J. Ramos-

santana (University of Puerto Rico - Aguadilla)

Abstract

Extraction is a very broad technique that may have many different functions. Some of the most

commonly used extraction techniques are analytical and organic extractions, which generate quality

information. Procedures involving this technique may serve to isolate compounds in different phases,

for example organic and aqueous phase, which facilitate the analysis and identification of compounds

present in the samples collected. The main research goal is to design techniques to extract the

hemolymph in invertebrate species from Puerto Rico. To develop this research, it is necessary to hunt

the invertebrate and analyze them in the laboratory. Some extraction techniques that will be used to

achieve our goal are single-drop microextraction and liquid-liquid extraction. The expected result is

design an effective and efficient methodology to extract hemolymph from invertebrate species so it can

be analyzed and characterized in further studies.

30

Chemistry


Presenters: Gerardo Caminero Rivera Natalie M Pantoja Rodriguez Mentor: Pena, Guido

Title: Biodiesel Production

Authors: Gerardo Caminero Rivera (University of Puerto Rico at Arecibo), Natalie Pantoja

Rodriguez (University of Puerto Rico at Arecibo), Kimberly Valderrama Sanchez

(University of Puerto Rico at Arecibo), Jamillez Olmo Classen (University of Puerto Rico

at Arecibo), Wilnoshka S. Medina Torres (University of Puerto Rico at Arecibo)

Abstract

The purpose of this research is to demonstrate that the Biodiesel (BD) can be produced from new and

used vegetable oil, without relying on fossil fuel. The objectives are develop a process for BD production

from new and used vegetable oil, determine viscosity (with two methods: Stocks and Oswald

viscometer), density and average yield (?) for each one, and develop a process to produce soap from the

glycerin. BD is a synthetic biofuel obtained from natural lipids such as vegetable oil. BD was prepared by

transesterification reaction using vegetable oil and the sodium methoxide mixture in an agitator reactor,

maintaining the temperature at 48°C for a period of 50 minutes. Then it was subjected to various

washing steps with distilled water to remove any impurities, and by operation of decantation, the BD

was separated from the glycerin. The glycerin was a secondary product to produce soap, as a method of

recuperation. The ? for the new vegetable oil was 70% while for the used vegetable oil was 77%. The

average viscosity for the new vegetable oil was 5.46g/cm-s and for used vegetable oil was 16.61g/cm-s.

In addition, we measure the viscosity with the Oswald viscometer and the results are very close to the

Stokes method (the average from new oil was 6.99cSt and from used oil was 21.13cSt) this indicates that

it is within range of the industrial BD. The average density of biodiesel from new vegetable oil was

0.90g/ml and the used vegetable oil was 0.77g/ml. The BD produced was tested in a Ford 250 pickup

truck and digger owned by the University of Puerto Rico Arecibo Campus, both with an excellent

performance.

31

Chemistry


Presenter: María T. Morales Colón Mentor: Reyes, Elba

Title: Can the lyophilized extract from Maguey roots brew be used as a dietary supplement?

Authors: Maria T. Morales Colon (University of Puerto Rico at Cayey), Elba D. Reyes (University of

Puerto Rico at Cayey)

Abstract

Agave americana, commonly known as Maguey, is a plant that has been used as a natural treatment for

diabetes type II. Different species of Agave have revealed the presence of saponins, flavonoids, and

polyphenols, which are the potential compounds responsible for its therapeutic effects. Furthermore,

components such as saponins can be hydrolyzed into compounds like sugars, phenols, and steroidal

aglycones in acidic conditions, such as in the gastric juices. Most investigations have analyzed the

components of the leaves of the plant; however, in Puerto Rico, people have claimed to experience

therapeutic effects from consuming the brew of the roots. Preliminary studies of derivatized extracts

from Maguey roots have revealed anticancer properties, the presence of iron, polyphenolic compounds,

and PARABEN (an antifungal compound). Hence, the objective of this investigation is to analyze the

changes in the organic components extracted in a lyophilized fraction (equivalent to a dietary

supplement dose) of the Maguey roots brew once they are submitted to an in vitro digestion process.

The in vitro digestion process simulates the steps of digestion upon the passage of the lyophilized

extracts through the mouth and stomach. The aqueous solutions obtained after each digestion step

were extracted with ethyl acetate and dichloromethane and the dried extracts collected after each step

were analyzed by chromatographic techniques, such as TLC and GC. In addition to the chromatographic

analyses, a comparative study of the iron percentage and phenolic contents contained in the extracts

after the in vitro digestion steps with the one reported in previous investigations will be presented.

These results will be used to propose the use of the lyophilized extract from Maguey roots as a dietary

supplement.

32

Chemistry


Presenter: Jerika R. Rivera Martínez Mentor: Bailon Ruiz, Sonia

Title: Evaluation of Gold Nanoparticles Toxicity in Artemia Salina

Authors: Jerika Rivera (University of Puerto Rico in Ponce), Sonia Bailon Ruiz (University of Puerto

Rico in Ponce)

Abstract

Gold nanoparticles (Au NPs) are particles that varies in shapes and size with a ranging diameter of 10 nm

to 100 nm. Shape and size depend on the way the NPs are synthesized. Au NPs have characteristic

optical properties that help them distinguish between other nanomaterials; the phenomenon called

Surface Plasmon Resonance (LSPR) is due to a strong absorption in specific wavelengths or frequency of

light. The intrinsic optical properties of gold nanoparticles make them suitable for different applications

such as photocatalysis, optical sensors, drug delivery, among others. The objectives of this study were

synthesize and characterize Au NPs of different sizes and evaluate their toxicity in Brine shrimps. The

reduction of gold ions (Au3+) to Au0 in the presence of the reducing agent sodium citrate was

accomplished in aqueous phase. As a result, spherical particles with two sizes were obtained. The

resulting gold nanoparticles were characterized using fourier transform infrared spectroscopy (FT-IR),

high resolution transmission electron microscopy (HRTEM) and UV-Visible Spectrophotometry. Au NPs

(two sizes) evidenced surface plasmon peaks at 524 nm and 534 nm, respectively. Larval stage (nauplii)

Artemia Salina were exposed for periods of exposure of 24 hours and 48 hours to different treatments

of ionic gold, sodium citrate, and Au NPs. Organisms contacted with sodium citrate at different

concentrations showed no toxicity after 24 hour and 48 hours of exposure. As the concentration

increased and time passed viability decreased for toxicity test of Au3+ on all organisms. Hence, ionic

gold is toxic for these organisms compared to gold nanoparticles. Au NPs evidenced toxicity at

concentrations higher than 100 ppm, causing a complete lethality in A. Salina. Furthermore,

fluorescence microscopy was used to study the ingestion of Au NPs into the gastrointestinal tract of

Artemia Salina.

33

Chemistry


Presenter: Rocío i. Zorrilla Veloz Mentor: Lopez-Mejias, Vilmali

Title: Polymer-induced Heteronucleation and Solubility of a Cancer Therapeutic Agent

Authors: Rocio I Zorrilla-veloz (University of Puerto Rico- Rio Piedras Campus), Torsten Stelzer

(University of Puerto Rico- Medical Campus 0), Vilmali Lopez-mejias (University of

Puerto Rico- Rio Piedras Campus)

Abstract

Many therapeutic agents display polymorphism, the ability of a substance to exist as two or more

crystalline phases that differ in their arrangements of the molecules within the crystal lattice. This study

encompasses the polymorphic screening of 5-fluorouracil (5-FU) a widely used chemotherapeutic agent

to treat solid tumors, that include colorectal, head and neck, breast, and lung cancer. 5-FU is a

dimorphic system; hence physicochemical properties such as stability, dissolution rate, and solubility are

expected to differ. The latter two properties are of paramount importance for the pharmaceutical

industry because they impact the bioavailability of the therapeutic agent. At the moment 5-FU is

commercialized in the most thermodynamic stable form, form I. In this work, 2D polymer surfaces are

employed as heteronucleants to promote access to additional polymorphs of 5-FU and gain insights into

the heteronucleation kinetics of this system. To initiate these efforts, the solubility of the model

compound has been measured in various solvents, primarily, Class III solvents at temperatures ranging

from 278.15 K to 333.15 K using the polythermal method. The experimental solubility data of 5-FU in the

pure solvents and solvent mixtures were correlated using the modified Apelblat and λh model

equations. The predicted solubility data obtained agree with the experimental data based on the

calculated relative deviation (RD%) and the average relative deviation (ARD%) values. Based on the

solubility curves, ethanol was chosen as the solvent to crystallize 5-FU. Four diverse cross-linked

polymer libraries were designed and employed as heteronucleants during the crystallization of 5-FU

from ethanol through evaporation. Various solid-state characterization techniques such as polarized

optical microscopy, Raman spectroscopy, thermal analysis, powder and single X-ray diffraction have

been used to determine the resulting polymorph in 26 different crystallizations of 5-FU. Optical

microscopy revealed morphological differences on the crystals grown, and Raman spectroscopy

confirmed the crystals presented different vibrational modes when compared to the commercial form,

5-FU form I. Selected crystals were further characterized with micro-powder X-ray diffraction which

revealed these crystals were the 5-FU form II. Currently, the reported method of obtaining 5-FU form II

is through evaporative crystallization of a saturated solution of the compound in dried nitromethane at

room temperature. The explosive properties nitromethane and the extensive time (three months) for

the crystallization, make the present method not viable in pharmaceutical applications wishing to

manufacture this form. Further analysis of the 5-FU form II crystals, will be conducted to gain

mechanistic understanding of the possible polymer-drug interactions leading to this polymorphic form in

this simple and straightforward approach.

34

Chemistry


Presenters: Paola M. Colón De León Andrea C Gonzalez Vazquez Mentor: Garcia, Carmelo

Title: Molecular Modeling of 1-Benzazepine Analogues that bind to the Ach Protein (2PH9)

Using Autodock

Authors: Paola M. Colon, Andrea C Gonzalez, Carmelo Garcia, Margarita Ortiz-marciales

Abstract

Ligand interactions of the Benzazepines analogs with the neuronal nAChRs are being studied to see

which analogue of BNZP fit into the binding site of an ACh-binding protein (AChBP). The 1-benzazepine

analogues enhance the positive allosteric modulation of the receptor of nicotinic acetylcholine ?-7

(nAChR). The heat of formation of the benzazepine analogues was calculated at the quantum levels of

PM3 Hyperchem. The analogues were preoptimized using MM + and the semi-empirical method PM3

with the Polak-Ribière conjugate gradient (RMS 0.01 Å-1 kcal / mol). The protein-ligand binding of these

benzazepine analogs to AChBP is being determined using the AutoDockTools1.5.6 and AutoDock Vina

coupling programs in which the affinity of all analogs can be calculated. The best ranked derivatives

contain 7,8-methoxy groups and a polar 1-substituent. The command prompt also plays an important

role in the docking of each BNZ.

35

Chemistry


Presenter: Jesús F. Rodríguez Rodríguez Mentor: Bailon Ruiz, Sonia

Title: Ligand Exchange Method to Functionalize Semiconductors CdSe Quantum Dots and the

Evaluation of their Toxicity

Authors: Jesus Rodriguez Rodriguez (University of Puerto Rico in Ponce), Sonia Bailon Ruiz

(University of Puerto Rico in Ponce)

Abstract

Semiconductors Quantum Dots (QDots) have specific optical properties depending on its structure and

size. Also, these nanostructures can be easily functionalized using organic compounds when they are

produced directly in aqueous phase. QDots can be produced by several methods but the microwave

technique is a recommended tool to synthesize water-stable nanocrystals. The microwave-assisted

procedure has the capacity of inducing the interaction of the dipole-dipole moment of the molecules,

avoiding temperature gradients and consequently increasing the synthesis rate; also it is a low cost and

eco-friendly technique. The high production of nanoparticles (like QDots) because of their numerous

applications, generates a huge amount of waste that can be harmful to the ecosystem reaching the

water bodies, the soil, even the air. Therefore, it is important to study and evaluate the toxicity of these

nanostructures in aquatic systems. The objectives of this research were: i) characterize CdSe QDots by

spectroscopies techniques, ii) modify the surface of QDots using organic compounds and iii) evaluate the

impact of CdSe QDots on aquatic organisms. QDots were synthesized and functionalized using L-

glutathione or cysteine. The functionalization protocol consisted in removing the original organic cover

(thioglycolic acid or TGA) of QDots and replaces it initially with glutaraldehyde and, subsequently with L-

glutathione or L-cysteine. The integrity of the QDots's optical properties was verified by

Photoluminescence Spectroscopy. In this way, QDots covered with TGA, glutaraldehyde, glutathione and

cysteine evidenced high emission peaks at 552 nm, 553 nm, 549 nm and 556 nm, respectively. Artemia

salina was used as model to evaluate the toxicity of functionalized nanoparticles. Also, Cd2+ as cadmium

chloride and cadmium acetate was used in toxicity studies using A. Salina. Results showed that Cd2+

from ionic compounds were toxic to A. Salina, increasing the mortality significantly (t-student at 95%

confidence level) at concentrations higher than 300 ppm after 24 hours and 48 hours of exposure. This

observation can be attributed to the generation of reactive oxygen species (ROS) by cadmium ionic.

QDots with TGA cover showed no toxicity to aquatic organisms, whereas the presence of glutathione or

cysteine on the QDots surface caused a slightly increase in mortality. The ingestion of QDots by A. salina

was corroborated using a Fluorescence Microscopy. The presence of green fluorescence in all specimen

analyzed indicated the uptake of QDs by the aquatic organisms and the preservation of the QDots

integrity into the organisms.

36

Chemistry


Presenters: Jocelyn M. Jiménez Cruz Nerylis Ruiz Fontán Mentor: Pena, Guido

Title: Bacterial Inhibition with Extracts from Algae Padina Gymnospora

Authors: Nerylis Ruiz Fontán, Jocelyn M. Jiménez Cruz

Abstract

Since last, seaweeds were used as food and for their healing like medicine. The purpose of this research

is to determine whether the Marine Brown Algae Padina gymnospora inhibit bacterial growth. These

algaes have a fan-like shape with 2 or 3 cm of diameter. The algal samples were collected over reef area

at 1.0 to 1.5 meters of depth in Punta Papayo La Parguera in Lajas, Puerto Rico. These were settled to

the lab with sea water and ice. Then, we proceed to washed it with fresh water to remove any salt or

other particle before the extraction. To complete the extraction process was necessary the use of

organic solvents such as chloroform and methanol in a 2:1 proportion. During the procedure of rotary

evaporation, the solvents were separated of the liposoluble extracts from Padina. To test and compare

the antibacterial activity of the extract, was required the use of commercial antibiotics. This was

executed using the disk diffusion assay. The bacterial stock was classified as Gram (+) or Gram (-). The

latter one was consisted of Escherichia coli and Pseudomona aeruginosa. In change, in the Gram (+)

group were Staphylococcus aureus and Bacillus cereus. The results demonstrated that the inhibition

varies according the type of bacteria used. Thus, the data of the standard deviation have shown that the

inhibitory zone diameter corresponding to the algal ex-tract have been way more effective compared to

a commercial antibiotic like penicillin. For instance, Pseudomonas aeruginosa had a deviation of 14.8 ±

1.76 mm in comparison to penicillin which had a deviation of 2 ± 5.06 mm. Moreover, there is a seasonal

influence in Padina gymnospora, from which we concluded that the inhibitory activity is related with the

algal reproductory cycle.

37

Chemistry


Presenter: Kenneth Fontánez Mora Mentor: Machin De Jesus, Abniel

Title: Photo-degradation of Ciprofloxacin using titanium gold-based catalysts

Authors: Kenneth Fontánez (Universidad del Turabo), Abniel Machín De Jesús (Universidad del

Turabo), Francisco Márquez Linares (Universidad del Turabo), Carmen Moran

(Universidad autonoma de madrid), Loraine Soto-vázquez (Material Characterization

Center), Edgar Resto (Material Characterization Center)

Abstract

Antibiotics have eased the life of many since their development, fighting off diseases along with

countless infections on a day to day basis. Thanks to it, life expectancy have increased significantly ever

since. But as our bodies secretes these antibiotics after they had made their functions, one way or

another these antibiotics end up in waste waters leading to rivers and coasts. These antibiotics by-pass

standard government sanitation systems used to develop potable water. This in turns lead to the

antibiotic spreading out to domestic pipelines reaching our homes. At this point, the possibilities of

consuming water contaminated with antibiotics increases greatly. A constant exposure to antibiotics

make the body develop immunity to its effects. In turn, this allows for a better chance for an infection to

be successful since the antibiotics will not have full effect on the host. To address this issue, we focus on

the photo-degradation of these contaminants using advance oxidation processes. The antibiotic this

research focus on is Ciprofloxacin, which is used to treat a variety of infections. The objective of this

investigation if to photodegrade Ciprofloxacin using a gold-based titanium catalyst in the shortest time

possible. Usually between 1 to 3 hours.

The process involves introducing our catalyst (TiO2 nano wires) in a recipient containing a

solution of ciprofloxacin in which was radiated with UV light to degrade it. The catalyst is activated when

radiated by UV light and begins the process of oxidizing the contaminant further. The parameters

considered in this study included the effect of concentration of the antibiotic, the initial pH of the

solution, the amount of catalyst (1%Au@TiO2 NWs), and the irradiation time. The optimum degradation

(86%) was obtain at a pH of 6, a concentration of 3.5 x 10-4 M Ciprofloxacin, a catalyst concentration of

1 g/L and an irradiation time of 3 hours. The catalyst showed good potential to degrade the contaminant

in a reasonable amount of time. As a future research, degradation experiments will be conducted with

higher amount of gold nanoparticles incorporated to the catalyst.

38

Chemistry


Presenter: Daisy Y. Díaz Rohena Mentor: Montes, Ingrid

Title: Effect of Counterions on the Biological Activity of Ferrocenyl Chalcone Salt Derivatives

Authors: Díaz-rohena, Daisy (UPR-RP), Delgado-rivera, Sara M (UPR-RP), Montes-gonzález, Ingrid

(UPR-RP)

Abstract

Ferrocenyl chalcones have exhibited a wide range of biological activity. This important framework has

been synthesized introducing different substituents or derivatives that have also demonstrated

biological activity: anti-plasmodial, anti-cancer, and antibacterial, among others. An important limitation

is that most of these chalcones are insoluble in water. Solubility of active compounds in aqueous media

determines their absorption, bioavailability, and pharmacokinetic profile, and if they can be orally

administered as drugs. Due to this, it is important to increase their solubility, for their possible use as

orally administered drugs and a more accessible treatment for diseases. Recently, our laboratory

reported the synthesis and electrochemical properties of new ammonium and pyridinium ferrocenyl

chalcone salt derivatives with alkylsulfate as the counterion, which improve their solubility in aqueous

media. To further this interest, two possible lipophilic chains in the nitrogen of the amine or pyridine

substituent of the ferrocenyl chalcones structures were incorporated. Some of the salts showed good

potential as antioxidants, and others inhibited the growth of cervix and hormone-independent breast

cancer. This research is focused on the evaluation of the effect of counterions on the solubility and

biological activity of these salts. To achieve our specific aim, salts of halides, oxalate, and malate are

being prepared by ion exchange chromatography. Synthetic methodology, further characterization, and

bio assays regarding radical scavenging, of these compounds will be elaborated.

39

Chemistry


Presenter: Joenisse M. Rosado Rosa Mentor: Rosado, Joenisse

Title: Developing learning and teaching method using SciLab modeling for Physical Chemistry

Authors: Joenisse M Rosado (Universidad del Sagrado Corazón), Paloma Opio (Universidad del

Sagrado Corazón), Rolando Guzmán-blas (Universidad del Sagrado Corazón)

Abstract

The teaching and learning of Physical chemistry are developed theoretically and experimentally,

sometimes when the student needs to graph or perform some solutions of differential equations

presents some difficulties. A good tool of aid are software or computer programs but are of difficult

economic access. We propose Scilab as an auxiliary tool to solve computational problems in the course

of physical chemistry, which will reinforce student learning. Scilab is free and open source software for

numerical computation providing a powerful computing environment for engineering and scientific

applications. We present some examples applied as a particle in a box, motion in two and more

dimensions, vibrational motion.

40

Chemistry


Presenter: Dixie N. Bracero Cordero Mentor: Alamo Nole, Luis

Title: Photodegradation of Victoria Blue with CdSSe Quantum Dots

Authors: Dixie N. Bracero-cordero (Pontifical Catholic University of Puerto Rico)

Abstract

Quantum dots (QDs) are metal-based nanoparticles that have sizes from 1 to 10 nanometers. QDs have

been used in different areas such as biomedical, optical, and electronics. They are colloidal

semiconductor nanocrystals that have the capacity to absorb light and emit photons at specific

wavelengths. In this research, the capacity of QDs to produce reactive oxygen species (ROS) during the

emission process are been used to degrade Victoria Blue (VB). VB is an organic dye used in textile

industries and they can reach public waters affecting the environment and humans. The capacity of QDs

to be excited with low energy and produce ROS should promote photodegradation reactions that help

to degrade the VB. Photocatalysis is a more beneficial technique because generates less toxic products

than other methods like oxidation and reduction process, electrocoagulation, or incineration process. VB

water samples mixed with CdSSe QDs were irradiated at 302nm for specific periods and the residual dye

concentration was quantified by High Performance Liquid Chromatography (HPLC) with a Variable

Wavelength Detector (VWD).

41

Chemistry


Presenter: Alondra A. Rivera Raíces Mentor: López-Mejías, Vilmalí

Title: Revealing Novel Bisphosphonate-based Coordination Complexes to Treat Bone Related

Diseases

Authors: Alondra A. Rivera Raíces (UPR-RIO PIEDRAS), Waldemar A. Rodriguez (UPR-RIO

PIEDRAS), Vilmalí López-mejías, Phd (UPR-RIO PIEDRAS)

Abstract

Bisphosphonates (BPs) have resonated as the leading treatment for bone-related diseases do to their

strong affinity for hydroxyapatite in bone and inhibition of bone resorption. In spite of their successful

therapeutic outcomes, these drugs have been attributed to serious side effects such as esophagitis,

digestive problems, and low levels of calcium. This investigation proposes the use of biocompatible and

clinically relevant BPs as organic ligands, which in coordination with bioactive metal ions, such as

calcium (Ca2+), will result in the development of phosphonate-based biocompatible coordination

complexes (pBioCC's). These structures could present an alternative to currently employed BPs

formulations, which could potentially reduce the above-mentioned side effects caused by the

deprotonation of hydroxyl groups in physiological pH by means of the coordination bonds. Moreover,

this research presents a challenge from a crystal engineering perspective due to the propensity of

phosphonates to form amorphous powders, hampering the structural elucidation of these materials.

Here, we report on the synthesis of a pBioCCs composed of etidronic acid (HEDP) and Ca2+ ions, and

named HEDP-Ca. Hydrothermal synthesis of this compound was carried out with a M2+/BP molar ratio

of 1:1 and a temperature of 85°C. Evaporative crystallization was employed in order to successfully

improve the morphology of the initial crystals. Raman spectroscopy, thermogravimetric analysis (TGA),

powder and single crystal X-ray diffraction (PXRD and SCXRD) and scanning electron microscopy with

energy dispersive spectroscopy (SEM-EDS) were employed as solid-state characterization methods to

provide evidence of the composition, structural and thermal behavior of this material. Energy Dispersive

Spectra evidenced the presence of elements from both ligand and metal ion (carbon, phosphorous,

oxygen and calcium). While comparison of the PXRD to that of a previously synthesized HEDP-Ca (form I)

indicated that the produced material was in fact unique; hence, it was termed HEDP-Ca form II. TGA

attributed a 10% weight loss to the ligand and a 6% weight loss to the metal. TGA showed that the new

complex is less thermally stable than previous synthesized form, HEDP-Ca form I, and that both

complexes are less stable than the ligand, HEDP. Moreover, auxiliary additives, including alendronic acid

(ALEN), risedronic Acid (RISE), were combined with HEDP and calcium ion in an attempt to improve the

crystallization outcomes. This hydrothermal synthesis resulted in a new structure, ALEN-RISE-HEDP as

evidenced by PXRD. Further characterization will be required in order to elucidate the structure of this

material. Future studies will involve the evaluation of the dissolution profiles these and other pBioCCs in

various physiological media and their cytotoxicity through in vitro studies involving various cell lines.

42

Chemistry


Presenters: Vitmary Rivera Rodríguez Paola Nahid Carrion Colon Mentor: Cunci, Lisandro

Title: Synthesis and Characterization of a Fluorescent and Biocompatible: Graphene Oxide

Quantum Dots

Authors: Joed E. Ortiz Santiago (Universidad del Turabo), Vitmary Rivera Rodriguez (Universidad

del Turabo), Paola N. Carrion Colon (Universidad del Turabo), Reynaldo De Jesus

Carrasquillo (Universidad del Turabo), Lisandro Cunci (Universidad del Turabo)

Abstract

The detection of cancer has been one of the primary points of examination in the most recent years

because of the necessity of more rapid and sensitive techniques to provide fast and accurate results.

Research is our best defense against cancer. Graphene Oxide Quantum Dots (GOQD) have extraordinary

properties such as the emission of fluorescence. The most attractive property of GOQDs is the fact that

they are made of carbon, a material that is highly abundant and cost effective while at the same time

showing low toxicity in biological applications. This project will focus specifically on the synthesis and

characterization of biocompatible carbon material GOQD. To prove that the sample did emit

fluorescence we used an UV Lam (302nm), and to messuer it was used a microplate reader. The sample

was excited using wavelengths between 350 nm and 790 nm. To prove the completion of the synthesis

we used Raman, to confirm the structure and purity we used X-ray Diffraction, and to measure the

particles size in the sample we used Anatomic Force Microscopy. Toxicity studies shows how can GOQD

can emit fluorescence without harming the cell . This will allow us to use light to excite the quantum

dots, and measure the fluorescence as a way to detect cancer.

43

Chemistry


Presenter: Nerika G. Hernández Santiago Mentor: Cunci, Lisandro

Title: Electrochemical Detection of NPY using Modified Aptamer Platinum Microelectrodes

Authors: Nerika G. Hernandez Santiago (Turabo University), Luis F. Lopez (Turabo University),

Lisandro Cunci (Turabo University)

Abstract

Neuropeptides are small molecules responsible for communication among cells in the central nervous

system and peripheral nervous systems. NPY is a highly evolutionary conserved peptide involved in

stress response and mediation, appetite stimulation and plays a role in pathological conditions like

obesity, anxiety and neurogenerative diseases. The mechanism for the process involve in the stress

regulation has not yet been defined. The purpose of this project is to use Electrochemical Impedance

Spectroscopy for the detection of NPY at different concentrations and frequencies to have another

method that provides a better understanding for the mechanism of the peptide. Also, serve as a

baseline of future studies of different neuropeptides and neurotransmitters. Our results show detection

in each concentration at different frequencies between 5MHz to 10Hz. Modified aptamer platinum

microelectrodes allow us to understand NPY concentrations at the electrode surface. Electrochemical

Impedance Spectroscopy will be developing to understand the mechanism and the detection of

neuropeptides at real time in future studies.

44

Chemistry


Presenters: Keila M. De León Alcázar Belmarí Méndez Santiago Mentor: Ospina, Claudia

Title: Study of Chemical Ccomposition, Cytotoxic and Antitumor Activities of Croton Discolor

Authors: Keila Marí De León Alcázar (UPR Cayey), Belmarí Méndez Santiago (UPR Cayey), Claudia

Andrea Ospina (Universidad del Turabo), Pablo E. Vivas Mejía (UPR Ciencias Médicas)

Abstract

Croton discolor, commonly known as "lechecillo", is a plant that belongs to the family of Euphorbiaceae.

This native plant can be found in tropical systems such as in Puerto Rico. In previous studies, this plant

has shown a growth inhibition (> 84%) against two cancer cell lines, MCF-7 and T47D (1). Likewise, two

aporphine alkaloids have been isolated from this plant, characterized by an amine group and a group of

carbon rings.

Based on the cancer growth inhibition studies, we decided to isolate and identify the chemical

compounds in the cortex of Croton discolor responsible for this biological activity. The plant was

collected, dried and extracted with a mixture of CH2Cl2-MeOH (1:1). The resulting crude extract was

suspended in water and extracted with solvents of different polarities. These extracts were analyzed by

proton nuclear magnetic resonance (H-NMR) and cytotoxic activity against breast (MCDF-7, ZR-75-1,

T47D and MDA-MB-231), ovarian (A2780CP20) and prostate (PC-3 and LNCAP) cancer cell lines. The

preliminary data shows, that ethyl acetate and chloroform extracts are the most promising to isolate the

compounds of interest.

45

Chemistry


Presenter: Melissa Velázquez Rodríguez Mentor: Alamo Nole, Luis

Title: Toxicity of CdSTe in Caenorhabditis Elegans

Authors:

Abstract

Caenorhabditis elegans have been widely studied in the field of science, especially in medicine. They

have been used to study nervous system, Alzheimer's disease, diabetes, obesity and premature aging.

These nematodes measure approximately 1 mm in length. They live in temperate environments and eat

microorganisms (E. coli). Each hermaphrodite adult can produce from two hundred to three hundred

eggs. The average lifetime of an adult in the laboratory at room temperature (20-25 C) is from two to

three weeks. The goal of this research is evaluate the toxicity of CdSTe nanoparticles in C. Elegans.

Nanoparticles measure less than 100 nanometers and there are four types of nanoparticles: carbon

nanoparticles, metal, dendrimers, and composites. The metal nanoparticles can be quantum dots made

of gold, silver, titanium, among others. Quantum dots (QDs) are semiconductor particles with optical

and electrical properties. The capacity of the QDs to emit photons (fluorescence) after an excitation step

will be used to observe their incorporation inside C. elegans by fluorescence microscopy. The small size

and the capacity of the QDs to produce reactive oxygen species could produce toxicity and dead of the

nematodes.

46

Chemistry


Presenter: Crystal A. O'Neill Arroyo Mentor: Griebenow, Kai

Title: Biodiesel synthesis with nano-particulate lipase formulations from various lipid sources

Authors: Crystal A. O'neill (Department of Chemistry, University of Puerto Rico, Rio Piedras

Campus), Rohit K. Sharma (Department of Environmental Sciences, University of Puerto

Rico, Rio Piedras Campus), Hector A. Rivera (Department of Environmental Sciences,

University of Puerto Rico, Rio Piedras Campus, P.O. Box 23346, San Juan, Puerto Rico

00931), Bibek Thapa (Department of Physics, University of Puerto Rico, Rio Piedras

Campus), Vanessa B. Bovea (Department of Chemistry, University of Puerto Rico, Rio

Piedras Campus), Kai Griebenow (Department of Chemistry, University of Puerto Rico,

Rio Piedras Campus)

Abstract

One of the major challenges for the sustainable fatty acid methyl or ethyl ester (FAME/EE, a.k.a

biodiesel) production is the smart utilization of low-cost feedstocks, e.g., waste cooking oil (WCO),

brown grease, or algal lipids. Although traditional catalyst systems could be used to transform such

feedstocks into biodiesel, some well-established drawbacks are associated with their use. Alternatively,

lipases can convert the FFA-rich feedstocks into FAME/EE in a manner with less environmental impact.

However, low enzyme activity in organic solvents and high cost remain challenging for the industrial

application of lipase nanoparticles. In this study, we are addressing these drawbacks of lipase by

developing lipase nanoparticles (LNP), cross-linked lipase nanoparticles (CLNP), and immobilized LNP on

iron oxide nanoparticles (IONP).

Lipase from Candida rugosa was selected as an economic widely available source and purified to ca.

>90%. Different formulations of nanoparticles were formed, and detailed surface and morphological

characterizations were performed by using the various microscopy techniques, e.g., scanning and

transmission electron microscopy, and atomic force microscopy, dynamic-light-scattering, and magnetic

properties by the vibrating-sample magnetometer. For structural characterization, Fourier-transform

infrared spectroscopy and X-ray diffraction were used. Identification of fatty acid esters was done by gas

chromatography coupled to a mass spectrometer. The activity of the LNP, CLNP, and LNP-IONP

formulations increased 10-, 20-, and 32-fold in n-hexane, 18-, 42-, and 54-fold in 1,4 dioxane, and 13-,

29-and 43-fold in THF, respectively, compared to lyophilized lipase. Detailed analysis of fatty acid ester

formation was performed using the different combinations of substrates (WCO, microalgae lipids, brown

grease, methanol and ethanol), lipase formulations (lyophilized lipase, LNP, CLNP, and LNP-IONP), and

solvent systems (hexane, 1,4 dioxane, THF, and t-butanol). The nanoparticulate lipase formulations

converted high percentage lipids into fatty acid esters in less time and the overall operational stability of

the system improved considerably.

47

Chemistry


Presenter: Stephannie M. Rosario Garrido Mentor: Rosario, Stephannie

Title: The reaction of sulfhydration in cysteine and cystine

Authors: Stephannie Rosario Garrido (University of Puerto Rico at Cayey), Ruth Pietri (University

of Puerto Rico at Cayey), Dalvin Mendez (University of Puerto Rico at Cayey)

Abstract

H2S is a toxic gas but at low concentrations is beneficial to us. Once it is produced, it penetrates cell

membranes by simple diffusion and acts on target biomolecules to modulate numerous biological

responses. Several molecular targets have been identified, including proteins and enzymes in which H2S

regulates their activity via S-sulfhydration. Sulfhydration is the process by which H2S and other sulfide

oxidation products (H2Sx and HS?) attaches to cysteine residues in proteins, which then leads to either

activation or inhibition of protein activity. The sulfide species attach to free cysteine and cysteine

involved in disulfide bond (cystine). Many proteins are regulated by sulfhydration, including enzymes

involved in the progression of neurodegenerative diseases, such as Alzheimer's (AD) and Parkinson's

(PD). The chemical reaction of protein sulfhydration and how this product regulates protein activities are

unknown. It is unclear whether H2S or H2Sx/HS? sulfhydrate proteins. It is also unknown if these

molecules attack free cysteine thiols or disulfide bonds. The overall goal of this research is to define the

chemical reaction of sulfhydration in cysteine and cystine. The central hypothesis is that H2Sx will react

with free thiols like cysteine, while H2S will interact with disulfides such as cystine. To test this

hypothesis, the reactivity of H2Sx with cysteine was evaluated using kinetics and thermodynamics

approaches. UV-visible spectroscopy was used to follow the reaction of cysteine with H2Sx at the

maximum absorption band of H2Sx (300 nm). The reaction of cysteine with H2S was also evaluated at

250, 260 and 270 nm, which are associated with H

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