Synthesis and application of a new copper(II) complex containing oflx and leof
3
704 ISSN 0036-0236, Russian Journal of Inorganic Chemistry, 2008, Vol. 53, No. 5, pp. 704–706. © Pleiades Publishing, Ltd., 2008. 1 2 Many drugs possess modified pharmacological and toxicological properties administered in the form of metallic complexes. Cu 2+ is probably the most widely studied in this aspect, since a host of low-molecular- weight copper complexes have proved beneficial in several diseases, such as tuberculosis, rheumatoid, gas- tric ulcers, and cancers [1–4]. There has been tremen- dous growth of drugs from the fluoroquinolone family. This began with the discovery of nalidixic acid (Hnal) 40 years ago. Since then, the exponential growth of this family has produced more than ten thousands of ana- logues [5]. The coordination chemistry of these drugs with metal ions of biological and pharmaceutical importance is of considerable interest. There have been several reports about the synthesis and crystal structure of metal complexes with cpf [6–9]. Levofloxacin was considered the best of the fluoroquinolone kind in the third generation. In the present work, we characterized the crystal structure of the complex I and complex II and reported their inhibitory effect on HL-60 cells. A solution of 0.5 mmol phen was added to 0.5 mmol Cu(NO 3 ) 2 · 3H 2 O aqueous solution. To this mixture was added 60 mL of 0.5 mmol NaOH solution containing 1 mmol Ofloxacin and Levofloxacin (Fig. 1); the pH of the solution was adjusted to 7.0–8.0 with HCl. The resulting blue solutions were slowly evaporated at room 1 The text was submitted by the authors in English. 2 Corresponding author. Tel: +862368252277; fax: 862368254000; e-mail: [email protected]. temperature. Two months later, blue crystals were formed (Fig. 2). The structures of the complexes were characterized by FT-IR. Comparing the spectra of complex I and complex II, they were congeneric complexes, so the structure of the complex I was discussed. In a compar- ison of the IR spectra of complex I and ligand ofloxa- Synthesis and Application of a New Copper(II) Complex Containing oflx and leof 1 Yan Li, Yaqin Chai 2 , Ruo Yuan, Wenbin Liang Chongqing Key Laboratory of Analytical Chemistry, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 P.R. China Received January 29, 2007 Abstract—Two new copper(II) complexes of [Cu(Ofloxacin)(phen)(H 2 O)] · (NO 3 ) · 2H 2 O and [Cu(Levoflox- acin)(phen)(H 2 O)] · (NO 3 ) · 2H 2 O were obtained and their structures were studies. Both ligands and complexes were assayed against gram-positive and gram-negative bacteria by the in vitro doubling dilutions method. The inhibitory effect of the ligands and complexes on the leukemia HL-60 cell line were measured with the MTT assay method and the liver cancer HePG-2 cell line measured by the SRB method. The results indicated that the complexes have stronger inhibitory effect on HL-60 than on HePG-2. The complex [Cu(Levofloxa- cin)(phen)(H 2 O)] · (NO 3 ) · 2H 2 O (I) has stronger effect on HL-60 than the complex (Cu(Ofloxacin)(phen)(H 2 O)] · (NO 3 ) · 2H 2 O (II). Keywords: copper(II) complex; fluoroquinolone; synthesis; antibacterial activity; antitumor activity; MTT assay. DOI: 10.1134/S0036023608050070 COORDINATION COMPOUNDS Ofloxacin Levofloxacin Fig. 1. Structure of Ofloxacin and Levofloxacin. N N N O H 3 C CH 3 F O COOH N N N O H 3 C CH 3 F O COOH H
Transcript of Synthesis and application of a new copper(II) complex containing oflx and leof
704
ISSN 0036-0236, Russian Journal of Inorganic Chemistry, 2008, Vol. 53, No. 5, pp. 704–706. © Pleiades Publishing, Ltd., 2008.
12
Many drugs possess modified pharmacological andtoxicological properties administered in the form ofmetallic complexes. Cu
2+
is probably the most widelystudied in this aspect, since a host of low-molecular-weight copper complexes have proved beneficial inseveral diseases, such as tuberculosis, rheumatoid, gas-tric ulcers, and cancers [1–4]. There has been tremen-dous growth of drugs from the fluoroquinolone family.This began with the discovery of nalidixic acid (Hnal)40 years ago. Since then, the exponential growth of thisfamily has produced more than ten thousands of ana-logues [5]. The coordination chemistry of these drugswith metal ions of biological and pharmaceuticalimportance is of considerable interest. There have beenseveral reports about the synthesis and crystal structureof metal complexes with cpf [6–9]. Levofloxacin wasconsidered the best of the fluoroquinolone kind in thethird generation. In the present work, we characterizedthe crystal structure of the complex
I
and complex
II
and reported their inhibitory effect on HL-60 cells.
A solution of 0.5 mmol phen was added to 0.5 mmolCu
(
NO
3
)
2
·
3
H
2
O aqueous solution. To this mixture wasadded 60 mL of 0.5 mmol NaOH solution containing1 mmol Ofloxacin and Levofloxacin (Fig. 1); the pH ofthe solution was adjusted to 7.0–8.0 with HCl. Theresulting blue solutions were slowly evaporated at room
1
The text was submitted by the authors in English.
2
Corresponding author. Tel: +862368252277; fax: 862368254000;e-mail:
temperature. Two months later, blue crystals wereformed (Fig. 2).
The structures of the complexes were characterizedby FT-IR. Comparing the spectra of complex I andcomplex II, they were congeneric complexes, so thestructure of the complex I was discussed. In a compar-ison of the IR spectra of complex I and ligand ofloxa-
Synthesis and Application of a New Copper(II) Complex Containing oflx and leof
1
Yan Li, Yaqin Chai
2
, Ruo Yuan, Wenbin Liang
Chongqing Key Laboratory of Analytical Chemistry, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 P.R. China
Received January 29, 2007
Abstract
—Two new copper(II) complexes of [Cu(Ofloxacin)(phen)(H
2
O
)]
·
(
NO
3
)
·
2
H
2
O and
[
Cu
(
Levoflox-acin
)(
phen
)(
H
2
O
)]
·
(
NO
3
)
·
2
H
2
O were obtained and their structures were studies. Both ligands and complexeswere assayed against gram-positive and gram-negative bacteria by the in vitro doubling dilutions method. Theinhibitory effect of the ligands and complexes on the leukemia HL-60 cell line were measured with the MTTassay method and the liver cancer HePG-2 cell line measured by the SRB method. The results indicated thatthe complexes have stronger inhibitory effect on HL-60 than on HePG-2. The complex
[
Cu
(
Levofloxa-cin
)(
phen
)(
H
2
O
)]
·
(
NO
3
)
·
2
H
2
O
(
I
)
has stronger effect on HL-60 than the complex (Cu
(
Ofloxacin
)(
phen
)(
H
2
O
)]
·
(
NO
3
)
·
2
H
2
O
(
II
).
Keywords:
copper(II) complex; fluoroquinolone; synthesis; antibacterial activity; antitumor activity; MTTassay.
DOI:
10.1134/S0036023608050070
COORDINATIONCOMPOUNDS
Ofloxacin
Levofloxacin
Fig
. 1.
Structure
of
Ofloxacin
and
Levofloxacin
.
N
N N
OH3C CH3
F
O
COOH
N
N N
OH3C CH3
F
O
COOH
H
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY
Vol. 53
No. 5
2008
SYNTHESIS AND APPLICATION OF A NEW COPPER(II) COMPLEX 705
cin, there were some obvious changes. The ligands ofofloxacin have two characteristic absorption peaks,1702 and 1623 cm
–1
; the first was the C=O vibrationabsorption peak from carboxylic acid oxygen, and thesecond was assigned to keto C=O peak from the ring ofofloxacin. However, the 1702 cm
–1
peak disappeared inthe complex, so the carboxylic acid oxygen was coordi-nated with Cu
2+
[10]. At the same time, the keto oxygenwas coordinated with Cu, the peak of which shifted to1585 cm
–1
, so 1625 and 1456 cm
–1
were
ν
a
and
ν
s
of car-bosylate,
∆ν
= 169
cm
–1
. From the IR spectra of fluoro-quinolone complex, it was known that carboxylic acidoxygen was single coordination [11]. Comparing theligand with the complex at 1800–3500 cm
–1
, the complexhad a wide and strong absorption peak at 3399 cm
–1
(thepeak of the ligand was at 3405 cm
–1
), the absorptionpeaks at 2843, 2342, and 1921 cm
–1
showed hydrogenbonds in molecule or between molecules. The peak ofring vibration from the free phen was at 1560 cm
–1
andthe peak of phen in the complexes was at 1519 cm
–1
,indicating that the phen was coordinated with Cu
2+
.
There was a free N characteristic vibration peak at
1385
cm
–1
, indicating that N was not coordinated. At
551
cm
–1
, there was swing vibration absorption
ρ
w
(
H
2
O
)
peak of H
2
O, indicating that H
2
O was coordi-nated with Cu
2+
.
In conclusion, from the FT-IR spectra analysis of theligand ofloxacin and its complex, the cooper(II) atomwas coordinated to the keto oxygen and the carboxylicacid oxygen, 1,10-phenanthroline and H
2
O to form afive-membered ring. The copper atom displayed a five-coordinate square pyramidal coordination with twonitrogen donors from 1,10-phenanthroline, the 4-ketoand 3-carboxylate oxygen donors, and H
2
O occupyingthe fifth site.
Both ligands and complexes were assayed againstEscherichia coli(G–), Pseudomonas aeruginosa(G–),Staphylococcus aureus(G+), and Streptococcus pneu-moniae(G+) by the in vitro doubling dilutions method.The results indicated that both ligands and complexeshad inhibitory effect on Escherichia coli(G–),Pseudomonas aeruginosa(G–), Staphylococcusaureus(G+), and Streptococcus pneumoniae(G+). Theresults are showed in Table 1. Complexes I and II had astronger inhibitory effect on G– bacterium than G+bacterium. The complexes showed the same minimalinhibitory concentration (MIC) and minimal bacteri-cidal concentration (MBC) as the corresponding ligandagainst these bacteria; Cu
2+
did not have an obviouseffect on the antibacterial activity of fluoroquinolone.
The leukemia HL-60 cell and HeGP-2 cell remain-ing after appropriate treatment was determined bya 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT)assay [12, 13]. Briefly, cells wereplated (4000 cells/well per 0.2 mL RPMI 1640
O3–
O3–
medium) in 96 well microtiter plates and incubatedovernight. The test agent was then added at indicatedconcentrations to quadruplicate wells. After 48 h, MTTwas added to each well at a final volume of 0.5 mg/mLand the microplates were incubated at
37°
C for 3 h.After the supernatant was removed, the formazan saltresulting from the reduction of MTT was solubilized indimethyl sulfoxide (DMSO, Sigma Chemical Co.) andthe absorbance was read at 450 nm using an automaticplated reader. The cell viability was extrapolated from
Table 1.
Minimal inhibitory concentration (MIC, mg/mL)and minimal bactericidal concentration (MBC) of the drag forthe assayed bacteria
Bacteria Drug MIC (
µ
g/mL)MBC
(
µ
g/mL)
Pseudomonas aeruginosa
DMSO (1%) Ofloxacin Levofloxacin Complex
I
Complex
II
>512<20<20
2<1
>512<20<20
21
Escherichia coli 35218
DMSO Ofloxacin Levofloxacin Complex
I
Complex
II
>512<20<20<1<1
>512<20<20<1<1
Staphylococcus aureus
DMSOOfloxacin Levofloxacin Complex
I
Complex
II
>512<20<20
6464
>512<20<20
6464
Streptococcus pneumoniae
DMSOOfloxacin Levofloxacin Complex
I
Complex
II
>512<20<20
42
>512<20<20
42
N
N
N
N
NOCu
O
O
F
OH2
Fig
. 2.
Possible
structure of Cu(II) complex.
706
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 53 No. 5 2008
LI et al.
optical density (OD)450 values and expressed as percentsurvival using this formula, and a graph was plotted:
% Cell viability
=
The results indicated that two complexes had aninhibitory effect on the HL-60 and HePG-2 cell lines(Table 2). Complex I had stronger effect on HL-60 andHePG-2 cells than complex II, especially on HL-60.
ACKNOWLEDGMENTS
This work was supported by the National NaturalScience Foundation of China (20675064), the NaturalScience Foundation of Chongqing City, China (SCTC2004BB4149, 2005BB4100) and the High TechnologyProject Foundation of Southwest University(XSGX02).
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OD( )450 of drug treaded sampleOD( )450 of drug treaded sample
----------------------------------------------------------------------------- 100.×
Table 2. The complexes against various human cancer cell lines by MTT and SRB assay
CompoundHL-60/(mol L–1) HePG-2/(mol L–1)
10–4 10–5 10–6 10–7 10–4 10–5 10–6 10–7
Ofloxacin 21.5 5.1 0 0 12.1 0 0 0
Levofloxacin 37.8 17.4 0 0 19.3 3.4 0 0
Complex I 98.7 98.1 90.4 85.1 95.8 91.3 92.1 76.0
Complex II 99.2 98.5 96.7 88.4 96.9 93.0 90.4 73.6
