Lipids

Lipids

Lipids are natural products more soluble in nonpolar solvents than in water.

Some of them are related in that they have acetic acid (acetate) as their biosynthetic origin.

Acetyl coenzyme A serves as the source of acetate.

Some of them are related in that they have isoprene as their biosynthetic origin.

Fats, Oils, and Fatty Acids

Fats and Oils

Fats and oils are naturally occurring mixture of triacylglycerols (also called triglycerides).

Fats are solids; oils are liquids.

RCOCH

CH2OCR'O

CH2OCR"

O

O

O

R'COCH

CH2OCRO

CH2OCR"

O

Fatty Acids

Acids obtained by the hydrolysis of fats and oils are called fatty acids.

Fatty acids usually have an unbranched chain with an even number of carbon atoms.

If double bonds are present, they are almost always cis.

H2OHOCH

CH2OH

CH2OH

O

HOCRO

R'COH

O

HOCR"

Which one of the following is a triacylglycerol (triglyceride), a fat?

A) B)

C) D)

Question

Question

When cetyl palmitate is subjected to saponification conditions (NaOH, H2O, heat) which two compounds will be formed?

A) CH3(CH2)15OH + HOCH2(CH2)14CH3

B) CH3(CH2)14CO2Na + NaO2C(CH2)14CH3

C) CH3(CH2)14CO2H + HOCH2(CH2)14CH3

D) CH3(CH2)15OH + NaO2C(CH2)14CH3

Question

Which of the following is not an expected product of the acid hydrolysis of fats?

A) CH3(CH2)12CO2H

B) HOCH2CH2(OH)CH2OH

C) CH3(CH2)16CO2H

D) CH3(CH2)14CO2H

Fatty Acids

Systematic name: (5Z, 8Z, 11Z, 14Z)-5,8,11,14-Icosatetraenoic acid

Common name: Arachidonic acid

H

H H

H

H HH

H

OH

O

O

HO

OH

COOH

Prostaglandin E2

OH

HO

OH

COOH

Prostaglandin F1

CO2

Hcyclooxygenase

Prostaglandins

aspirin inhibits enzyme

(Chimes?)

Diterpenes & PainAspirin’s Mode of Action - Prostaglandin Cascades

Aspirin Inhibits the Synthesis of Prostaglandins

(prostaglandin endoperoxide synthase)