CHEM 30B  Dr. R. Rinehart
Chapter 18: Lipids
Here’s a major hunk of fat to chew on! Hope you can digest it!!!

Fatty Acids

common name

shorthand
notations
#of C : # of C=C
#of C, location of C=C

line structure

comments

butyric acid

4:0




in butterfat

lauric acid

12:0




in coconut oil

myristic acid

14:0




in nutmeg oil

palmitic acid

16:0





in palm oil

palmitoleic acid

16:1
C16D9




in oils and fats

stearic acid

18:0




beef tallow and human fat

oleic acid

18:1
C18D9




olive oil, lard, and human fat

linoleic acid

18:2
C18D9,12




in many vegetable oils and linseed oil

a-linolenic acid

18:3
C18D9,12,15




the g- isomer D6,9,12 is not as essential

arachidonic acid

20:4
C20D5,8,11,14




precursor to prostaglandins, prostacyclins, and thromboxanes

eicosapentaenoic
 acid [EPA]

20:5
C20D5,8,11,14,17


try drawing it! all the C=C are cis

an (w-3) fatty acid

docosahexaenoic
 acid [DHA]

22:6
C22D4,7,10,13,16,19


try drawing it! all the C=C are cis

an (w-3) fatty acid

Waxes

beeswax


is actually a mixture of fatty esters and hydrocarbons. see below for a typical component, where the acid and the alcohol both have 26 carbons; the length of the fatty acid can range from 18? to 36 C and the alcohol from 24 to 36 C

a most useful material!
[to us as well as to them]




Glycerolipids

class

general structure

comments

triglyceride




if solid, it’s called a fat; if liquid, an oil. Melting point depends on chain length and degree of unsaturation.

diglyceride




formed during fat digestion and used as food additive [emulsifier]

monoglyceride




formed during fat digestion and used as food additive [emulsifier]

phosphatidic acid




building block of glycerophospholipids

lecithin

phosphatidyl choline




a key cell membrane component

cephalin

phosphatidyl ethanolamine




another common cell membrane component

cephalin
phosphatidyl serine




another common cell membrane component

phosphatidyl inositol




a less-common membrane component

Sphingolipids

sphingosine




the basic building block of sphingolipids, ~ never found free

ceramide

N-acyl sphingosine




the usual form from which sphingolipids are assembled

sphingomyelin




the only phosphorus-containing class of sphingolipids

cerebroside




sugar is usually gal, can be glc

ganglioside


I’m not even going to try to fit it here!

variable branched oligosaccharides

Steroids

sterane




 

cholesterol




 

sodium taurocholate




a “bile salt” sysnthesized in the liver from cholesterol and used to emulsify fat during digestion.

cortisol




elevates blood glucose levels, promotes breakdown of muscle protein and subsequent catabolism of amino acids; antiinflammatory, suppresses immune system activity.

cortisone




semisynthetic antiinflammatory agent

prednisolone




a synthetic antiinflammatory steroid

aldosterone




the main mineralocorticoid; promotes sodium reabsorption and potassium excretion in the kidneys

testosterone




the major androgen; increases muscle mass and induces male secondary sexual characteristics

androstenedione




alleged to be a human pheromone, it’s also the stuff Mark McGwire used [baseball’s drug policies are a lot laxer than those of other sports]

Dianabol




the most popular synthetic anabolic steroid; widely abused, produces “roid rage”
has been said to cause liver cancer

b-estradiol




the major estrogen; prevents osteoporosis and may help protect against cardiovascular conditions.

diethylstilbestrol




synthetic compound with estrogen activity; caused cervical cancer in the daughters of women who took it as a fertility agent in the ‘50s and ‘60s; used to fatten beef cattle.

progesterone




the main progestin; prepares uterine lining for implantation

Eicosanoids:
Prostaglandins, Prostacyclins, Thromboxanes, Leukotrienes

arachidonic acid




the precursor to the 1- and 2- series; EPA is the precursor to the 3- series

PGE2




has tissue-specific effects on smooth muscle

PGF2a




has tissue-specific effects on smooth muscle; E and F types usually mutually antagonistic

PGI2
prostacyclin




prostacyclins are produced by cells in the linings of blood vessels and antagonize thromboxane activity

TXA2
thromboxane




thromboxanes are produced by activated blood platelets and activate other platelets

LTA4
leukotriene A4




 

LTB4
leukotriene B4




 

LTC4
leukotriene C4, a.k.a. SRS-A




the “slow-reacting substance of anaphylaxis”

© Ronald W. Rinehart, 2002 
Structures drawn with CS ChemDraw® , MDL IsisDraw®, and ACD Labs ChemSketch®
 

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