ish of the unsa tura ted and sa tura ted fa ts

180.

M E T A B O L I S H O F T H E U N S A TURA T E D A N D S A TURA T E D F A TS

F. A . KUMMEROW

No chemical dis t inct ion exists between p l a s t i c f a t s (shortening) and vegetable o i l s (salad o i l s ) ; both contain glycerol connected t o or "ester i f ied" wi th three moles of fa t ty acid (Table 1). acids i n the comrnon edible fats vary from C4 t o C22 i n chain length and -7.9 t o 79.9% i n melting point. The unsaturated f a t t y acids i n edible fats vary from C (Markley '60). ing points of the unsaturated f a t t y acids are important t o t h e physical character is t ics of fats and o i l s .

The saturated f a t t y

t o C20 i n chain length and -1 t o -49OC i n melting point '$fe high melting points of the saturated and the l o w m e l t -

If the glycerol i s e s t e r i f i ed with more than t w o unsaturated f a t t y acids, i . e . , o le ic or l ino le ic acid, the resul t ing t r iglycer ide i s a l iquid or an ' 'oil" at room temperature. i s e s t e r i f i ed with only long chain saturated f a t t y acids o r only one mole of o le ic and two moles of palmitic o r s tear ic acid, the result ing t r ig lycer - ides i s a so l id or "fat" at room temperature (Table, 2). A study of isolated t r iglycer ides has shown t h a t the substi tution of one mle of o le ic f o r s tear ic acid i n an d -position i n t r i s t e a r i n f o r example lowers the melting point from 73 t o 38OC and the same subst i tut ion i n t r ipa lmi t in from 66 t o 35OC (Bailey '50). human being i s 37.ZoC, the & subst i tut ion of l ino le ic o r o le ic acid f o r one mole of s tear ic o r palmitic acid m a y change the physical character of the depot fa t and i t s a b i l i t y t o act as EL "cushioning agent" t o vital organs. These depot fats m a y become so f t and o i ly .

If, on the other hand, glycerol

When one considers t h a t the body temperature of a

N a t u r a l f a t s and o i l s have been found t o contain mixtures of t r iglycer ides which are uniquely character is t ic of a specif ic fat (Hilditch '56). As indicated by the melting points of isolated triglycerides, the physical properties of the mixture of t r iglycer ides are governed by the physical properties of the par t icu lar f a t t y acid which i s e s t e r i f i ed with the glycerol (Table 3). In ' 'soft" fats such as corn or cottonseed o i l , which c o n t a b the unsaturated o le ic and l ino le ic acids as the predominant f a t t y acids, "the o i l s " are composed of a high proportion of d i and t r i unsaturated glycerides. beef tallow, which contain the saturated, myristic, palmitic and s tear ic acids as the predominant f a t t y acids, "the f a t s " are composed of a high proportion of d i and tri saturated glycerides. Although coconut o i l i s a vegetable o i l , it i s c lass i f ied as a fat as it contains 84% tri saturated glycerides and i s a so l id at room temperature. Human adipose t i s sue fat and human milk fat are semi so l id fats with a high proportion of mono and d i saturated glycerides.

In "hard" fats such as coconut o i l , bu t te r fa t and

181.

The glycerides of human adipose t i s sue contain approximately 4% myristic, 25% palmitic, 7% stear ic , 6% palmitoleic, 46$ ole ic and 2% of f a t t y acids which are shorter than 14 o r longer than 18 carbon atoms i n chain length (Cramer and Brown '43). the "non essent ia l fatty acids" as they can a l l be synthesized i n t h e body f r o m non fa t precursors. They are also found i n corn o i l , beef tallow and la rd but i n different percentage composition i n each case. adipose t i s sue fa t i s composed of approximately 9% l ino le ic and 1% arachidonic acid which contain two and four double bonds respectively. These two f a t t y acids have been c lass i f ied the "essent ia l f a t t y acids" as l ino le ic acid cannot be synthesized by a n i m a l t i s sue and serves as an essent ia l precursor f o r the synthesis of arachidonic acid.

These f a t t y acids may be c lass i f ied

In addition the

The a b i l i t y of unsaturated f a t t y acids t o form "geometric isomers", plays an important ro le i n the degree of hardness of a "hydrogen- ated" fa t such as margarine (Table 4) and probably of human depot fats. Geometric isomers are important t o the p l a s t i c i t y of fats because the - t rans isomers of o l e i c and l ino le ic acid, which are produced during the commercial hydrogenation of an edible o i l have melting points of 52OC and 29OC respectively and therefore tend t o "harden" margarine. c i s isomers of o le ic and l ino le ic acid have melting points of 14OC and m C respectively and therefore tend t o "soften" margarine at room temper- ature o r 21OC. a so l id o r a l iqu id state at room temperature i s important t o the produc- t i o n of margarines of high l ino le ic acid content f o r two reasons. One, even though the trans isomers of o le ic and l ino le ic acids influence the p l a s t i c i t y of margarine, these t rans isomers have the same degree of un- saturation o r iodine number as the natural cis isomers and therefore both contribute t o the calculated tfpolyunsaturates" and both thus increase the polyunsaturated t o saturated o r P/S r a t i o of t he fa t . Two, the deliberate production of t he high melting t rans o le ic and l ino le ic acid during com- mercial hydrogenation allows the margarine mnaufacturer t o add a higher percentage of the low melting l ino le ic acid t o a margarine fat without sacr i f ic ing t h e degree of desirable hardness. Thus mdern margarines, whether m a d e from corn o i l , cottonseed o i l , o r soybean o i l , all contain two t o three t i m e s more l ino le ic acid then a few years ago, but they also con- t a i n more t rans o le ic acid.

The natural

This property of o le ic and l ino le ic acids t o ex i s t i n either

W e purchased four typ ica l brands of both high and low priced margarine at a loca l supermarket and subjected them t o f a t t y acid and infrared analysis (Table 5 ) . of them contained more l ino le ic acid than the margarines which were avail- able a f e w years ago (Bailey '51). was independent of t h e i r l ino le ic acid content; t h e lowest priced margarine contained 15% more l ino le ic acid than the medium priced brand and only 54 less l i no le i c acid than the highest priced brand. The large arnount of "trans" f a t t y acid i n all of t he margarines indicated tha t both t r ans o le ic and trans, t rans l ino le ic acid may have been produced during t h e hydrogen- ation of soybean o i l , which forms the base stock of most margarines.

The resu l t s (Kummerow '64) indicated tha t a l l

F u r t h e m r e , t he cost of these margarines

The t rans f a t t y acids present i n human t i s sue apparently arise solely from dietary fat, and as i n rats, they do not normally appear i n the tissues unless a source of t rans fa t ty acids i s included i n the diet . Samples of fa t from human placental, maternal., f e t a l , and baby t i s sue were

182.

examined f o r the presence of t rans f a t t y acids. While the maternal t i s sue contained considerable amounts of trans f a t t y acids, these l i p ids were not found t o any measurable extent i n placental, f e t a l , or baby f a t (Johnston '58) a

The percentage of t rans f a t t y acids i n rat f a t decreased when t rans f a t t y acids were removed from the d i e t (Johnston '58a). However, they did not completely disappear from the tissue even at t h e end of two months on a d i e t f r ee of trans fatty acid. After one month on the d i e t f r ee of trans fat ty acid, the carcass fa t of the rats which had received 10% of margarine stock had decreased from 18.6 t o 6.5% and after two months t o 4.4% of t rans f a t t y acids. ceived margarine stock and ol ive o i l contained approximately 11% of t rans f a t t y acids. cass f a t decreased t o 4.9% and after two months t o 2.8% of trans - f a t t y acids. It seems evident t h a t the high t rans f a t t y acid content of marga- r ine fat could "harden" human depot fat and counteract the "softening" in- fluence of l ino le ic acid. indicate a higher P/S r a t io . character is t ics of t he depot fat might not be changed s ignif icant ly from a depot fa t which contained s tear ic instead of trans o le ic acid, t h a t i s someone eating bu t t e r f a t instead of margarine.

The carcass fat of the animals which had re-

After one month on a diet f r e e of t rans f a t t y acids, t he car-

The iodine value of such depot fa t would However, t h e melting point and other physical

The palmitic and s tear ic acid which i s found i n t i s sue f a t does not have t o be consumed as a component of dietary fa ts . wi th the aid of CI4 labeled acetic acid (two carbon atoms long i n chain length) t h a t f a t t y acids can be shortened o r elongated -- i n vivo so t h a t t r iglycer ides specific t o each species can be synthesized i n animal t i s sue . For example (Table 6), it has been shown that s tear ic acid can be converted t o palmitic acid through the collaboration of f i v e different enzymes and the presence of the proper cofactors (Bloch '60). coenzyme A adds t o s tear ic acid and two carbon atoms are removed as acetyl Co A. The resul t ing palmityl Co A can add -- i n vivo t o a dig1ycerj.de t o pro- duce a t r iglycer ide which contains one mole of p d m i t i c instead of s tear ic acid. When it i s not needed f o r t r iglycer ide synthesis, the palmityl Co A can be degraded u n t i l a l l of it i s converted t o acetyl Co A.

It has been shown

In the overal l reaction

The acetyl Co A, i n the presence of bicarbonate, adenosine triphosphate and b io t in enzyme, can be carboxylated t o form malonyl Co A (Table 7). nucleotide (TFNH) and with the elimination of water can be converted back t o palmitic acid (Lynen '61). In the process of synthesis, both palmitic and s tear ic acid can be dehydrogenated t o palmitoleic o r o le ic acid respec- t i ve ly . Thus with the aid of a dietary source of essent ia l f a t t y acids, animal t i s sue can produce f a t t y acids of proper chain length and t h e degree of unsaturation which i s best suited f o r i t s needs. However, the excessive consumption of dietary sources of essent ia l f a t t y acids such as corn o i l w i l l contribute t o t h e "metabolic pool" of acetyl Co A as effect ively as an excessive consumption of animal fats. F u r t h e m r e , when t i ssues are flooded with large arrounts of a highly unsaturated fat, they appear t o accumulate i n t i s sues i n abnormal amounts (Chu and Kummerow '50). (Table 8).

The malonyl Co A i n t h e presence of reduced triphosphopyridine

Under normal conditions carbohydrates furnish the major r a w material f o r the synthesis of f a t t y acids. Pyruvic acid (Table 9 ) by means

183.

of oxidative decarboxylation forms acetyl Co A. Metabolic pathways are also available f o r t he synthesis of f a t t y acids from amino acids. The glucogenic amino acids are convertible t o pyruvic acid; the ketogenic amino acids form acetate o r acetoacetate both of which are lipogenic. cases acetyl Co A i s the immediate s t a r t i ng material f o r the formation of f a t t y acids.

In a l l

The "metabolic pool" of acetyl Co A does not ex i s t as such but i s i n a continuous state of flux. If the dietary intake of metabolites i s j u s t suff ic ient o r is m a d e def ic ient by the excessive use of muscles and acetyl Co A i s used up i n t he c i t r i c acid cycle t o produce heat and energy (I), the conversion of acetyl Co A t o f a t t y acids (11) and cholesterol (111) would be minimal. However, i f the t o t a l calor ic intake i s i n excess of energy and maintenance requirements, acetyl Co A i s converted t o f a t t y acids and cholesterol. The major portion of the excess serum cholesterol i s convertedto b i l e acids i n the l i v e r and excreted. However, the excess f a t t y acids are deposited as t r iglycer ides and along with cholesterol, phospholipids and other l i p ids add t o the unwanted deposits of t i s sue fats. It i s therefore essent ia l t o balance the energy requirements against t o t a l calor ic need i n order t o prevent an accumulation of t i s sue fats. The adipose t i s sue fa t and serum cholesterol leve l can be reduced by increasing energy expenditures o r by decreasing calor ic intake. However, the obesity problem attests t o the f a c t t h a t it i s d i f f i c u l t t o carry out 812 orderly metabolism of nutr ients i n an atmosphere of dietary abundance.

The highly unsaturated f a t t y acids have been divided in to three families (Mead ' 6 0 ) , the oleic , l inoleic , and l inolenic acid families re- spectively (Table 10). elongated and desaturated t o a ser ies i n which the first double bond i s located at the 9th, 6th or 3rd posit ion from the methyl end of t he f a t t y acid chain. ending; it exis t s t o an appreciable extent i n fa t -def ic ient animals. In such animals a considerable amount of a C20 t r i p l e unsaturated 5,8,11- eicosatrienoic acid i s formed by elongation of o le ic acid, by the addition of acetyl Co A and by desaturation of t he carbon chain. The l inoleic de- rived family present i n dietary fats i s characterized by the CH3(CH2)4 terminal group of the "essential" l ino le ic acid and i ts elongated deriva- tive, t h e C20 arachidonic acid. The l inolenic family i s characterized by the CH3CH2 end group and i s found i n the serum l ip ids of animals fed l inolenic acid. Holman and Mohrhauer ('63) believe t h a t when linolenic acid is present i n the dietary fa t i t s conversion t o higher unsaturated f a t t y acids takes precedence over the metabolism of l inoleate by a fac tor near tenfold. Linoleate metabolism proceeds i n preference t o oleate metabolism and oleate metabolism t o higher unsaturated acids can take place only when l inoleate and l inolenate are present i n low concentration.

Curing t h e i r metabolism these f a t t y acids are

The elongated o le ic family i s characterized by the CH3(CH2)3

Mead ('60) has traced the steps involved i n the conversion of l ino le ic t o arachidonic acid. However, t o date, the degradation of l ino le ic acid has not been f u l l y elucidated. saturated fatty acids are first biohydrogenated and then degraded in to two carbon un i t s o r whether they are desdurated fur ther before they are metabolized. W e are presently following the metabolism of t r i t i um labeled l ino le ic acid, which has been prepared i n our laboratory, and hope t o c l a r i f y t h i s point i n the near future.

It i s not known whether un-

184.

An in te res t ing relat ionship between the three families of unsatu- ra ted f a t t y acids (Table 11) has been noted when they are incorporated in to Vitamin E def ic ient d i e t s . cause exudative diathesis i n chick and muscular dystrophy i n rats, rabbits, sheep and c a t t l e . However, only the e s sen t i a l f a t t y acids of the l i no le i c acids se r i e s cause chick encephalomalacia (Kummerow '64).

A l l th ree famil ies of unsaturated f a t t y acids

Since polyunsaturated f a t t y acids are incorporated in to the l i p i d s which are involved i n the surface s t ruc ture of t he c e l l w a l l , d ie ta ry fac- t o r s may exert some influence on t h e i n t e g r i t y of t h e c e l l s . For example (Walker '64) var ia t ion of the d ie ta ry fa t and t h e omission of Vitamin E f romthe diet resul ted i n changes i n the s t ab i l i t y of erythrocytes. Vitamin E deficiency resul ted i n t h e most s ignif icant changes, whereas the nature of the d ie ta ry f a t tended t o modify the degree of change. The c e l l s from Vitamin E-supplemented rats showed l i t t l e o r no hemolysis; wi th corn o i l t he degree of hemolysis was greater than w i t h the more saturated lard. placement of c e l l u l a r oxygen with carbon monoxide inhibi ted t h i s hemolytic ac t iv i ty , which i s consequently believed t o be oxidative i n nature.

Re-

I n another s e r i e s of experinents, t he importance of the e s sen t i a l f a t t y acids t o the s t ruc tu ra l i n t eg r i ty of t h e c e l l w a s studied (Walker '64). A n increasing amount of d ie ta ry l ino le ic acid as supplied by coconut o i l , bu t te r fa t , castor o i l and corn o i l resul ted i n increased incorporation of l ino le ic acid in to the c e l l w a l l of erythrocytes and also t o increased arachidonic acid incorporation (Table 1 2 ) . Where dietary l ino lea te was re- s t r ic ted , more palmitoleic and o le ic acids were incorporated in to the c e l l u l a r l i p ids , and the eicosatrienoic acids charac te r i s t ic of e s sen t i a l f a t t y acid deficiency w e r e also found i n increasing amounts, comprising over 16% of the t o t a l f a t t y acids when hydrogenated coconut o i l was the d ie ta ry fat .

The erythrocytes f romthese animals were subjected t o hemolysis by isotonic solutions of th ree non-electrolytes glycerol, thiourea and tri- ethylene glycol. With each solute studied, t he hemolysis resu l t ing from the permeation of the solute in to t h e c e l l was most rapid i n c e l l s from the a n i m a l s fed coconut o i l . As t he d ie ta ry l i no le i c acid intake increased, the r a t e of hemolysis decreased. s t ruc tu ra l changes a r i s ing i n the erythrocyte membrane from the incorpora- t i o n of specif ic f a t t y acids.

It i s possible t h a t hemolysis re f lec ted

I n a recent report, Vendenheuvel ( ' 6 3 ) advanced a model f o r bio- log ica l organization at the molecular level . resu l t ing from the association of cholesterol with sphingomyelin or glycerophosphatide and w a s applied spec i f ica l ly t o the s t ructure of the myelin sheath. t he ro l e of the e s sen t i a l f a t t y acids i n the phospholipid of such complexes (Fig. 1). the parameters given by Vandenheuvel, the d -position of t he glycerol moiety i s esterified with s t ea r i c acid (ABC) and the &-posi t ion with arachidonic (ABDE) or 5,8,11-eicosatrienoic acid (ABDF). proposed by Vandenheuvel, the curvature of the arachidonic acid chain would r e su l t i n greater stearic hindrance t o the cholesterol than would mono- or dienoic acids. However, t h e subst i tut ion of the t r ienoic acid for t h e arachidonic acid also r e su l t s i n an increase i n t h e over-al l width of t h e

This model involved a complex

It i s interest ing, however, t o consider the poss ib i l i t y of

I n a representation of l ec i th in constructed geometrically from

I n a complex such as tha t

185.

l ec i th in moiety. arachidonyl-lecithin. It i s tempting t o speculate tha t some of the prop- erties of c e l l membranes may be governed by the type of f a t t y acid i n the complex. ra ted f a t t y acids are incorporated in to the c e l l at the expense of arachidonic acid, a change i n s t ructure of the molecules may occur and m a y result i n a looser packing of the phospholipid complexes i n the membrane thus a l te r ing i ts s t a b i l i t y and permeability.

This increase, Y, i s about 20% of the width, X, of the

For example, when the o le ic o r l inolenic series of polyunsatu-

It is interest ing t o note t h a t the c18 - cis-9, trans-12, octadecadienoic acid, a possible component of hydrogenated soybean o i l , can be elongated and desaturated t o the Czo, 5,8,11,14-eicosatetraenoic acid, the C18 t rans f a t t y acid w i l l not prevent t he symptoms of essent ia l f a t t y acid deficiency. The Cz0 f a t t y acid i s a geometric isomer of arachidonic acid with a t r a n s double bond i n the 14- position. The orthogonal projec- t i o n of a phosphatide containing t h i s C 2 0 f a t t y acid would be very similar t o t h a t of t he phosphatide containing the non-essential eicosatrienoic derived from ole ic acid and m a y also alter the s t a b i l i t y and permeability of erythrocytes. f a t t y acids i n the t i s sue lipids may influence t h e in tegr i ty of c e l l membranes.

Thus a simple change i n the composition of the unsaturated

SUMMARY

I n summary, dietary fats represent the most compact food energy source available t o man. However, dietary f a t s should not be thought of solely 88 providers of unwanted calor ies as fats are as v i t a l t o c e l l s t ructure and biological function as protein. Tissue fa t can be synthe- sized from either carbohydrate o r protein, therefore, the t o t a l calor ic intake rather than any one dietary component i s c ruc ia l t o t he amount of deposition of l i p ids in to the t i s sue .

An optimum intake of essent ia l f a t t y acids may be important t o the in t eg r i ty of the c e l l w a l l of erythrocytes. picture of t he ro le of dietary fats i n optimum nut r i t ion i s c lar i f ied, it would seem judicious t o consume a well-balanced d ie t of meat, milk, eggs, vegetables, fruits, and suff ic ient cereals and bread t o provide f o r an ade- quate protein, vitamin, and calor ic intake. The optimum t o t a l intake of l ino le ic acid by man has not been established. The l eve l of l ino le ic acid i n the American dietary pat tern could be increased through the ava i lab i l i ty of less severely hydrogenated shortenings but the indiscriminate dietary substi tution of "soft" f o r "hard" fats seems undesirable.

However, u n t i l the en t i r e

REFERENCES

Bailey, A. E. 1950 Melting and Sol idif icat ion of Fats . Interscience Publishers, New York, p . 166.

Bailey, A. E. 1951 Indus t r ia l O i l and Fat Products. Interscience Publishers, New York, p . 759.

186.

Bloch, K. 1960 Lipid Metabolism. John Wiley & Sons, New York, p. 41.

Chu, T. K. and F. A. Kummerow 1950 The Deposition of Linolenic Acid i n Chickens Fed Linseed O i l . Poultry Sci. , - 24: 846.

Cramer, D. L. and J. B. Brown 1943 The Component Fat ty Acids of Human Depot Fat . J. Biol. Chem., 151: 427.

Hilditch, T. P. 1956 The Chemical Constitution of Natural Fats. John Wiley & Sons, New York, p. 391.

Johnston, P. V., D. C. Johnson and F. A. Kummerow 1958a Deposition i n Tissues and Fecal Excretion of Trans Fatty Acids i n the R a t . J. Nutrition, - 65: 13.

Johnston, P. V., F. A. Kummerow and C. H. Walton 1958 Origin of Trans Fatty Acids i n Human Tissue. Doc . SOC. Exptl. Biol. Med., - 99: 735.

Kummerow, F. A. 1964 The Possible Role of Vitamin E i n Unsaturated Fat ty Acid Metabolism. Fed. Proc., i n press .

Kummerow, F. A. 1964 The Role of Polyunsaturated Fat ty Acids i n Nutrition. Food Tech., i n press .

Lynen, F. 1961 Biosynthesis of Saturated Fat ty Acids. Fed. Proc., g :941.

Markley, K. S. 1960 Fat ty Acids. Interscience Publishers, New York, p. 34.

Mead, J. F. 1960 Metabolism of the Polyunsaturated Fat ty Acids. Am. J. Clin. Nutrition, - 8: 55.

Mohrhauer, H . and R. T. Holman 1963 The Effect of Dietary Essential Fat ty Acids Upon Composition of Polyunsaturated Fat ty Acids i n Depot Fat and Erythrocytes of t he Rat. J. Lipid Res., 4: - 346.

Vendenheuvel, F. A. 1963 Study of Biological Structure at the Molecular Level with Stereomodel Projections. I. The Lipids i n the Myelin Sheath of Nerve. J. Am. O i l Chem. SOC., - 40: 455.

Walker, B. and F. A. Kummerow 1964 Dietary Fat and the Structure and Properties of R a t Erythrocytes. J. Nutrition, - 82: 323.

Walker, B. and F. A. Kummerow 1964 Erythrocyte Fat ty Acids and Apparent Permeability t o Non Electrolytes. h o c . SOC . Exptl. Biol. Med., 115: 1099. -

187.

TABLE 1

Melting; Points of Fat ty Acids

Saturated

m.p .OC c4 Butyric -7.9

c6 Caproic -3.4

cg Caprylic 16.7

Cl0 Capric 31.6

C12 Lauric 44.2

Uns a tura t ed

Palmitoleic '16 : 1

%8:1 Oleic

Linoleic

Ar ac h i donic

%8:2

c20:4

Glyceride

s-s-s

s-s-0 s-0-s

s-0-0

L-0-0

m.p .OC C14 m i s t i c 54.4

c16 Palmitic 62.9

C18 Stearic 69.6

Cz0 Arachidic 75.3

C22 Behenic 79.9

-1

14

-12

-49

TABm 2

The Effect of Unsaturated Fat ty Acids on the MeltiG --- -Triglyceride

- ---

M.P. Glyceride - 73% P-P-P

38

43

23

7

P-0-P

P-0-0

M-0 -0

M.P. - 66OC

35

19

14

O-Oleic; P-Palmitic; S-Stearic Acid; L-Linoleic; M-Myristic

188.

TABLE 3

Glyceride Composition - of Vegetable - and A n i m a l Fats - G S 3 GSzU GSU2 A- - ?b 2

corn oil 1 15 45 38

Cottonseed o i l 0 13 44 43

Coconut o i l 84 1 2 4 0

Butterfat 35 36 29 0

Beef tallow 15 46 37 2

Lard 2 26 55 17

Human (adipose) 5 26 43 24

Human (milk) 9 40 43 8

S - Saturated f a t t y acid U - Unsaturated f a t t y acid

TABLE 4

Melting Points of C i s and T r a n s Isomers ----

C------x x-----c C Y C Y ll 11

Oleic Elaidic m.p. 14'C m . p . 52OC

X d X 4

C + 4 C----c-----c

C Y C Y

11 I1

I I l l

Linoleic Linoelaidic m . p . -12 '~ m.p. 29OC

189.

TABLE 5

Comparative Composition of Margarines

Fa t ty Acid

Palmitic

Stearic

T o t d sat.

Oleic

Linoleic

Total Unsat.

Total "Trans"

M39#

14.7

7.3

22.3

41.7

35.4

77.1

28.7

F39#

16.2

9.3

25.7

43.4

30.2

73.6

19.6

A29k 9.4

5.1

14.8

73.3

10.8

84.1

43.6

TABI;E 6

Conversion of Stearic Acid to Metabolic Products

a3(CH2)16CmH + 2HSCoA

(Stearic Acid) + (Coenzyme A)

CH3(CH2) 14COOH + CH3COSCoA

(Palmityl CoA) + (Acetyl CoA)

11.7

13.0

25 .O

47.5

25.8

73.3

48.6

1 BCH~COSCOA (Acetyl CoA)

190.

TABLE 7

The Synthesis of Palmitic Acid - -

CH3COSCoA + HCO3 + HOOCCH2COSCoA

(Acetyl CoA) (Carbonate) (Malonyl CoA)

CH~CHZCH~COSCOA (Butyryl CoA) J 1

CH; ( CH2) 14COSCoA (Palmityl CoA) &

TABLE 8

Acetone Soluble - and Insoluble Oleic

- and Linolenic --- i n Skin Fat

Dietary Oleic Lin. o i l Soluble Insoluble

Linolenic Soluble Insoluble

0% 23.3% 30.8% 0.8% 0.3%

6% 16.2% 39.$ 20.7% 0.9%

1% 24.7% 47 .s$ 22.276 1.1%

2570 21-85 50 .l$ 28.0% 1.2%

191.

TABLE 9

Relations hip - of Metabolites

Carbohydrate Protein

Pyruvate -C02 4

Acetyl -m2 amino +CoA acids

4 +&A '

I I I1 I11 A I -

I Citrate Oxbo - A Long'chain st eio 1s

acetate f a t t y acids ( CH~-CHZ)~COOH

u coz+H20 -2H

Oleic acid + depo s i t ed

i n t i s sue

1 b i l e acids excreted

(heat & energy)

TABLE 10

Metabolites of the Three Unsaturated Fatty Acid Families

All 9 eicosa- eico s a- oleic -b dienoic _____.) t r ienoic 18:l 20:2 20:3

All 6 machi- doc0 6 a- linoleake .-b donate -b pentaenoic 18:2 20:4 22:s

A l l 3 e ic os a- doc 0 S a-

18:3 20:5 22:s linolenate -+ pentaenoic .-) pentaenoic

6,9,12,15 arachidonic acid

192.

TABLE 11

Pathology Caused bz Vi tamin E, Deficiency

Pat ho logy symptom C a s e Delayed by

1. Exudative diathesis Edema PUFA Se

2. Myopathy rnscular S amino acids 11 dystrophy

3. Encephalo- Spasm or EFA Linolenic malacia paralysis series

TABLE 12

Fatty Acid Composition of the Erythrocyte Lipids

Acid

16:O

16:l

18:O

18:l

-

1a:2

20:3

20: 3

20:4

Coconut 0 i 1

22.4$

2.7

14.2

15.7

2.2

15 .O

1 .o

15.4

Castor o i l

2s. 2%

1.7

13.5

13.5

5 .3

1.3

1.1

26.3

corn O i l

24.2$

0.4

13.5

8.6

11.5

0.1

0.5

31 .O

153.

PHOSPHATIDYL CHOLINE

C

0 GLYCCEROL C m

0 OXYGEN -0 -

OXYGEN =O

. .e... . . . @ OXYGIEN -0- .. V .... .d .... .’

F NITROGEN

ABC - STEARIC ACID

ABDE - ARACHIDONIC ACID

A PHOSPHORUS

ABOF - ECOSATRIENOIC ACID

Figure 1

DR. KASTEWC: Thank you, Dr. -row. I thipk we w i l l withhold questioning un t i l af ter we have had an opportunity t o hear the next paper. I take great pleasure i n introducing Dr. Hector DeLuca, who is a member of the Department of Biochemistry here at the University of Wisconsin, a w e l l known biochedst. I understand now that he is following the interest of Dr. Steenbock, as might be surmised fromthe topic of his discussion th i s after- noon. I take pleasure i n welcoming him t o t h i s group. D r . DeLuca,

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