Linoleic acid -octadecadienoic

CCRIS 7064 Conjugated linoleic acid Octadecadienoic acid 9,11 (or 10,12)-Octadeoadienoic acid Octadeca-dienoic acid, conjugated. 

Linoleic acid Octadecadienoic acid 18 Two double bonds, usually in position 9 and 12... 

The major fatty acids present in plant-derived fatty substances are oleic acid (9-octadecenoic, C18 l), linoleic acid (9,12-octadecadienoic, C18 2) and the conjugated isomers thereof and linolenic acid (9,12,15-octadecatrienoic, C18 3) (Scheme 31.1). Their rates of oxygen absorption are 100 40 1, respectively, hence partial hydrogenation with consequent lowering of the iodine number would lead to a significant increase in oxidative stabihty, particularly when C18 3 is reduced. 

Hydroxy-10,12-octadecadienoic acid, which is formed by the reduction of 9-HPODE, was identified in the erythrocyte membrane phospholipid of diabetic patients [83]. It was suggested that this compound was formed as a result of glucose-induced oxidative stress in the reaction of hydroxyl radicals with linoleic acid. 

Inhibition and stimulation of LOX activity occurs as a rule by a free radical mechanism. Riendeau et al. [8] showed that hydroperoxide activation of 5-LOX is product-specific and can be stimulated by 5-HPETE and hydrogen peroxide. NADPH, FAD, Fe2+ ions, and Fe3+(EDTA) complex markedly increased the formation of oxidized products while NADH and 5-HETE were inhibitory. Jones et al. [9] also demonstrated that another hydroperoxide 13(5)-hydroperoxy-9,ll( , Z)-octadecadienoic acid (13-HPOD) (formed by the oxidation of linoleic acid by soybean LOX) activated the inactive ferrous form of the enzyme. These authors suggested that 13-HPOD attached to LOX and affected its activation through the formation of a protein radical. Werz et al. [10] showed that reactive oxygen species produced by xanthine oxidase, granulocytes, or mitochondria activated 5-LOX in the Epstein Barr virus-transformed B-lymphocytes. 

The traditional major source for the nonionic surfactant industry is fatty acid triglycerides from both animal and vegetable sources as the saturated or unsaturated acids. The saturated acids include lauric acid (w-dodecanoic), myristic acid (n-tetradecanoic), palmitic acid ( -hexadecanoic),and stearic acid (n-octadecanoic). The unsaturated acids include oleic acid (Z-9-octadecenoic) and linoleic acid (Z,Z-9,12-octadecadienoic). Of the 200 non-ionic surfactants... 

Figure 1. The chemical structures of linoleic acid (cis-9, cis-12-octadecadienoic acid), and the cis-9, trans-11 CLA isomer (cis-9,trans-l 1-octadecadienoic acid). (Reproduced with permission from the Food Research Institute Annual Report 1990. Copyright Food Research Institute 1991.)...

Figure C4.2.4 (A) SP-HPLC of methyl hydroxyoctadecadienoates obtained from linoleic acid hydroperoxide products. Peak 1, methyl 13-hydroxy-9(Z),11( )-octadecadienoate peak 2, methyl 13-hydroxy-9( ),11(E)-octadecadienoate peak 3, methyl 9-hydroxy-10(E),12(Z)-octadecadi-enoate peak 4, methyl 9-hydroxy-10( ),12( )-octadecadienoate. In this chromatogram, peaks 2 and 4 are more abundant than ordinarily encountered retention times may vary (but not the order of elution) depending on the type of silica HPLC column. (B) CP-HPLC of peak 1 from A. The 13(R)-stereoisomer elutes before the 13(S)-stereoisomer. Elution times may vary. (C) CP-HPLC of peak 3 from A. The 9(S)-stereoisomer elutes before the 9(R)-stereoisomer. Elution times may vary.

Fig. 1 HPLC of free fatty acids. Column SUPELCOSIL LC 18. 25 cm X 4.6-mm ID. (5fi) mobile phase tetrahydrofuran/acetonitrile/0.1% phosphoric acid, pH 2.2 (21.6 50.4 28.0) flow rate 1.5 ml/min temperature 35°C detection at 220 nm sample concentration 1-2 mg/ml per component. 16 1 (cis) = cis-9-hexadecenoic acid (cis-palmitoleic acid) 16 1 (trans) = trans-9-hexadecenoic acid (trans-palmitoleic acid) 18 0 = octadecanoic acid (stearic acid) 18 1 (cis) = cw-9-octadecenoic acid (oleic acid) 18 1 (trans) = trans-9-octadecenoic acid (elaidic acid) 18 2 (cis) = cis-9-cis-12-ctadecadienoic acid (linoleic acid) 18 2 (trans) = trans-9-trans-12-octadecadienoic acid (linolelaidic acid) 18 3 (cis) = cis-9-cis-2-cis-15-octadecatrienoic acid (linolenic acid).

Linoleic acid 18 2 cis, cis-9,12-octadecadienoic acid Grape seed oil... 

Carotene, alone and conjugated with linoleic acid (CLA), octadecadienoic acid... 

Linoleic acid cis-9, cis-12-Octadecadienoic acid 18 Com oil, animal tissue, bacteria... 

Important essential fatty acids in the diet are linoleic acid (cis,cis-9,12-octadecadienoic acid, 18 2d9,12) and a-linolenic acid (all-cis-9,12,15-octadecatrienoic acid 18 3d9,12,15). The numbering in this conventional system begins with the carboxyl group. The "short hand," for example 18 2d9,12, indicates 18 carbon atoms, with two double bonds located between carbon atoms 9 and 10 and 12 and 13. There is an alternative system of numbering in which fatty acids are numbered from the methyl (or a>) terminal. In this case, linoleic acid is designated a>-6,9-octadecadienoic acid (18 2ft)6), and a-linolenic acid is o>-3,6,9-octadecatrienoic acid (18 3ft)3). This serves to designate two unsaturated fatty acid families, the ft)6 and the a families. 

CLA refers to a mixture of positional and geometric isomers of linoleic acid (cis-9, cis-12 octadecadienoic acid) with a conjugated double bond system. The structure of two CLA isomers is contrasted with linoleic and vaccenic acids in Figure 3.1. The presence of CLA isomers in ruminant fat is related to the biohydrogenation of polyunsaturated fatty acids (PUFAs) in the rumen. Ruminant fats are relatively more saturated than most plant oils and this is also a consequence of biohydrogenation of dietary PUFAs by rumen bacteria. Increases in saturated fatty acids are considered undesirable, but consumption of CLA has been shown to be associated with many health benefits, and food products derived from ruminants are the major dietary source of CLA for humans. The interest in health benefits of CLA has its genesis in the research by Pariza and associates who first demonstrated that... 

Conjugated linoleic acid (CLA) is a generic name for a mixture of positional and geometric isomers of linoleic acid (9c, 12c-octadecadienoic acid, 08 2) with conjugated double bonds at 7 and 9, 8 and 10, 9 and 11,10 and 12,11 and 13, or 12 and 14 positions. This fatty acid, carried out by rumen bacteria in the ruminal process, arises along a stepped pathway and ends with the full saturation of linoleic acid into stearic acid. These naturally occurring groups of dienoic derivatives of linoleic acid (LA) are incorporated into the fat in beef and the milk of ruminants before the saturation process has been completed. Food products from ruminants, particularly... 

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