scholarly journals The hydrogenation of γ-linolenic acid by pure cultures of two rumen bacteria

1983 ◽  
Vol 216 (2) ◽  
pp. 519-522 ◽  
Author(s):  
P Kemp ◽  
D J Lander

Two species of rumen bacteria that have been previously shown to partially hydrogenate alpha-linolenic acid have been examined for their ability to hydrogenate gamma-linolenic acid. Free gamma-linolenic acid is hydrogenated in vitro to stearic acid by a rumen Fusocillus sp. (N.C.I.B. 11026), but only to cis, trans-octadec-6,11-enoic acid by a Butyrivibrio sp. The sequential hydrogenations are preceded by a delta 12-cis-delta 11-trans isomerization identical with that observed in the hydrogenation of alpha-linolenic acid and linoleic acid.

1984 ◽  
Vol 52 (1) ◽  
pp. 171-177 ◽  
Author(s):  
Patrick Kemp ◽  
David J. Lander ◽  
R. T. Holman

1. The hydrogenation of all the methylene-interrupted cis, cis-octadecadienoic acids was examined using pure cultures of six rumen bacteria able to hydrogenate linoleic acid to stearic acid or its immediate precursor, trans-1 1-octadecenoic acid, after first conjugating the linoleic acid to cis,truns-9, 1 1-octadecadienoic acid.2. Only the Δ 14-cis, 17-cis-isomer was not hydrogenated by at least one of the bacteria and no evidence was found that conjugation was necessary before hydrogenation except for the Δ 2-cis,5-cis- and Δ 9-cis, 12-cis-isomers. Several isomers were hydrogenated to an extent close to that achieved with linoleic acid (Δ 9-cis, 124s).3. Those bacteria only able to hydrogenate linoleic to trans-1 1-octadecenoic acid gave only octadecenoic acid products and those bacteria able to hydrogenate linoleic acid to stearic gave variable yields of octadecenoic acids and stearic acid except with the isomers Δ 12-cis, 15-cis and Δ 13-cis, Idcis when only octadecenoic acids were detected.4. At the substrate levels used (20 μg/ml), both inhibition and stimulation of growth were found but no common pattern emerged, nor was the growth consistently related to the extent of hydrogenation.


2021 ◽  
Author(s):  
Masoomeh Zeinalzadegan ◽  
Maryam Nejadmansouri ◽  
Mohammad-Taghi Golmakani ◽  
Gholam Reza Mesbahi ◽  
David Julian McClements ◽  
...  

1990 ◽  
Vol 28 (18) ◽  
pp. 69-70

Epogam capsules (Scotia) contain oil from the seed of the evening primrose which is rich in the essential fatty acid linoleic acid and its metabolite gamolenic (gamma-linolenic) acid. Epogam is licensed for use to relieve symptoms in atopic eczema, and is claimed to act at a fundamental metabolic level in this disease. Conventional treatment of eczema is often unsatisfactory, and any claim of an advance must be taken seriously. How well founded are the claims made for Epogam?


1992 ◽  
Vol 285 (2) ◽  
pp. 557-562 ◽  
Author(s):  
T Liang ◽  
S Liao

Human or rat microsomal 5 alpha-reductase activity, as measured by enzymic conversion of testosterone into 5 alpha-dihydrotestosterone or by binding of a competitive inhibitor, [3H]17 beta-NN-diethulcarbamoyl-4-methyl-4-aza-5 alpha-androstan-3-one ([3H]4-MA) to the reductase, is inhibited by low concentrations (less than 10 microM) of certain polyunsaturated fatty acids. The relative inhibitory potencies of unsaturated fatty acids are, in decreasing order: gamma-linolenic acid greater than cis-4,7,10,13,16,19-docosahexaenoic acid = cis-6,9,12,15-octatetraenoic acid = arachidonic acid = alpha-linolenic acid greater than linoleic acid greater than palmitoleic acid greater than oleic acid greater than myristoleic acid. Other unsaturated fatty acids such as undecylenic acid, erucic acid and nervonic acid, are inactive. The methyl esters and alcohol analogues of these compounds, glycerols, phospholipids, saturated fatty acids, retinoids and carotenes were inactive even at 0.2 mM. The results of the binding assay and the enzymic assay correlated well except for elaidic acid and linolelaidic acid, the trans isomers of oleic acid and linoleic acid respectively, which were much less active than their cis isomers in the binding assay but were as potent in the enzymic assay. gamma-Linolenic acid had no effect on the activities of two other rat liver microsomal enzymes: NADH:menadione reductase and glucuronosyl transferase. gamma-Linolenic acid, the most potent inhibitor tested, decreased the Vmax. and increased Km values of substrates, NADPH and testosterone, and promoted dissociation of [3H]4-MA from the microsomal reductase. gamma-Linolenic acid, but not the corresponding saturated fatty acid (stearic acid), inhibited the 5 alpha-reductase activity, but not the 17 beta-dehydrogenase activity, of human prostate cancer cells in culture. These results suggest that unsaturated fatty acids may play an important role in regulating androgen action in target cells.


2012 ◽  
Vol 66 (2) ◽  
pp. 207-209 ◽  
Author(s):  
Boris Pejin ◽  
Ljubodrag Vujisic ◽  
Marko Sabovljevic ◽  
Vele Tesevic ◽  
Vlatka Vajs

The fatty acid composition of the moss species Atrichum undulatum (Hedw.) P. Beauv. (Polytrichaceae) and Hypnum andoi A.J.E. Sm. (Hypnaceae) collected in winter time were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) as a contribution to their chemistry. Eight fatty acids were identified in the chloroform/methanol extract 1:1 of A. undulatum (linoleic acid 26.80%, palmitic acid 22.17%, ?-linolenic acid 20.50%, oleic acid 18.49%, arachidonic acid 6.21%, stearic acid 3.34%, cis-5,8,11,14,17-eicosapentaenoic acid 1.52% and behenic acid 1.01%), while six fatty acids were found in the same type of extract of H. andoi (palmitic acid 63.48%, erucic acid 12.38%, stearic acid 8.08%, behenic acid 6.26%, lignoceric acid 5.16% and arachidic acid 4.64%). According to this study, the moss A. undulatum can be considered as a good source of both essential fatty acids for humans (linoleic acid and ?-linolenic acid) during the winter.


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