Occurrence of mixtures of geometrical isomers of conjugated octadecatrienoic acids in some seed oils: Analysis by open‐tubular gas liquid chromatography and high performance liquid chromatography

Abstract

Analytical methods to obtain the detailed compositions of the fatty acids in oils containing more than one conjugated octadecatrienoic acid by open‐tubular gas liquid chromatography (GLC) and by reversed‐phase high performance liquid chromatography (HPLC) were established. Effective GLC separations ofcis,trans,trans‐9,11,13‐octadecatrienoic acid (ctt‐9,11,13–18∶3),ctc‐9,11,13–18∶3,ttc‐9,11,13–18∶3,ttt‐9,11,13–18∶3,ttc‐8,10,12–18∶3, andttt‐8,10,12–18∶3 were obtained with an opentubular column coated with the nonpolar liquid phase OV‐1 using an instrument having all‐glass carrier gas pathways. The HPLC method also gave satisfactory separations for the isomeric conjugated octadecatrienoates on the basis of number of thecis andtrans double bonds. Two or three minor conjugated trienoic acids were found along with the principal conjugated trienoic acid in tung oil, and seed oils of cherry,Prunus sp., Momordica charantia, Trichosanthes anguina, Punica granatum, Catalpa ovata, andCalendula officinalis. The mechanism for the formation of the conjugated trienoic acid mixtures in the seed oils is discussed. TheC. ovata seed oil also containedct andtt‐9,12‐octadecadienoic acids. Thett isomer is presumed to be a precursor ofttc‐9,11,13–18∶3, the main conjugated trienoic acid in this oil.

Dietary seed oil rich in conjugated linolenic acid from bitter melon inhibits azoxymethane‐induced rat colon carcinogenesis through elevation of colonic PPARγ expression and alteration of lipid composition

“…BMO was extracted from seed of bitter melon according to methods described previously. 23 The fatty acid profile of the total lipids in BMO was generally in harmony with that described in other report, 29 with very high level (60.2%) of 9c,11t,13t-18:3 and a small amount of other CLN isomers, namely, 9c,11t,13c-18:3 (0.6%) and 9t,11t,13t-18:3 (0.3%). These lipids also contained high amount (27.2%) of 18:0 and modest amount of 18:1n-9 (5.9%) and 18:2n-6 (3.8%).…”

Fractionation and identification of 9c, 11t, 13t-conjugated linolenic acid as an activator of PPARα in bitter gourd (Momordica charantia L.)

“…9c, 11t, 13t-CLN has been reported to be a form of fatty acids distributed in bitter gourd and mainly in seeds [32,33].…”

Comparison of Separation of Seed Oil Triglycerides Containing Isomeric Conjugated Octadecatrienoic Acid Moieties by Reversed-Phase HPLC

“…According to literature data [24], this acid fraction in fatty acids composition is 42.25%, while the contents of other acids are as follows: linoleic (39.95%), oleic (7.71%), palmitic (2.77%), and stearic . Separation of TGs of Calendula officinalis seed oil.…”