Oleic, linoleic and linolenic acids were autoxidized more rapidly than their corresponding methyl esters. Addition of stearic acid accelerated the rate of autoxidation of methyl linoleate and the decomposition of methyl linoleate hydroperoxides. Therefore, the higher oxidative rate of FFA's than their methyl esters could be due to the catalytic effect of the carboxyl groups on the formation of free radicals by the decomposition of hydroperoxides. Addition of stearic acid also accelerated the oxidative rate of soybean oil. This result suggests that particular attention should be paid to the FFA content that affects the oxidative stability of oils.

Open-tubular gas chromatographic analysis of fatty acids in the lipids from the seeds of 20 species of Gymnospermae showed that they all contained nonmethylene-interrupted polyenoic (NMIP) acids as minor components and palmitic, oleie, linoleic and ~-linolenic acids as major components. The NMIP acids have an additional 5,6-ethylerdc bond in ordinary plant unsaturated fatty acids and the following C 2 elongation acids: eis-5, cis-9-octadeeadienoic acid (5,9-18:2) (I); 5,9,12-18:3 (II); 5,9,12,[15][16][17][18] 5,[11][12][13][14][15][16][17][18][19][20] 5,11,[14][15][16][17][18][19][20] and 5,11,14,[17][18][19][20]. The main NMIP acids found in neutral lipids are I in two species of Taxus, II in seven species of Pinaceae, III in two species of Podocarpaceae, Torreya nucifera, Cycas revoluta, and Ginkgo biloba, and III and IV in each of three species of Taxodiaceae, and Cupressaceae. The polar lipids constitute the minor fraction of seed lipids in general. The content and composition of NMIP acids in these lipids differ considerably fromthose in neutral lipids. Analysis of the partial cleavage products of triacylglycerois showed that the NMIP acids distribute mainly in the 1,3-position.Lipids 17: 716-723, 1982.

A novel reagent, [(oxido)phenyl(trifluoromethyl)-λ 4 -sulfanylidene]dimethylammonium tetrafluoroborate has been developed for the electrophilic trifluoromethylation of carbon nucleophiles. The reagent was designed as a trifluorinated version of a Johnson-type methyl-transfer reagent. The first

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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.