Thin-layer chromatography of homologues and vinylogues of higher fatty aldehydes, dimethyl acetals, and 2,4-dinitrophenylhydrazones

Incorporation of [1-14C]octadecanol into the lipids of Leishmania donovani

After incubation of stationary phase Leishmania donovani with [1-14C]octadecanol, about 70% of the precursor was taken up within 3 hr. Wax esters and acyl moieties of glycerolipids contained most of the 14C-activity from 3 to 6 hr, because octadecanol was partly oxidized to stearate. Ether moieties were only weakly labeled. After 40 hr, 1-0-alkyl and 1-0-alk-1'-enyl diacylglycerols as well as 1-0-alkyl and 1-0-alk-1'-enyl-2-acyl-sn-glycero-3-phosphoethanolamines contained nearly all of the radioactivity. Most of the label in the neutral ether lipids was located in the alkyl ether side chain, whereas, in the phosphatidylethanolamine fraction, most of the label was found in the alkenyl ether side chain. Administration of 1-0-[1-14C]hexadecyl glycerol resulted in rapid labeling of the vinyl ether side chain of phosphatidylethanolamine plasmalogen (1 hr) increasing further at 2.5 hr. Most of the radioactivity in the alkoxy diacylglycerols was found in the 1-0-alkyl moiety.

The influence of maize oil on the fatty acid composition of tissues of calves with and without vitamin E

1. Fatty acid levels were studied in the tissues of 1-week-old calves receiving maize oil (in filled milk) with and without supplementary α-tocopherol. The calves that were not given vitamin E developed muscular dystrophy.

2. Decreased amounts of linoleic acid and increased amounts of arachidonic acid were found in nearly all the lipid fractions of skeletal muscles, hearts, livers and kidneys of vitamin E-deficient calves. The concentration of the polyunsaturated fatty acids beyond arachidonic acid remained about the same in both groups. There was a significant decrease of 20:2Ω6 fatty acid in the phosphatidy1 choline, phosphatidy1 ethanolamine and free fatty acid fractions in the livers and kidneys of vitamin E-deficient calves.

3. It is suggested that vitamin E has an inhibitory effect on the desaturating but not on the chain-elongation enzymes of microsomes in the liver and kidney.

4. Maize-oil feeding had only a slight effect on erythrocyte fatty acid composition, and the erythrocyte haemolysis test was negative even in the vitamin E-deficient animals.