PHYTENIC ACID - IDENTIFICATION OF 5 ISOMERS IN CHEMICAL AND BIOLOGICAL PRODUCTS OF PHYTOL

1. 1. Previous studies in the rat indicated that the olefinic acid phytenic acid is an intermediate in the conversion of phytol to phytanic acid. Since phytol is a trans-Δ2 structure, the phytenic acid product might be expected to retain the same configuration. This study was made to determine which isomers of phytenic acid are formed from phytol by chemical means and by metabolism in the rat. 2. 2. Chemical oxidation of phytol produced virtually only one phytenic acid isomer (trans-Δ2), but dehydrobromination of 3-bromophytanic acid produced 5 isomers. Likewise, the same 5 isomers were found in the intestinal lymph of rats -both conventional and germ-free - that had been fed phytol. Phytenic acid of the lymph was present largely in complex lipids. Saponification caused isomerization of added trans-2-phytenic acid (methyl ester); however, direct transmethylation (with methanol-H2SO4) did not cause appreciable isomerization. Using the latter method, all 5 isomers were found in the lymph in differing quantities, which indicates that they were all formed during the absorption of phytol. 3. 3. The individual isomers of phytenic acid were isolated by thin-layer chromatography and gas-liquid chromatography, and were identified by ultraviolet absorption spectroscopy, nuclear magnetic resonance spectroscopy, and mass spectroscopy before and after hydrogenation and oxidative cleavage, respectively. They proved to be the trans- and cis-Δ2, the trans- and cis-Δ3, and the 3-methylene compounds. © 1969.