Nonpolar Products Research Articles

A study of the products of the autooxidation of vitamin D I. Nonpolar products of the oxidative degradation of vitamin D2

It has been found that in the autooxidation of vitamin D2 in an aqueous medium substances of peroxide and carbonyl nature are formed. The main nonpolar products are the C21 aldehyde (Heilbron) and 7a-methyl-1-(1′,4′,6′-trimethylhex-2′-en-1′-yl)hydrind-3a-ene-3a-carbaldehyde.

Origin of some derivatives of retinoic acid found in rat bile

After the intraportal injection of retinoic acid-15-(14)C into rats, all-trans methyl retinoate, a cis isomer of methyl retinoate, retinoyl beta-glucurono-gamma-lactone, retinoic acid, and retinoyl beta-glucuronide were isolated from methanol extracts of rat bile by chromatography on anion-exchange resin and silicic acid columns and characterized on thin-layer plates of Silica Gel G. On the other hand, when bile was extracted with n-butanol or analyzed directly by thin-layer chromatography, only retinoyl beta-glucuronide and a very small amount of retinoic acid could be detected. Butanol extracts of the liver and the intestine, however, still contained a small radioactive nonpolar fraction. When retinoyl beta-glucuronide was incubated with an anion-exchange resin in the presence of methanol, several nonpolar products appeared. Apparently the methyl retinoate, retinoyl beta-glucurono-gamma-lactone, and most of the retinoic acid previously found in bile after retinoic acid administration are produced from retinoyl beta-glucuronide during the isolation procedure.