Preparation, properties and metabolism of 5,6-monoepoxyretinoic acid

Abstract

Methyl retinoate has been converted into methyl 5, 6-monoepoxyretinoate by reaction with monoperphthalic acid. The epoxy acid ester on alkaline hydrolysis gave 5, 6-monoepoxyretinoic acid. Treatment of the 5, 6-monoepoxy compounds with ethanolic hydrochloric acid gave the corresponding 5, 8-epoxy (furanoid) compounds. With lithium aluminium hydride, the acid and the ester groups were selectively reduced to primary alcohols. Administration of methyl 5, 6-monoepoxyretinoate intraperitoneally and subcutaneously had good growth response in vitamin A-deficient rats. 5, 6-Monoepoxyretinoic acid, when given intraperitoneally as the sodium salt, was 157 percent as active as all-trans-retinyl acetate. Methyl 5, 6-monoepoxyretinoate was hydrolysed to the epoxy acid by rat-liver homogenate. It had 35 percent of the biological activity of all-trans-retinyl acetate in the rat when given orally.