title: Isolation and identification of 5, 6-epoxyretinoic acid: a biologically active metabolite of retinoic acid.
abstract: A highly biologically active metabolite of retinoic acid (8III) has been isolated in pure form from intestinal mucosa of vitamin A deficient rats given [3H]retinoic acid. This metabolite has been positively identified as 5, 6-epoxyretinoic acid based on the ultraviolet absorption spectrum and mass spectrum of its methylated derivative. This identification was confirmed by cochromatography of the methylated metabolite and synthetic methyl 5, 6-epoxyretinoate on reverse-phase and straight-phase high-pressure liquid chromatography. The 5, 6-epoxyretinoic acid is a true in vivo generated metabolite of retinoic acid and not an artifact of the isolation procedure. In addition, 5, 8-oxyretinoic acid previously isolated in this laboratory from intestinal mucosa was probably generated from 5, 6-epoxyretinoic acid by the acidic conditions used in the extraction and isolation of the 5, 8-oxyretinoic acid.
mesh_terms: D000818:Animals; D004852:Epoxy Compounds / Q000302:isolation & purification; D007413:Intestinal Mucosa / Q000378:metabolism; D008297:Male; D013058:Mass Spectrometry; D051381:Rats; D013056:Spectrophotometry, Ultraviolet; D014212:Tretinoin / Q000031:analogs & derivatives* / Q000302:isolation & purification / Q000378:metabolism; D014801:Vitamin A / Q000031:analogs & derivatives*; D014802:Vitamin A Deficiency / Q000378:metabolism
chemical_list: D004852:Epoxy Compounds; D014801:Vitamin A; D014212:Tretinoin