title: Nonenzymatic isomerization of 9-cis-retinoic acid catalyzed by sulfhydryl compounds.
abstract: Certain thiol-containing compounds catalyze, in a chemical reaction, the isomerization of 9-cis-retinoic acid to a mixture of all-trans-retinoic acid, 9-cis-retinoic acid, 13-cis-retinoic acid, and 9,13-dicis-retinoic acid. In the presence of such catalysts, all-trans-retinoic acid gives rise to the same mixture. Reactions approaching equilibrium contain more all-trans-retinoic acid than either of the other isomers. Small molecules effective as catalysts are mercaptoethanol, L-cysteine methyl ester, glutathione, and N-acetyl-L-cysteine. Apoferritin (a thiol-containing protein), native microsomes, and, to a lesser extent, boiled microsomes catalyze the reaction. In intact cells, these interconversions also occur in a process inhibited by a sulfhydryl-specific reagent. The thiol-catalyzed isomerization of 9-cis-retinoic acid may be relevant in the biological activity of this compound.
authors.affiliation: Southern Research Institute, Birmingham, AL 35255-5305, USA.
authors.forename: T W
authors.initials: TW
authors.lastname: Shih
authors.forename: T H
authors.initials: TH
authors.lastname: Lin
authors.forename: Y F
authors.initials: YF
authors.lastname: Shealy
authors.forename: D L
authors.initials: DL
authors.lastname: Hill
mesh_terms: D000077556:Alitretinoin; D000818:Animals; D002460:Cell Line; D006801:Humans; D066298:In Vitro Techniques; D015474:Isotretinoin / Q000737:chemistry; D051379:Mice; D008862:Microsomes, Liver / Q000378:metabolism; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D014212:Tretinoin / Q000031:analogs & derivatives / Q000737:chemistry* / Q000378:metabolism
chemical_list: D013438:Sulfhydryl Compounds; D000077556:Alitretinoin; C105492:9,13-retinoic acid; D014212:Tretinoin; D015474:Isotretinoin