title: Prokaryotic triterpenoids. 3. The biosynthesis of 2 beta-methylhopanoids and 3 beta-methylhopanoids of Methylobacterium organophilum and Acetobacter pasteurianus ssp. pasteurianus.
abstract: The incorporation of L-[methyl-3H,14C]methionine or L-(methyl-2H3)methionine into 2 beta-methyldiplopterol of Methylobacterium organophilum and various 3 beta-methylhopanoids of Acetobacter pasteurianus ssp. pasteurianus showed that all three hydrogen atoms of the transferred methyl group are retained in the triterpenoids. These methylations are compatible with a methylation substrate such as a delta 2-hopanoid in the case of the 2 beta-methylhopanoid biosynthesis and of a delta 2-hopanoid or squalene in the case of the formation of 3 beta-methylhopanoids. The intervention of intermediates possessing an exomethylene group or a cyclopropane ring is excluded.
mesh_terms: D000091:Acetobacter / Q000378:metabolism*; D003903:Deuterium; D013058:Mass Spectrometry; D008745:Methylation; D008772:Methylococcaceae / Q000378:metabolism*; D014315:Triterpenes / Q000096:biosynthesis*
chemical_list: D014315:Triterpenes; D003903:Deuterium