title: Studies on the biosynthesis of the alpha-glucosidase inhibitor acarbose: valienamine, a m-C7N unit not derived from the shikimate pathway.
abstract: Feeding experiments with Actinoplanes sp. SN223/29 showed that 3-amino-5-hydroxy-[7-13C]benzoic acid is not incorporated into acarbose (I). The valienamine moiety of I is thus not derived in the same way, from the shikimate pathway, as the m-C7N units in the ansamycin, mitomycin and ansamitocin antibiotics. Feeding experiments with [U-13C3]-glycerol followed by analysis of I by multiple quantum NMR spectroscopy support this conclusion and point to formation of the valienamine moiety by cyclization of a heptulose phosphate which arises from a triose phosphate via successive transfer of two 2-carbon fragments by transketolase, as proposed by Pape and co-workers.
authors.forename: U
authors.initials: U
authors.lastname: Degwert
authors.forename: R
authors.initials: R
authors.lastname: van Hülst
authors.forename: H
authors.initials: H
authors.lastname: Pape
authors.forename: R E
authors.initials: RE
authors.lastname: Herrold
authors.forename: J M
authors.initials: JM
authors.lastname: Beale
authors.forename: P J
authors.initials: PJ
authors.lastname: Keller
authors.forename: J P
authors.initials: JP
authors.lastname: Lee
authors.forename: H G
authors.initials: HG
authors.lastname: Floss
mesh_terms: D020909:Acarbose; D000192:Actinomycetales / Q000378:metabolism; D055598:Chemical Phenomena; D002621:Chemistry; D053138:Cyclohexenes; D005990:Glycerol / Q000378:metabolism; D065089:Glycoside Hydrolase Inhibitors; D006595:Hexosamines / Q000096:biosynthesis*; D009682:Magnetic Resonance Spectroscopy; D012765:Shikimic Acid / Q000378:metabolism*; D014312:Trisaccharides / Q000096:biosynthesis*
chemical_list: D053138:Cyclohexenes; D065089:Glycoside Hydrolase Inhibitors; D006595:Hexosamines; D014312:Trisaccharides; D012765:Shikimic Acid; C030791:valienamine; D005990:Glycerol; D020909:Acarbose