title: Chemically unprecedented biocatalytic (AuaG) retro-[2,3]-Wittig rearrangement: a new insight into aurachin B biosynthesis.
abstract: AuaG is flavin-dependent monooxygenase responsible for the conversion of aurachin C to aurachin B, a reaction thought to resemble semipinacol migration of the farnesyl substituent. A study of the substrate tolerance of AuaG reveals that it has the peculiar ability to oxidise short-chain analogues of aurachin D. Unexpectedly, a novel retro-[2,3]-Wittig rearrangement was observed with an isoprenyl substrate analogue, thus leading to the 1,1-dimethylallyl ether. Additionally, we found that saturated-chain analogues of N-oxidised aurachin C were not transformed by the C3→C4 semipinacol reaction, as might have been expected for such substrates. Based on this and the unique retro-[2,3]-Wittig rearrangement, we discuss an alternative biosynthetic route for the conversion of aurachin C to aurachin B.
authors.affiliation: Department of Biotechnology, Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo (Japan).
authors.forename: Yohei
authors.initials: Y
authors.lastname: Katsuyama
authors.forename: Xu-Wen
authors.initials: XW
authors.lastname: Li
authors.forename: Rolf
authors.initials: R
authors.lastname: Müller
authors.forename: Bastien
authors.initials: B
authors.lastname: Nay
mesh_terms: D055162:Biocatalysis; D006899:Mixed Function Oxygenases / Q000235:genetics / Q000378:metabolism*; D010084:Oxidation-Reduction; D011804:Quinolines / Q000737:chemistry / Q000378:metabolism; D015363:Quinolones / Q000737:chemistry / Q000378:metabolism; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics; D013237:Stereoisomerism
chemical_list: D011804:Quinolines; D015363:Quinolones; D011994:Recombinant Proteins; C052095:aurachin B; C052097:aurachin D; D006899:Mixed Function Oxygenases
keywords: aurachins; biosynthesis; natural products; oxidative biocatalysis; quinolones; retro-[2,3]-Wittig rearrangement