title: Tropolone Ring Construction in the Biosynthesis of Rubrolone B, a Cationic Tropolone Alkaloid from Endophytic Streptomyces.
abstract: Rubrolones are tropolonoid natural products with a unique carbon skeleton. Extensive secondary metabolite analysis of the endophytic Streptomyces sp. KIB-H033 revealed a new class of rubrolone analogue possessing a rare benzoic acid-pyridine inner salt moiety. Precursor feeding with [(13)C]-acetate revealed a labeling pattern consistent with tropolone moiety construction via type-II PKS chemistry followed by complex oxidative rearrangements. This bacterial biosynthetic route represents a surprising departure from fungal tropolone assembly during stipitatic acid biosynthesis.
authors.affiliation: State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences , Kunming 650201, China.
authors.forename: Yijun
authors.initials: Y
authors.lastname: Yan
authors.affiliation: State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences , Kunming 650201, China.
authors.forename: Ya-Tuan
authors.initials: YT
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences , Kunming 650201, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Chemistry & Biochemistry, Wilfrid Laurier University , Waterloo, ON N2L 3C5, Canada.
authors.forename: Geoff P
authors.initials: GP
authors.lastname: Horsman
authors.affiliation: State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences , Kunming 650201, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Luo
authors.affiliation: State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences , Kunming 650201, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Ji
authors.affiliation: State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences , Kunming 650201, China.
authors.forename: Sheng-Xiong
authors.initials: SX
authors.lastname: Huang
mesh_terms: D000470:Alkaloids / Q000378:metabolism; D001688:Biological Products / Q000138:chemical synthesis* / Q000737:chemistry; D002412:Cations; D015394:Molecular Structure; D011725:Pyridines / Q000138:chemical synthesis* / Q000737:chemistry; D013302:Streptomyces / Q000737:chemistry*; D014334:Tropolone / Q000031:analogs & derivatives
chemical_list: D000470:Alkaloids; D001688:Biological Products; D002412:Cations; D011725:Pyridines; C019082:rubrolone; D014334:Tropolone