PubAg

Main content area

Tropolone Ring Construction in the Biosynthesis of Rubrolone B, a Cationic Tropolone Alkaloid from Endophytic Streptomyces

Author:
Yan, Yijun, Ma, Ya-Tuan, Yang, Jing, Horsman, Geoff P., Luo, Dan, Ji, Xu, Huang, Sheng-Xiong
Source:
Organic letters 2016 v.18 no.6 pp. 1254-1257
ISSN:
1523-7052
Subject:
Streptomyces, alkaloids, biosynthesis, carbon, chemical reactions, endophytes, fungi, moieties, secondary metabolites, stable isotopes, tropolone, zwitterions
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 [¹³C]-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.
Agid:
5792486