Unusual Sesquiterpenes from Streptomyces olindensis DAUFPE 5622

J Nat Prod. 2024 Mar 22;87(3):491-500. doi: 10.1021/acs.jnatprod.3c00752. Epub 2024 Feb 29.

Abstract

In nature, the vast majority of sesquiterpenes are produced by type I mechanisms, and glycosylated sesquiterpenes are rare in actinobacteria. Streptomyces olindensis DAUFPE 5622 produces the sesquiterpenes olindenones A-G, a new class of rearranged drimane sesquiterpenes. Olindenones B-D are oxygenated derivatives of olindenone A, while olindenones E-G are analogs glycosylated with dideoxysugars. 13C-isotope labeling studies demonstrated olindenone A biosynthesis occurs via the methylerythritol phosphate (MEP) pathway and suggested the rearrangement is only partially concerted. Based on the structures, one potential mechanism of olindenone A formation proceeds by cyclization of the linear terpenoid precursor, likely occurring via a terpene cyclase-mediated type II mechanism whereby the terminal alkene of the precursor is protonated, triggering carbocation-driven cyclization followed by rearrangement. Diphosphate hydrolysis may occur either before or after cyclization. Although a biosynthetic route is proposed, the terpene cyclase gene responsible for producing olindenones currently remains unidentified.

MeSH terms

  • Cyclization
  • Sesquiterpenes* / chemistry
  • Streptomyces* / metabolism
  • Terpenes / metabolism

Substances

  • Sesquiterpenes
  • Terpenes

Supplementary concepts

  • Streptomyces olindensis