Synthesis and Structure Revision of Naturally Occurring Homoisoflavane (+)-Dracaeconolide B

J Nat Prod. 2023 Jan 27;86(1):149-156. doi: 10.1021/acs.jnatprod.2c00859. Epub 2022 Dec 21.

Abstract

Dracaeconolide B (1), a naturally occurring homoisoflavane, was isolated from the red resin of Dracaena cochinchinensis. Efforts have been made to elucidate the exact structure of compound 1 since it was confirmed that dracaeconolide B did not contain a 7-hydroxy-5,8-dimethoxy moiety. The structure of dracaeconolide B was revised by synthesis of three homoisoflavanes containing a 5,6,7-trioxygenated moiety each and analysis by NMR spectroscopy. The revised structure of dracaeconolide B was proposed as 3-(4-hydroxybenzyl)-7-hydroxy-5,6-dimethoxychromane. Noyori's Ru-catalyzed asymmetric transfer hydrogenation was used to synthesize (+)-dracaeconolide B. The absolute configuration of the compound was revised to S based on the results obtained by the electronic circular dichroism calculation. We examined the antiangiogenic activity of (S)- and (R)-dracaeconolide B and of synthetic 5,6,7- and 5,7,8-trioxygenated homoisoflavanes. The results can potentially help in the synthesis of related natural products and support drug discovery to treat neovascular eye diseases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Dracaena* / chemistry
  • Magnetic Resonance Spectroscopy
  • Molecular Structure
  • Plant Extracts / chemistry
  • Resins, Plant / chemistry
  • Stereoisomerism

Substances

  • Plant Extracts
  • Resins, Plant
  • dracaeconolide B

Supplementary concepts

  • Dracaena cochinchinensis