Criofolinine and vernavosine, new pentacyclic indole alkaloids incorporating pyrroloazepine and pyridopyrimidine moieties derived from a common yohimbine precursor

Org Lett. 2014 Dec 19;16(24):6330-3. doi: 10.1021/ol503072g. Epub 2014 Dec 2.

Abstract

Two new indole alkaloids characterized by previously unencountered natural product skeletons, viz., criofolinine (1), incorporating a pyrroloazepine motif within a pentacyclic ring system, and vernavosine (2, isolated as its ethyl ether derivative 3, which on hydrolysis regenerated the putative precursor alkaloid 2), incorporating a pyridopyrimidine moiety embedded within a pentacyclic carbon framework, were isolated from a Malayan Tabernaemontana species. The structures and absolute configuration of these alkaloids were determined on the basis of NMR and MS analysis and confirmed by X-ray diffraction analysis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Azepines / chemistry*
  • Indole Alkaloids / chemistry*
  • Indole Alkaloids / isolation & purification
  • Magnetic Resonance Spectroscopy
  • Molecular Structure
  • Plant Leaves
  • Pyrimidines / chemistry*
  • Stereoisomerism
  • Tabernaemontana / chemistry*
  • X-Ray Diffraction
  • Yohimbine / chemistry*

Substances

  • Azepines
  • Indole Alkaloids
  • Pyrimidines
  • criofolinine
  • vernavosine
  • Yohimbine