(±)-Uncarilins A and B, Dimeric Isoechinulin-Type Alkaloids from Uncaria rhynchophylla

J Nat Prod. 2017 Apr 28;80(4):959-964. doi: 10.1021/acs.jnatprod.6b00938. Epub 2017 Feb 22.

Abstract

(±)-Uncarilins A and B (1a/1b and 2a/2b), two pairs of unusual dimeric isoechinulin-type enantiomers with a symmetric four-membered core, were isolated from Uncaria rhynchophylla driven by LCMS-IT-TOF analyses. Their structures were elucidated by extensive 1D and 2D NMR spectra, X-ray diffraction, and ECD spectroscopic data. (-)-Uncarilin B (2a) showed activities on MT1 and MT2 receptors with agonistic rates of 11.26% and 52.44% at a concentration of 0.25 mM.

MeSH terms

  • Drugs, Chinese Herbal / chemistry
  • Drugs, Chinese Herbal / isolation & purification*
  • Humans
  • Indole Alkaloids / chemistry
  • Indole Alkaloids / isolation & purification*
  • Indoles
  • Molecular Structure
  • Nuclear Magnetic Resonance, Biomolecular
  • Receptor, Melatonin, MT1 / agonists
  • Receptor, Melatonin, MT2 / agonists
  • Stereoisomerism
  • Uncaria / chemistry*

Substances

  • Drugs, Chinese Herbal
  • Indole Alkaloids
  • Indoles
  • Receptor, Melatonin, MT1
  • Receptor, Melatonin, MT2
  • isoechinulin A