Indole alkaloids from Gelsemium elegans

Phytochemistry. 2019 Jun:162:232-240. doi: 10.1016/j.phytochem.2019.03.016. Epub 2019 Apr 4.

Abstract

Five previously undescribed monoterpenoid indole alkaloids were isolated from the roots of Gelsemium elegans. Their structures with absolute configurations were elucidated by HRESIMS, X-ray diffraction, ECD spectra, and molecular modeling. 19,20-Epoxyhumantenine is a humantenine-type alkaloid with an epoxypropyl group at the C-20 position, (4R)-19-oxo-gelsevirine N4-oxide is a gelsemine-related alkaloid, and gelsedethenine is a gelsedine-type alkaloid with a butenyl group at the C-20 position. Moreover, 10,11-dimethoxy-N1-demethoxy-gelsemamide is an open-loop indole alkaloid and 11-demethoxy-gelsemazonamide is an aromatic azo-linked dimeric indole alkaloid. Among the five alkaloids, (4R)-19-oxo-gelsevirine N4-oxide and 10,11-dimethoxy-N1-demethoxy-gelsemamide exhibited significant inhibitory effects on nitric oxide production in lipopolysaccharide-induced RAW 264.7 macrophage cells, with IC50 values of 6.18 ± 1.07 and 12.2 ± 1.02 μM, respectively.

Keywords: Gelsemiaceae; Gelsemium elegans; Indole alkaloid; Nitric oxide.

MeSH terms

  • Animals
  • Gelsemium / chemistry*
  • Indole Alkaloids / chemistry*
  • Indole Alkaloids / pharmacology
  • Inhibitory Concentration 50
  • Mice
  • Models, Molecular
  • Molecular Conformation
  • Nitric Oxide / antagonists & inhibitors
  • RAW 264.7 Cells

Substances

  • Indole Alkaloids
  • Nitric Oxide