Vobatensines A-F, Cytotoxic Iboga-Vobasine Bisindoles from Tabernaemontana corymbosa

  • J Nat Prod. 2016 Apr 22;79(4):1048-55. doi: 10.1021/acs.jnatprod.5b01117.
Dawn Su-Yin Sim  1 ,  Wuen-Yew Teoh  1 ,  Kae-Shin Sim  1 ,  Siew-Huah Lim  1 ,  Noel F Thomas  1 ,  Yun-Yee Low  1 ,  Toh-Seok Kam  1
Affiliations
  • 1. Department of Chemistry and ‡Institute of Biological Sciences, University of Malaya , 50603 Kuala Lumpur, Malaysia.
PMID: 26918761 DOI: 10.1021/acs.jnatprod.5b01117
Abstract

Six new bisindole Alkaloids of the iboga-vobasine type, vobatensines A-F (1-6), in addition to four known bisindoles (8-11), were isolated from a stem bark extract of a Malayan Tabernaemontana corymbosa. The structures of these Alkaloids were determined based on analysis of the spectroscopic data and in the case of vobatensines A (1), B (2), and 16'-decarbomethoxyvoacamine (8) also confirmed by partial syntheses. Nine of these Alkaloids (1-5, 8-11) showed pronounced in vitro growth inhibitory activity against human KB, PC-3, LNCaP, HCT 116, HT-29, MCF7, MDA-MB-231, and A549 Cancer cells.