A Cytotoxic Indole Characterized by Incorporation of a Unique Carbon–Nitrogen Skeleton and Two Pentacyclic Corynanthean Alkaloids Incorporating a Substituted Tetrahydrofuranone Ring from Kopsia arborea
Document Type
Article
Publication Date
1-1-2019
Abstract
Three new alkaloids were isolated from the bark extract of the Malayan Kopsia arborea, viz., arbophyllidine (1), an unusual pentacyclic, monoterpenoid indole characterized by an absence of oxygen atoms and incorporating a new carbon-nitrogen skeleton, and arbophyllinines A (2) and B (3), two pentacyclic corynanthean alkaloids incorporating a hydroxyethyl-substituted tetrahydrofuranone ring. The structures of the alkaloids were deduced based on analysis of the MS and NMR data and confirmed by X-ray diffraction analyses. The absolute configuration of arbophyllidine (1) was established based on experimental and calculated ECD data, while that of arbophyllinine A was based on X-ray diffraction analysis (Cu Kα). A reasonable biosynthetic route to arbophyllidine (1) from a pericine precursor is presented. Arbophyllidine (1) showed pronounced in vitro growth inhibitory activity against the HT-29 human cancer cell line with IC50 6.2 μM. © 2019 American Chemical Society and American Society of Pharmacognosy.
Keywords
Alkaloids, Indole Alkaloids, Bisindole alkaloids
Divisions
CHEMISTRY,InstituteofBiologicalSciences
Funders
University of Malaya (UMRG, RP036-17AFR)
Publication Title
Journal of Natural Products
Volume
82
Issue
7
Publisher
American Chemical Society