A New Natural Quaternary Indole Alkaloid Isolated from Tabernaemontana laeta Mart. (Apocynaceae)

Abstract

A new natural quaternary alkaloid, Nb-methylvoachalotine (1), was obtained from the root bark of Tabernaemontana laeta together with three dimeric indole alkaloids, conodurine (2), voacamine (3) and tabemamine (4), and the monomeric indole alkaloids 19S-heyneanine (5), coronaridine (6) and voacangine (7). The known triterpenes α-amyrin acetate, β-amyrin acetate, lupeol acetate and taraxasterol acetate and the phytosterol β-sitosterol and its 3-O-β-D-glucoside were also identified. The structures of the compounds were elucidated based on spectroscopic studies.