Synthesis and Cytotoxicity of Indole Derivatives of Betulin, Erythrodiol, and Uvaol

Abstract

2,3-Indolotriterpenic alcohols have been synthesized for the first time by successive modification of 3-oxo triterpenic acids (Fisher reaction, reduction of С17-СOOH, cyanoethylation) and characterized by physicochemical methods of analysis. It has been found that 2,3-indolouvaol and 2,3-indolo-28-cyanoethoxybetulin exhibit antitumor activity in vitro toward NCI-H522 lung cancer (–12.65%) and COLO 205 colon cancer cells (–42.78%), respectively. The activity of 2,3-indolooleanolic and 2,3-indolobetulinic acids toward 19 and 9 cell lines of six and four human cancers, respectively, has been revealed. Indole-fused triterpenoids have been shown to hold promise as objects in the search for novel antitumor agents.