Plant antitumor agents, 19. Novel triterpenes from Maprounea africana.
Four new pentacyclic triterpenes have been isolated from Maprounea africana. These triterpenes are members of the previously unknown urs-12-en-29-oic acid series. The structures of these compounds were deduced from spectral and chemical evidence. The parent compound, maprounic acid, was identified as 3B-hydroxyurs-12-en-29-oic acid. The remaining three triterpenes were identified as maprounic acid 3-p-hydroxybenzoate, 7 beta-hydroxymaprounic acid 3-p-hydroxybenzoate, and 2 alpha-hydroxymaprounic acid 2,3-bis-p-hydroxybenzoate. Of the four triterpenes, only the 7 beta-hydroxy derivative exhibited in vivo P-388 activity.
Acetylation↗