Abstract
The present work has led to the isolation, from the leaves of Uncaria homomalla collected in Thailand, of four pentacyclic oxindole alkaloids, isopteropodine, pteropodine, speciophylline and uncarine F. All of these have been described in other species ofUncaria and Mitragyna.
Uncar ia species have been investigated and reported for their alkaloids since 1920's. (Kondo, Fukuda and Tomita, 1928). In Thailand, the leaves of Uncaria species are used as a ,kratomc (Leaves of Mitragyna spe cio s a) substitute Jirawongse, 1975). Many species of Uncaria were shown to contain the alkaloids as those in the closely related genus Mitragyna. No previous investigations of the alkaloids in the leaves of Uncaria homomalla Miq. has, however, been reported.
