Distribution, bioactive components and biological activities of Stemona species in Thailand

Abstract

Phytochemical investigations of Stemona species have revealed the presence of alkaloids, stilbenoids, tocopherols (chromenols), etc. Stemona alkaloids constitute a unique chemical feature of the Stemonaceae and cannot be detected so far in any other plant families. Their alkaloid structures are characterized by a pyrrolo[1,2-a]azepine core which can be classified into three types based on biosynthetic consideration i.e. stichoneurine-(tuberostemonine-), protostemonine- and croomine-types of alkaloids. Tuberosa group contains stichoneurine- and croomine-types, demonstrating antitussive activity, while non-tuberosa group contains protostemonine type alkaloid which promotes potent insecticidal activity. Biological testings showed that insecticide and antitussive activities of Stemona are depended on Stemona alkaloids while antifungal activity against plant-pathogenic fungi is depended on the presence of stilbenoids. Moreover, preliminary tests on anticancer and antioxidant activities of some Stemona species have also been reported.