Alpha-glucosidase inhibitory, aromatase inhibitory, and antiplasmodial activities of a biflavonoid GB1 from Garcinia kola stem bark.

The biflavonoid, 3'',4',4''',5,5'',7,7''-heptahydroxy-3,8-biflavanone, known as GB1 (1), was isolated as a major constituent from Garcinia kola stem bark. GB1 (1) exhibited alpha-glucosidase and aromatase inhibitory activities, as well as antiplasmodial activity, but was not toxic against cell lines tested. GB1 (1) may be a potential dietary supplement or phytomedicine for the prevention of breast cancer and type 2 diabetes mellitus.