First Discovery of Tylophora Alkaloids as HIV Inhibitors

A series of tylophora alkaloids and their derivatives (1–38) were synthesized and systematically bioassayed for their anti-HIV activity for the first time. The results revealed that most of these alkaloids possess good HIV inhibitory effect. Especially, compounds 1, 4 and 25 displayed low nanomolar levels of anti-HIV activity (inhibitory effect at 50 nM: 1: 71%; 4: 60%; 25: 64%), which is about similar to that of the first HIV inhibitor AZT (inhibitory effect at 50 nM: 70%) and slightly lower than that of the first HIV integrase inhibitor MK-0518 (inhibitory effect at 50 nM: 82%). Present studies provide fundamental support for the development of tylophora alkaloids as novel HIV inhibitors.