Alkaloids from Houttuyniae Cordata

The crude extract of Houttuyniae cordata showed potent anti-platelet and cytotoxic activities. The constituents of this plant, two pyridine alkaloids 1 and 2, along with three aporphine related alkaloids, cepharanone B (3), cepharadione B (4) and 7-choloro-6-demethyl cepharadione B (5) were characterized by spectral methods. Among them, long chain substituted pyridine alkaloids 1 and 2 are rare in nature, and the 7-choloro-6-demethyl cepharadione B (5) is isolated for the first time.