Ochrocephalamines B–D, Three Alkaloids from Oxytropis ochrocephala Bunge

Ochrocephalamines B-D (1-3), composed of fused quinolizidine and octahydroquinoline rings, were isolated from Oxytropis ochrocephala Bunge. Ochrocephalamine B (1) has a unique bridged tetracyclic ring skeleton fused with a lactam ring. The structures of 1-3 were elucidated using spectroscopic and computational approaches. Ochrocephalamine C (2) and D (3) demonstrated potent anti-HBV activities and are more potent against the secretion of HBeAg than that of HBsAg.