Two new quaternary alkaloids and anti-hepatitis B virus active constituents from Corydalis saxicola.

Two new quaternary isoquinoline alkaloids, saxicolalines A (1) and N-methylnarceimicine (2), together with sixteen known alkaloids (3 - 18) were isolated from Corydalis saxicola Bunting. The structures of saxicolalines A (1) and N-methylnarceimicine (2) were established based on spectral methods including 1D, 2D NMR (COSY, HMQC, HMBC) and HR-ESI-MS. The anti-HBV activities of ten main alkaloids were evaluated. Among the tested compounds, dihydrochelerythrine (8) exhibited the most potent activity against HBsAg and HBeAg secretions with IC50 < 0.05 microM, SI > 3.5, respectively.