Alkaloids from Toddalia asiatica and their cytotoxic, antimicrobial and antifungal activities

Phytochemical investigation of the ethanol extract from the roots of Toddalia asiatica resulted in the isolation of eight new alkaloids, 8-methoxynorchelerythrine (1), 11-demethylrhoifoline B (2), 8-methoxynitidine (3), 8-acetylnorchelerythrine (4), 8,9,10,12-tetramethoxynorchelerythrine (5), isointegriamide (6), 1-demethyl dicentrinone (7), and 11-hydroxy-10-methoxy-(2,3)-methylenedioxytetrahydroprotoberberine (8), together with 10 known alkaloids. Their structures were determined on the basis of spectroscopic analyses, including 1D-NMR, 2D-NMR, and HR-ESI-MS. The isolated components were evaluated in vitro for cytotoxic activities against eight tumor cell lines, antimicrobial activities against two Gram-positive bacteria and five Gram-negative bacteria, and antifungal activities against five pathogens. Benzo[c]phenanthridine and secobenzo[c]phenantridine alkaloids exhibited significant cytotoxic, antimicrobial and antifungal properties.