Four new alkaloids, characterized as 6-(2-hydroxyethyl)-5,6-dihydrosanguinarine (1), 6-acetonyl-5,6-dihydrosanguinarine (2), N-methyl-2,3,7,8-tetramethoxy-5,6-dihydrobenzophenanthridine-6-ethanoic acid (3), N-methyl-2,3,7,8-tetramethoxy-6-oxo-5,6-dihydrobenzophenanthridine (4), together with