Bioactive isoquinoline alkaloids from Cissampelos pareira^†

The phytochemical and biological investigation of Cissampelos pareira leads to the isolation of one new isoquinoline alkaloid (7) along with six known isoquinoline alkaloids, namely, magnoflorine (1), magnocurarine (2), cissamine (3), curine (4), hayatinine (5) and cycleanine (6). Magnoflorine (1) and magnocurarine (2) were isolated for the first time from C. pareira. A new, rapid, simple and sensitive UPLC method was developed for simultaneous quantification of five pure compounds (1–5). Seasonal variation study revealed higher content of these compounds during the rainy season. The chloroform (CPCF) and n-butanol (CPBF) fractions showed cytotoxic efficacy against KB cells. Among pure compounds, hayatinine (5) was found to be most active against KB and A549, while, cycleanine (6) against KB cells.