Three new alkaloids from Corydalis saxicola and their antiproliferative activity

Abstract

Three undescribed protoberberine alkaloids, named corydalisine L-N, along with four known compounds, were isolated from Corydalis saxicola. Their structures were accurately characterized using nuclear magnetic resonance (NMR) and mass spectrometry (MS). The absolute configurations were determined through the calculation of electronic circular dichroism (ECD). Compounds 1–3 were relatively rare 8,13-dicarbonyl protoberbine alkaloids, which are uncommon in plants of the genus Corydalis. All compounds were evaluated for their cytotoxicity against four human cancer cell lines.