From the methanolic extract of the climbing stems and rhizomes of Sinomenium acutum, two new aporphine analogues, acutumalkaloids I and II, were isolated together with fifteen known compounds including lysicamine. The chemical structures of the isolated new compounds were elucidated based on chemical/physicochemical evidence such as NMR and MS spectra. For acutumalkaloids I and II, the absolute configurations were established by comparison of experimental and predicted electronic circular dichroism (ECD) data. We compared anti-proliferative activities of isolated compounds with reported naturally occurring Wnt/β-catenin pathway inhibitor, nuciferine. Among the isolated compounds, we found lysicamine have anti-proliferative activity against both of HT-29 human colon cancer cell line and its cancer stem cells (CSCs). The IC₅₀ values of lysicamine against non-CSCs and its CSCs were lower than that of nuciferine. In addition, the results of western blotting analysis suggested that lysicamine inhibited the expression of Wnt/β-catenin pathway target protein such as survivin. These results suggested that lysicamine show cytotoxic activity via inhibition of Wnt/β-catenin pathway.

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