Comprehensive Metabolite Profile and Cytotoxic Constituents of Cryptolepis decidua

High Resolution Image Download MS PowerPoint Slide Root extracts of Cryptolepis decidua are used in the traditional medicine of South-West Africa to treat various conditions. Here, we report the potent cytotoxic activity of a methanol root extract against a human adenocarcinomic cell line, which prompted us to establish a comprehensive metabolite profile. Overall, six previously undescribed compounds were isolated from this extract by a combination of open-column chromatography (CC), centrifugal partition chromatography (CPC), and preparative HPLC. They include two sarmentogenin-type cardenolides ( 2 and 3 ), an androstane lactone ( 5 ), two dinormonoterpenoid diglucosides, dinosides A and B ( 9 and 10 ), and a quinic acid derivative ( 12 ). In addition, six previously reported constituents were identified ( 1, 4, 6 – 8, 11 ). The structures of the isolates were elucidated using HPLC-MS 2/3, HRESIMS, and NMR spectroscopy. Feature-based molecular networking was used to map a comprehensive metabolite profile. The cytotoxic activity of the methanol extract was evaluated by WST-1 cell-viability assays, apoptosis/necrosis tests, and cell-cycle analyses. Cardenolides 1 – 3 were identified as the primary cytotoxic agents, exhibiting IC 50 values of 0.25 μM ( 1 ), 2.20 μM ( 2 ), and 0.28 μM ( 3 ) in A549 human lung epithelial cancer cells, and 0.41 μM ( 1 ), 2.31 μM ( 2 ), and 0.39 μM ( 3 ) against peripheral blood mononuclear cells (PBMCs).