New Phenanthrene Derivatives from Cylindrolobus mucronatus Lindl. and their Cytotoxic Activity against Glioblastoma Cells.

A detailed phytochemical investigation was carried out on the whole plant of Cylindrolobus mucronatus, representing the first scientific study of this species. The research identified 11 compounds, including four newly discovered structures, cymucronins A-D (1-4), and seven previously known compounds (5-11). The structures of the new compounds were determined using advanced spectroscopic methods, such as nuclear magnetic resonance (NMR) and mass spectrometry. The cytotoxic activities of isolated compounds (1-3, 5-9) were tested against the U-87 MG glioma cell line. The half-maximal inhibitory concentrations (IC(50)) of compounds 3 and 9 were 19.91 ± 4.28 and 17.08 ± 3.72 μM, respectively, indicating the potential of C. mucronatus as a valuable source of cytotoxic natural products. This study provides significant insights into the phytochemical and pharmacological properties of C. mucronatus, supporting its potential for further exploration in anticancer medicinal research.