Antioxidant and Cytotoxic Potential of an Undescribed Lignan Isolated From the Pooled Stem and Leaf Extract of Conocarpus lancifolius.

A previously unknown lignan, methyl-(7S, 8S)-4-hydroxy-4',7-epoxy-8,3'-neolignan-7'-ate (MEHN), was isolated from an extract prepared from the pooled stems and leaves of Conocarpus lancifolius and structurally elucidated using comprehensive spectroscopic analysis and ECD calculations. The compound revealed prominent antiradical activity in both ABTS (IC50 = 18.90 ± 1.85 µM) and DPPH (IC50 = 36.95 ± 2.47 µM) assays, relative to the reference antioxidant ascorbic acid. In an MTT colorimetric assay, MEHN at various concentrations (1.562-200 µM) exerted pronounced cytotoxic effects against HepG2 (IC50 = 14.30 ± 2.70 µM) and MCF-7 (IC50 = 20.81 ± 1.34 µM) cells, while showing weak cytotoxicity against HCT-116, H1299, H522, and non-malignant cell line MCF-10A (IC50 > 100 µM), indicating selective activity against specific cancer cell lines when compared with the standard chemotherapeutic agent 5-fluorouracil. Its computational ADMET evaluation showed favorable pharmacokinetic behavior, compliance with drug-likeness criteria, and low predicted toxicity. Overall, the newly isolated lignan sheds light on the chemical diversity of C. lancifolius with multifunctional biological activities, suggesting its potential relevance for further chemical and pharmacological research.