RESUMEN
Objective: To study the chemical composition of the marine characteristic resource, Onchidium verruculatum from Hainan Island. Methods: Compound was separated and purified by silica gel and semi-preparative HPLC, detected by TLC, and identified by NMR and MS data. Compound 1 was evaluated for cytotoxic activity against four kinds of human tumor cell lines HepG-2, BEL-7042, A549, and MCF-7. Results: A new amide compound, N-(2-hydroxy-4-methoxy-5-methylphenyl)formamide (1), was isolated from mucus and muscle tissue of O. verruculatum. The results showed that compound 1 has moderate toxic activity against A549 and BEL-7402 cell lines, with IC50 value of 11.5 μg/mL and 19.4 μg/mL. Conclusion: Compound 1 is a new amide compound named onchumamide with moderate toxic activity on human tumor cells.