ABSTRACT
Objective To study the cyclic peptides from sponge Reniochalina sp. under the guidance of mass spectrometry. Methods Mass spectrometry-guided procedural separation methods were used to track and isolate the cyclic peptides from the sponge genus Reniochalina. The structures of compounds were elucidated by the determination of physicochemical parameters and comparison of spectroscopic data. The preliminary cytotoxic activity of compounds was assessed by the Cell Counting Kit-8 (CCK-8) method. Results Three cyclic peptides were isolated from the sponge Reniochalina sp. and identified as stylopeptide 1 (1), hymenamide D (2) and axinastatin 2 (3). Compound 1 exhibited cytotoxicity against six human cancer cell lines with IC50 values ranging from 6.09 to 17.26 μmol/L. Conclusion Compound 1 - 3 were isolated from Reniochalina sp. for the first time, and compound 1 was a cytotoxic cyclic heptapeptide.