[摘要]:Two new cembranoids, yalongenes A (1) and B (2), were isolated from the South China Sea soft coral Sarcophyton trocheliophorum Marenzeller. Their structures were elucidated by detailed spectroscopic analysis (IR, MS, and NMR) and by comparison with a related model compound. Yalongenes 1 and 2 were evaluated for their cytoprotective effects on SH-SY5Y cell injury induced by H2O2 in vitro, and the result showed that only compound 1 had a significant cytoprotective activity at the concentration of 1 mu M.