中文摘要：

目的研究采自中国西沙群岛海域的一种豆荚软珊瑚Lobophytum sp.的化学成分。方法采用硅胶柱色谱和高效液相色谱等方法进行分离纯化,根据理化性质和波谱分析方法鉴定化合物的结构。结果从豆荚软珊瑚Lobophytum sp.的95%乙醇提取物中分离得到6个二萜类化合物,分别鉴定为豆荚内酯B（1）、（1S＊,3S＊,4S＊,7E,11E）-3,4-epoxy-13-oxo-7,11,15-cembratriene（2）、（2E,4E,7R,8S,12Z）-1-isopropylcyclotetradeca-4,8-dimethyl-7-hydroxy-1,3,11-triene-8,12-carbolactone（3）、（2E,4E,8S,12Z）-1-isopropyl-4,8-dimethyl-7-oxocyclotetradeca-1,3,11-triene-8,12-carbolactone（4）、sarcrassin D（5）、laevigatol B（6）。结论化合物1为新化合物,化合物2-4为首次从该属软珊瑚中分离得到。

英文摘要：

Objective To study the chemical constituents of a kind of soft coral Lobophytum sp. collected from Xisha islands of China. Methods Isolation and purification of the chemical constituents were performed by silica gel and ODS gel column chromatographies as well as HPLC. Their structures were determined on the basis of physicochemical properties and spectroscopic methods. Results Six diterpenoids were obtained in 95% ethanol extract from Lobophytum sp., including chilobolide B（1）,（1S＊,3S＊,4S＊,7E,11E）-3,4-epoxy-13-oxo-7,11,15-cembratriene（2）,（2E,4E,7R,8S,12Z）-1-isopropylcyclotetradeca-4,8-dimethyl-7-hydroxy-1,3,11-triene-8,12-carbolactone（3）,（2E,4E,8S,12Z）-1-isopropyl-4,8-dimethyl-7-oxocyclotetradeca-l,3,11-triene-8,12-carbolactone（4）, sarcrassin D（5）, and laevigatol B（6）. Conclusion Compound 1 is a new compound named chilobolide B. Compounds 2—4 are obtained from Lobophytum sp. for the first time.