中文摘要：

目的：对海藻Galaxaura filamentosa中的抗肿瘤活性化合物进行分离与结构鉴定。方法：采用硅胶低压柱层析、制备薄层层析和重结晶等方法进行分离提取,根据理化性质和光谱数据鉴定结构。结果：分离得到一个新的具有抗肿瘤活性环肽化合物：环-N-甲基亮氨酸-亮氨酸-N-甲基亮氨酸-亮氨酸-亮氨酸。结论：该化合物为新化合物,对肿瘤细胞GRC-1、HepG2的生长具有抑制作用,其IC值分别为：4.26μg/mL和4.63μg/mL。

英文摘要：

Objective：To isolate and identify the antineoplastic constituents of the marine algae Galaxaura filamentosa. Methods： The constituents were isolated and purified by low-pressure silica gel column chromatography, thin layer chromatography and recrystallization, and their structures were elucidated by spectroscopic analysis. Results： Isolated a new antineoplastic cyclic peptide, cyclo-N-methyl-Leucine-Leucine-N-methyl-Leucine-Leucine-Leucine. Conclusion： This new compound was remarkably active against the human renal cell carcinoma GRC-1 and human hepatocellular carcinoma HepG2 cell lines with corresponding IC50 values of 4.26 μg/mL and 4.63 μg/mL.