三列凹顶藻化学成分研究Ⅱ

Studies on chemical constituents of Laurencia tristicha(Ⅱ)

目的：从三列凹顶藻Laurenciatristicha中寻找具有多样性结构的化学成分，供药理活性筛选。方法：采用凝胶柱色谱、硅胶柱色谱、重结晶和高效液相色谱等方法进行分离；借助核磁共振等波谱方法鉴定化合物的结构；用MTT法对得到的化合物进行细胞毒活性评价。结果：分离得到7个化合物，分别鉴定为鉴定为胆甾醇（1），胆甾-5-烯-3β，7βα二醇（2），β-谷甾醇（3），叶绿醇（4），玉米黄素（5），对羟基苯甲醛（6），3-吲哚甲醛（7）；在人肿瘤细胞株HCT-8，Bel-7402，BGc-823，A549和HELA模型上，化合物2对所有细胞株均显示毒性，化合物4对HCT-8和HELA细胞显示中等强度的细胞毒活性，其它化合物对所有细胞株均无明显毒性，IC50均大于10．0μ·mL^-1。结论：化合物1—7均为首次从三列凹顶藻中得到，化合物2对所有细胞株均显示毒性，化合物4对HCT-8和HELA细胞具有中等强度的选择性细胞毒活性。

Objective： To search for chemical constituents with structural diversity from Laurencia tristicha to supply for biological assay. Method： Compounds were isolated by means of column chromatography over normal phase silica gel and Sephadex LH - 20, recrystallization and HPLC. Structures were identified by spectroscopic methods including 1D NMR, IR and MS. Cytotoxicities of the purified compounds were evaluated by MTF method. Result： Seven compounds were isolated from L. tristicha. Their structures were elucidated as cholesterol （1）, cholesta- 5-en-3β, 7α-diol （2）, β-stigmasterol （3）, phytol （4）, zeaxanthin （5）, 4 -hydroxy- benzaldehyde （6）, indolyl-3-carbaldehyde （7）. In the cytotoxic assay compound 2 was active against human cancer cell lines HCT-8, Bel-7402, BGc-823, A549 and HELA with IC50 values of 1.90, 2.02, 1.99, 6.52 and 1.20 μg · mL^-1 , respectively. Compound 4 showed cytotoxicity against HCT-8 and HELA with ICso value of 3.51 and 2. 04 μg · mL^-1 , and other compounds were inactive （IC50 〉 10 μg · mL^-1 ）. Conclusion： Compounds 1-7 were isolated from L. tristicha for the first time. In additon, compounds 2 and 4 were cytotoxic against several human cancer cell lines.