基根硬毛藻中的无环二萜和脂肪族化合物及其活性

Acyclic diterpenoids and aliphatic compounds from green alga Chaetomorpha basiretorsa and their activities

目的研究绿藻基根硬毛藻Chaetomorpha basiretorsa的化学成分,从中寻找结构特殊的化合物供活性筛选。方法利用正相和反相柱色谱、SephadexLH-20柱色谱、反相HPLC以及重结晶等手段进行分离纯化,借助MS、IR、1D和2D NMR等方法鉴定结构;通过MTT法对分离鉴定的单体化合物在人肿瘤KB、Bel-7402、PC-3M、KeTr3和MCF-7细胞株上进行细胞毒活性测试,并测试对犬血管平滑肌细胞的增殖抑制活性。结果从基根硬毛藻中分离得到4个二萜类化合物和2个脂肪族类化合物,分别鉴定为7,11,15-trimethyl-3-methylene-hexadecan-1,2-diol(Ⅰ)、3,7,11,15-tetramethyl-hexadecan-1,3-diol(Ⅱ)、phytol(Ⅲ)、phytenal(Ⅳ)、甘油-1-软脂酸酯(Ⅴ)和十六烷-3-烯酸(Ⅵ)。结论所有化合物均为首次从本属海藻中分离得到,其中化合物Ⅱ为新天然产物。细胞毒活性测试中,化合物Ⅰ对KB细胞、KeTr3细胞和MCF-7细胞具有一定毒性,IC50分别为3.42、2.38、1.78μg/mL。化合物Ⅰ、Ⅲ、Ⅵ对犬血管平滑肌细胞增殖显示一定抑制活性。

Objective To study the chemical constituents of the green alga Chaetomorpha basiretorsa aiming at searching for bioactive natural products. Methods Compounds were isolated by various chromatographic techniques including column chromatography over normal phase silica gel, Sephadex LH-20 gel, reverse phase HPLC, as well as recrystallization. Their structures were determined by spectroscopic methods including IR, MS, 1D, and 2D NMR techniques. MTT Method was used for testing the cytotoxicity against human cancer cell lines KB, Bel-7402, PC-3M, KeTr3, and MCF-7, and the inhibitory activity against dog vascular smooth muscle cell proliferation. Results Four acyclic diterpenes and two aliphatic carboxylic acids were isolated from the ethanolic extract of the green alga C. basiretorsa. Their structures were identified as 7, 11, 15-trimethyl-a-methylene-hexadecan-1, 2-diol （ Ⅰ ）, 3, 7, 11,15-tetramethyl- hexadecan-1, 3-diol （ Ⅱ ）, phytol （ Ⅲ ）, phytenal （ Ⅳ ）, glycerol-l-hexadecanoate （ Ⅴ ）, and hexdec-3- enoic acid （Ⅵ）. Conclusion All these compounds are obtained from the plants of Chaetomorpha Kuetz. for the first time. Compound Ⅱ is firstly reported as a natural product. Compound Ⅰ shows the moderate cytotoxic activity against human cancer cell lines KB, KeTr3, and MCF-7 with IC50 values of 3.42, 2.38, and 1.78μg/mL, respectively, and other compounds are in active （IC50〉10μg/mL）. Compounds Ⅰ , Ⅲ , and Ⅵ show moderate inhibition against proliferation of vascular smooth muscle cells.