红藻扇形叉枝藻中的降碳倍半萜及其衍生物

Norisoprenoids from red alga Gymnogongrus flabelliformis

目的：对红藻扇形叉枝藻Gymnogongrus flabelliformis进行化学成分研究。方法：利用正相和反相硅胶柱色谱、Sephadex LH-20凝胶柱色谱和反相HPLC等手段进行分离纯化,借助MS,1D和2D NMR等波谱方法鉴定化合物结构；通过MTT法对分离鉴定的单体化合物在人肺癌细胞株(A549)、人肝癌细胞株(Bel 7402)、人胃癌细胞株(BGC 823)、人结肠癌细胞株(HCT-8)和人卵巢癌细胞株(A2780)上进行肿瘤细胞毒活性筛选。结果：从红藻扇形叉枝藻中分离得到5个降碳倍半萜类化合物,分别鉴定为(3S,6R,7E)-(+)-3-hydroxyl-4,7-megastigmadien-9- one(1),(3S,5R,6S,7E)-(-)-3-hydroxy-5,6-epoxy-7-megastig-mene-9-one(2),(3S,5S,6R,7E)-(+)3-hydroxy-5,6- epoxy-7-megastigmene-9-one(3),dehydrovomifoliol(4)和(3R)-(-)-4-[(2R,4S)-4-acetoxy-2-hydroxy-2,6,6-trimethyl- cyclohexylidene]-3-buten-2-one(5)。结论：以上化合物均为首次从该属海藻中分离得到,其中化合物1为新天然产物。细胞毒活性试验结果显示所有化合物在10μg·mL^(-1)均无明显细胞毒活性。

Objective： To investigate the chemical constituents of the red alga GymnogongrusflabeUiformis Harv. Method： Compounds were isolated by normal phase silica gel and Sephadex LH -20 gel column chromatography and reverse phase HPLC. Their structures were elucidated by spectroscopic methods including MS, ^1 H-NMR,^13C-NMR. Cytotoxicity of the compounds was screened by using standard MTT method. Result： Five compounds were isolated from G. flabeUiformis, their structures were identified as（3S, 6R, 7E） -（ ＋ ） -3-hydroxyl-4, 7-mega-stigmadien-9-one （ 1 ）, （3S, 5R, 6S, 7E） -（ - ） -3-hydroxy-5, 6-epoxy-7-megastigmene-9-one （2）, （3S, 5S, 6R, 7E）-（ ＋ ）3-hydroxy-5, 6-epoxy-7-megastigmene-9-one （3）, dehydrovomifoliol （4）, （3R）-（ - ）-4-[ （2R, 4S）-4- aeetoxy-2-hydroxy-2, 6, 6-trimethyleyelohexylidene]-3-buten-2-one （5）. Conclusion： All of the compounds were obtained from this species for the first time and compound 1 was a new natural product. These compounds were inactive （ IC50 〉 10 μg · mL^-1 ） in the MTT assay against several human cancer cell lines.