叠鞘石斛的化学成分研究

目的研究叠鞘石斛Dendrobium aurantiacum var.denneanum药材的化学成分。方法应用硅胶、大孔吸附树脂AB-8、Sephadex LH-20凝胶柱色谱以及高效液相制备色谱等方法进行分离纯化,根据质谱和波谱数据鉴定化合物的结构,同时采用MTT法进行抗肿瘤活性筛选。结果从叠鞘石斛茎中分离鉴定了9个化合物,分别为(-)-(7R,7′R,8R,8′S)-4,4′-二羟基-3,3′,5,5′-四甲氧基-7,9′-环氧木脂烷-7′,9-内酯()、(-)-丁香脂素()、(-)-开环异落叶松脂素-4-O-β-D-葡萄糖苷()、拖鞋状石斛素()、石斛酚()、杓唇石斛素()、(+)-柚皮素()、反式肉桂酸甲酯-2-O-β-D-葡萄糖苷()、香草酸()。其中,化合物对A549、Hep G2、A2780肿瘤细胞增殖具有不同程度的抑制作用,IC50分别为5.49、51.2、119.3μmol/L。结论化合物为新化合物,命名为石斛脂素;且对3种人肿瘤细胞具有一定的细胞毒作用。

Antioxidant phenanthrenes and lignans from Dendrobium nobile

To study the antioxidant constituents from the stems of Dendrobium nobile, and to discuss theft structure-activity relationship. Compounds were isolated from a 60% ethanolic extract by various chromatographic techniques and were identified by spectral analysis. The antioxidant activities of compounds were evaluated by DPPH free radical scavenging assay. Five phenanthrenes and four lignans were obtained from the active fractions ofD. nobile. Their structures were identified as fimbriatone （1）, confusarin （2）, flavanthrinin （3）, 2,5-dihydroxy-4,9-dimethoxyphenanthrene （4）, 3,7-dihydroxy-2,4-dimethoxyphenanthrene （5）, syringaresinol （6）, pinoresinol （7）, medioresinol （8） and lirioresinol-A （9）, respectively. Compounds 2 and 6 exhibited more potent DPPH scavenging activities than vitamin C. All the above compounds were reported from this plant for the first time, and compounds 3, 4 and 9 were reported for the first time from the genus of Dendrobiurn. For all phenanthrenes and lignans, an electron-donating methoxyl group in the ortho position to the phenolic hydroxyl group exhibits enhanced antioxidant activities.