耳叶牛皮消中的苯乙酮类化合物及其抗氧化活性研究

Acetophenones and antioxidant activity in Cynanchum auriculatum Royle ex Wight

目的研究耳叶牛皮消(萝藦科)Cynanchum auriculatum Royle ex Wight(asclepiadaceae)块根的化学成分及其抗氧化活性。方法药材提取物分部萃取后采用硅胶、Sephadex LH-20柱层析等进行分离纯化,通过理化性质和光谱分析鉴定结构。在H_2O_2刺激条件下,研究化合物对PC12细胞中超氧化物歧化酶(SOD)活性、过氧化氢酶(CAT)活性以及谷胱甘肽过氧化物酶(GSH-Px)活性的影响。结果从耳叶牛皮消中分离得到了5个苯乙酮类化合物,分别鉴定为cynandione A(Ⅰ)、cynandione B(Ⅱ)、cynandione C(Ⅲ)、cynanchone A(Ⅳ)、cynantetrone(Ⅴ)。H_2O_2能降低SOD、CAT和GSH-Px三种抗氧化酶活性,而耳叶牛皮消中的苯乙酮类化合物可抑制H_2O_2引起的氧化损伤。结论耳叶牛皮消中的苯乙酮类化合物具有抗氧化活性。

Objective To study the chemical constituents and antioxidant activityof the root tubers of Cynanchum auriculatum Royle ex Wight （ asclepiadaceae）. Methods The root tubers were extracted with 95% EtOH, and the ethanol extract was further sepa- rated and purified by repeated column chromatography of silica gel and Sephadex LH-20. Structures of the compounds were identified on the basis of spectral analysis （including NMR and MS） and chemical evidences. Results Five acetophenones were isolated from Cynanchum auriculatum Royle ex Wight. Their structures were characterized as cynandione cynandioneA（Ⅰ）、cynandioneB（Ⅱ）、cynandioneC（Ⅲ）、cynanchoneA（Ⅳ）、cynantetrone（Ⅴ）. H202 decreases SOD, CAT and GSH-Px activities, while the acetophenones could in- hibit H202-induced oxidative damage. Conclusion The acetophenones isolated from the root tubers of Cynanchum auriculatum Royle ex Wight possessed potent antioxidant activities.