目的 研究唐古特虎耳草Saxifraga tangutica的化学成分，并从中筛选抗氧化活性成分。方法 利用硅胶柱色谱、Sephadex LH-20凝胶柱色谱、ODS反相柱色谱和半制备HPLC等色谱技术对唐古特虎耳草乙醇提取物进行分离纯化，根据所分化合物的理化性质及波谱数据进行结构鉴定。采用DPPH法评价所分化合物的体外抗氧化活性。结果 从唐古特虎耳草乙醇提取物中分离得到14个化合物，分别鉴定为6-(3,4-二羟基苯基)己-2-酮（1）、杜鹃醇（2）、覆盆子酮（3）、pinoresinol-4-O-glucoside（4）、rel-(2α,3β)-7-O-methylcedrusin（5）、二氢脱氢松柏醇-3a-O-α-L-吡喃鼠李糖苷（6）、5,7-二羟基色原酮（7）、金丝桃苷（8）、槲皮素-7-O-β-D-吡喃葡萄糖苷（9）、槲皮素（10）、异鼠李素-3-O-β-D-半乳糖苷（11）、槲皮素-3-O-α-L-阿拉伯吡喃糖苷（12）、byzantionoside B（13）和capitsesqside C（14）。抗氧化活性研究结果表明，化合物1、8～10和12对DPPH自由基的半数抑制浓度（median inhibition concentration，IC₅₀）值分别为（627.06±12.90）、（75.16±4.15）、（180.63±2.27）、（154.83±4.21）、（110.33±0.73）μmol/L。结论 化合物1为新化合物，命名为虎耳草酮（saxifragone），其中化合物4～6、13和14均为首次从虎耳草属植物中分离得到，化合物7和12为首次从唐古特虎耳草中分离得到。化合物8的抗氧化能力与阳性药L-抗坏血酸相当，化合物9、10和12的抗氧化能力弱于阳性药，新化合物1具有较弱的抗氧化能力。

Objective To investigate the chemical constituents of Saxifraga tangutica and screen isolated compounds for antioxidant activity. Methods The ethanol extract of S. tangutica was isolated and purified using various chromatographic techniques, including silica gel column chromatography, Sephadex LH-20 gel column chromatography, ODS column chromatography, and semi-preparative HPLC. The isolated compounds’ structures were elucidated through the analysis of their physicochemical properties combined with their spectroscopic data. The in vitro antioxidant activity of the compounds was evaluated using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay. Results A total of 14 compounds were isolated and identified as 6-(3,4-dihydroxyphenyl)hexan-2-one (1), rhododendrol (2), frambinone (3), pinoresinol-4-O-glucoside (4), rel-(2α,3β)-7-O-methylcedrusin (5), dihydrodehydro- diconiferyl-3a-O-α-L-rhamnopyranoside (6), 5,7-dihydroxychromone (7), hyperoside (8), quercetin-7-O-β-D-glucoside (9), quercetin (10), isorhamnetin-3-O-β-D-galactoside (11), quercetin-3-O-α-L-arabinopyranoside (12), byzantionoside B (13), capitsesqside C (14). The antioxidant activity assays indicated that compounds 1, 8—10, and 12 scavenged DPPH radicals with IC₅₀ values of (627.06 ± 12.90), (75.16 ± 4.15), (180.63 ± 2.27), (154.83 ± 4.21), and (110.33 ± 0.73) μmol/L, respectively. Conclusion Compound 1 is a new compound, designated saxifragone (1). Compounds 4—6, 13, and 14 were isolated from genus Saxifraga for the first time, Compounds 7 and 12 were isolated from S. tangutica for the first time. In the antioxidant evaluation, compound 8 exhibited activity comparable to that of vitamin C, while compounds 9, 10, and 12 were weaker than that of the control. The new compound 1 demonstrated weak antioxidant activity.

R284.1

国家自然科学基金地区基金资助项目(82260825);江西中医药大学校级科技创新团队发展计划(CXTD22002)