Jiang H, Zhan W Q, Liu X, Jiang S X
Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, China.
Nat Prod Res. 2008 Dec;22(18):1650-6. doi: 10.1080/14786410701875686.
The antioxidant properties of the various extracts and flavonoids prepared from Oxytropis falcate Bunge were investigated by 1,1-diphenyl-2-picryldydrazyl (DPPH) radical-scavenging assay. In the chloroform, ethyl acetate and n-butanol extracts, the ethyl acetate extract exhibited the highest antioxidant activity (IC(50) = 2.05 mg mL(-1)). Furthermore, rhamnocitrin, kaempferol, rhamnetin, 2',4'-dihydroxychalcone and 2',4', beta-trihydroxy-dihydrochalcone were purified from chloroform and ethyl acetate extracts. The radical-scavenging activities of the five compounds were also measured and the results showed that kaempferol (IC(50) = 0.11 mg mL(-1)), rhamnetin (IC(50) = 0.14 mg mL(-1)) and rhamnocitrin (IC(50) = 0.15 mg mL(-1)) exhibited considerable antioxidant activities, but the antioxidant activities of the two dihydrochalcones were very weak. Although these flavonoids are known, this is the first report of antioxidant activity in this plant.
通过1,1-二苯基-2-苦基肼基（DPPH）自由基清除试验，对镰形棘豆制备的各种提取物和黄酮类化合物的抗氧化性能进行了研究。在氯仿、乙酸乙酯和正丁醇提取物中，乙酸乙酯提取物表现出最高的抗氧化活性（IC(50) = 2.05 mg mL(-1)）。此外，从氯仿和乙酸乙酯提取物中纯化出了鼠李柠檬素、山柰酚、鼠李素、2',4'-二羟基查耳酮和2',4',β-三羟基二氢查耳酮。还测定了这五种化合物的自由基清除活性，结果表明山柰酚（IC(50) = 0.11 mg mL(-1)）、鼠李素（IC(50) = 0.14 mg mL(-1)）和鼠李柠檬素（IC(50) = 0.15 mg mL(-1)）表现出相当的抗氧化活性，但两种二氢查耳酮的抗氧化活性非常弱。虽然这些黄酮类化合物是已知的，但这是关于该植物抗氧化活性的首次报道。
