香椿(Toona sinensis Roem.) 為楝科(Meliaceae) 多年生落葉性喬本植物，因其嫩葉可食，故民間普遍利用當蔬菜食用，並有除熱、止血、解毒、殺蟲及治腸炎等藥效，最近的研究顯示香椿也具有降血糖與抗癌活性之功效。 本研究探討香椿甲醇、水及乙酸乙酯萃取物之抗氧化性質。 在萃取物之抗氧化力方面，甲醇、水及乙酸乙酯萃取液在 10 mg/ml時，分別為 72.1、62.5 和85.4%。 當濃度在 1 mg/ml 時，其還原力以乙酸乙酯萃取最佳(1.35)，而水及甲醇萃取分別為 0.27及0.84。 在清除羥自由基能力方面，於 20 mg/ml 時，以乙酸乙酯萃取最佳 (86.8%)，其次水萃取為 52.9%，而甲醇萃取液並沒有清除羥自由基之能力。在 10 mg/ml時，亞鐵離子之螯合能力依序為水>乙酸乙酯>甲醇。 Toona sinensis Roem., a member of Meliaceae, is a deciduous tree. Because parts of it can be eaten, so the people use the young shoots cooked as a vegetable. According to some research, the whole plant can be used as clear away heat, detoxify kill insects and enteritis etc. Recently, some reports indicate the crude extracts of T. sinensis possessing blood sugar lowering effect of diabetic mellitus and anticancer effect. The research reported herein was to study the antioxidant properties from its methanol, water and EtOAc extracts. At 10 mg/ml, the antioxidant activities of extracts were 72.1 (methanol), 62.5 (water) and 85.4% (EtOAc). At 1 mg/ml, the reducing powers were EtOAc (1.35), water (0.27) and methanol (0.84). At 20 mg/ml, the scavenging effects on hydroxyl radicals were best with EtOAc (86.8%), moderate with water (52.9%), but no effect for methanol. At 10 mg/ml, the chelating effects were in the order of water>EtOAc>methanol.
