人心果叶不同极性组分的抗氧化与抗菌活性

通过体外DPPH自由基、ABTS自由基清除能力和总抗氧化能力评价人心果叶不同极性萃取物（石油醚相、乙酸乙酯相、正丁醇相、水相）的抗氧化活性，并探究各极性组分对金黄色葡萄球菌、枯草芽孢杆菌和大肠杆菌的抑制能力。结果表明：乙酸乙酯组分的体外抗氧化活性最强，清除DPPH自由基能力IC₅₀值为（0.019±0.010） mg/mL，总抗氧化能力以水溶性维生素E当量（TEAC）表示，值为（5.824±0.234） mmol/g。当质量浓度达到0.50 mg/mL时，乙酸乙酯组分对ABTS自由基清除率就已经超过了50%；且乙酸乙酯组分能够明显抑制金黄色葡萄球菌的生长，最小抑菌浓度（MIC）和最小杀菌浓度（MBC）分别为0.313，0.625 mg/mL。人心果叶乙酸乙酯组分具有显著的抗氧化和抗菌活性，可用于天然抗氧化剂和抗菌剂的开发。

Antioxidant and antibacterial activities of different polar parts from Manilkara zapota leaves

In order to investigate the antioxidant and antibacterial activity of different polar parts (petroleum ether part, ethyl acetate part, n-butanol part and water part) from Manilkara zapota leaves. The DPPH radical-scavenging assay, ABTS radical-scavenging assay and FRAP antioxidant capacity assay were carried out. And the antibacterial effects of different polar parts from Manilkara zapota leaves against Bacilus subtillis, Escherichia coli and Staphylococcus aureus were studied. The results showed that the extracts obtained from ethyl acetate extraction had the highest antioxidant activities; the IC₅₀ of the DPPH radical-scavenging and ABTS radical-scavenging were (0.019±0.010) mg/mL, and the Trolox Equivalent Antioxidant Capacity (TEAC) value was (5.824±0.234) mmol/g. The ethyl acetate-extracts, at the concentration of 0.50 mg/mL, had >50% scavenging rate according to the ABTS radical-scavenging assay. The ethyl acetate-extracts also showed outstanding resistant activity against Staphylococcus aureus, the MIC and MBC were 0.313 mg/mL and 0.625 mg/mL, respectively. It was confirmed that the ethyl acetate-extracts from Manilkara zapota leaves showed outstanding antioxidant activity and antibacterial activity, and they could be used in the exploring of natural antioxidants and antibacterial agents.