Luo Xiao-Dong, Basile Margaret J, Kennelly Edward J
Department of Biological Sciences, Lehman College and The Graduate Center, The City University of New York, 250 Bedford Park Boulevard West, Bronx, New York 10468, USA.
J Agric Food Chem. 2002 Mar 13;50(6):1379-82. doi: 10.1021/jf011178n.
Chrysophyllum cainito L. (Sapotaceae), known commonly as star apple or caimito, is a tropical tree that bears edible fruits. The fruits are grown commercially in certain tropical and subtropical areas, such as southern Florida. In this study, the fresh fruits were extracted with methanol and partitioned with hexane and ethyl acetate sequentially. The ethyl acetate soluble fraction displayed high antioxidant activity in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay (IC50 = 22 microg/mL). Activity-guided fractionation of the ethyl acetate soluble fraction was performed to identify the antioxidant constituents. Nine known polyphenolic antioxidants, (+)-catechin (1), (-)-epicatechin (2), (+)-gallocatechin (3), (-)-epigallocatechin (4), quercetin (5), quercitrin (6), isoquercitrin (7), myricitrin (8), and gallic acid, have been identified from the fruits. Of these nine antioxidants, 2 is present in the highest concentration in star apple fruits (7.3 mg/kg fresh weight), and 5 showed the highest antioxidant activity (IC50 = 40 microM) in the DPPH assay.
金星果（Chrysophyllum cainito L.，山榄科），通常被称为星苹果或金星果，是一种能结出可食用果实的热带树木。这种果实于某些热带和亚热带地区商业化种植，比如佛罗里达州南部。在本研究中，新鲜果实先用甲醇提取，然后依次用己烷和乙酸乙酯进行分配。乙酸乙酯可溶部分在1,1 - 二苯基 - 2 - 苦基肼（DPPH）测定中显示出高抗氧化活性（IC50 = 22微克/毫升）。对乙酸乙酯可溶部分进行活性导向分级分离以鉴定抗氧化成分。已从果实中鉴定出九种已知的多酚类抗氧化剂，（+） - 儿茶素（1）、（ - ） - 表儿茶素（2）、（+） - 没食子儿茶素（3）、（ - ） - 表没食子儿茶素（4）、槲皮素（5）、槲皮苷（6）、异槲皮苷（7）、杨梅苷（8）和没食子酸。在这九种抗氧化剂中，2在星苹果果实中的浓度最高（7.3毫克/千克鲜重），5在DPPH测定中显示出最高的抗氧化活性（IC50 =
40微摩尔）。
