为比较不同苦瓜品种果肉多糖的含量和组成差异，以及抗氧化能力和α-葡萄糖苷酶抑制活性，研究选用13个苦瓜品种为材料，分析其多糖、糖醛酸、蛋白质含量及分子量分布，并采用总抗氧化能力指数评价其抗氧化活性，4-硝基酚-2-D吡喃葡萄糖苷（PNPG）法测定其α-葡萄糖苷酶抑制率，同时分析组成和活性的关系。研究结果表明13个品种苦瓜果肉中多糖、糖醛酸、蛋白质含量分别介于5.91~10.62%（干重），25.21~42.37%和3.17~4.60%；苦瓜果肉多糖均包含了2个主要组分，重均分子量（Mw）分布分别为1558.88~3048.56 kDa和33.19~58.74 kDa；ORAC指数变幅为19.39~57.73 μmol Trolox/g；α-葡萄糖苷酶最大抑制活性变幅为4.80~92.67%；ORAC指数与多糖、己糖醛酸和蛋白含量均呈显著正相关（P<0.05）。不同苦瓜品种间多糖的含量组成、抗氧化能力和α-葡萄糖苷酶抑制活性存在显著基因型差异，多糖是抗氧化活性的主要贡献物质，并且己糖醛酸与蛋白质可以增加其抗氧化能力。

In this study, the differences in the content and component of Momordicacharantia L. polysaccharides (MCPs) from 13 different Momordicacharantia L. species as well as their antioxidant activity and inhibitory effect of α-glucosidase were compared. The MCPs molecular weight distribution, polysaccharides, uronic acid, and protein contents were analyzed. In addition, their antioxidant activity was evaluated by oxygen radical absorbance capacity (ORAC). The 4-nitrophenyl-2-β-d-glucopyranoside method was used to measure the α-glucosidase inhibitory activity and to analyze the relationship between the components and the corresponding activity. The results showed that the polysaccharide, uronic acid, and protein content of 13 Momordicacharantia L. species ranged from 5.91% to 10.62% for dry weight, 25.21% to 42.37%, and 3.17% to 4.60%, respectively. Two major components were present in all MCPs, and their molecular weights ranged from 1558.88 to 3048.56 kDa, and 33.19 to 58.74 kDa, respectively. ORAC values of the 13 Momordicacharantia L. species varied from 19.39 to 57.73 μmol Trolox /g. The maximum inhibition ratio of different species on α-glucosidase ranged from 4.80% to 92.67%. Significant positive correlations were observed between ORAC values to polysaccharide, uronic acid, and protein content (P＜0.05). Significant genetic differences were detected in their content, antioxidant activity, and inhibitory effect of α-glucosidase from different species. Polysaccharides are the main active component contributing to the antioxidant activity of the plant, and uronic acid and protein can strengthen their antioxidant activities.

“十二五”国家科技支撑计划课题(2012BAD33B10)；国家重点基础研究发展计划（2012CB722904）；国家级星火计划项目(2013GA780062)；省基金重点项目（10251064001000006）