丝瓜伤流液的化学组成及体外抗氧化活性的研究

Chemical Composition of Bleeding Sap of Sponge Gourd and in Vitro Antioxidant Activity

摘要: 本文研究了丝瓜伤流液的化学组成及其体外抗氧化活性。首先，分析其富含主要化学物质的含量，通过GC-MS分析其小分子有机物质的组成及含量，并分析温度及浓度对其清除DPPH与•OH的能力及总还原能力的影响，确定其体外抗氧化活性。结果表明：丝瓜伤流液的pH为6.42，固形物为0.4 g/L，总酸(以柠檬酸计)为7.86 mg/L，无机盐为0.32 g/L，总糖为11.213 mg/L，多糖为4.054 µg/L。还原糖、蛋白质、游离氨基酸均未检测出；含有4种烷类，4种酮类，3种醛类，3种酚类，3种胺类和1种酸类物质；丝瓜伤流液的原液对•OH及DPPH清除率最高，分别为63.4%、46.7%；在4℃的条件下，其对•OH及DPPH清除能力及还原能力最强。综合分析，冷藏的丝瓜伤流液原液具有较强的体外抗氧化能力。

Abstract: The physicochemical properties and in vitro antioxidant properties of bleeding sap of sponge gourd were investigated. First, its pH, solid content, total acid, total sugar, polysaccharides, reducing sugar, protein and free amino acid were analyzed. Its organics was detected with GC-MS. After treatment at 4˚C, 25˚C, 50˚C, 75˚C and 100˚C for 4 h, its activity of hydroxyl radical scavenging and DPPH radical scavenging and reducing power were studied at different concentrations (20%, 40%, 60%, 80% and 100%). The results were as follows. Its pH was 6.42 and solid content was 0.4 g/L. The content of total acid in citric acid was 7.86 mg/L and inorganic salt was 0.32 g/L. Its total sugar content was 11.213 mg/L, while polysaccharide content was 4.054 µg/L. Reducing sugars, proteins and free amino acids were not detected. There were 4 alkanes, 4 ketones, 3 aldehydes, 3 phenols, 3 amines and 1 acid. Finally, its hydroxyl radical scavenging activity was 63.4%. Its scavenging activity was nearly 0 after open at air for 50 h and strongest in 4˚C. Its scavenging ability to DPPH radical was 46.7%. The activity was nearly 0 after open at air for 75 h, highest in 4˚C. The reducing ability was highest at 4˚C, which was three times than that at 100˚C. In conclusion, there were probably 3-methyl-1,2-benzenediol, n-valeraldehyde and 3,4-diene-2-heptanone in bleeding sap of sponge gourd. Therefore, its fresh stock solutions had better to be stored at 4˚C in order to preserve its antioxidant activity.