In order to investigate the material basis of the uric acid-lowering activity of Gynura procumbens, G. procumbens extracts obtained by hot reflux extraction with different ethanol concentrations (0%, 30% and 70%) were evaluated for bioactive ingredients, xanthine oxidase (XOD) inhibitory activity and antioxidant activity. The extracts were analyzed and identified by non-targeted metabolomics. Meanwhile, the 30% and 70% ethanol extracts, which exhibited high XOD inhibitory activity, was evaluated for uric acid-lowering activity in a mouse model of hyperuricemia induced by hypoxanthine and potassium oxonate. The results showed that the XOD inhibitory activity of the extracts was significantly positively correlated with the total flavonoid and total organic acid contents (P < 0.05 and P < 0.01, respectively), and the superoxide anion scavenging capacity was significantly positively correlated with the total phenol content (P < 0.01). A total of 705 differential metabolites were detected by non-targeted metabolomics. In vitro experiments revealed that naringenin, 1,5-dicaffeoylquinic acid, α-linolenic acid, ferulic acid and diosmetin were the key contributors to the uric acid-lowering activity of G. procumbens. Both 30% and 70% ethanol extracts alleviated hyperuricemia by lowering serum uric acid and inhibiting XOD (P < 0.01), and alleviated hyperuricemia-induced oxidative liver damage. In this study, through in vivo and in vitro experiments, the uric acid lowering activity of G. procumbens was verified, and the basis of the uric acid lowering substance was discussed, which could provide a theoretical basis for the preparation of uric acid-lowering substances from G. procumbens and the development of functional foods with uric acid-lowering activity.

为探究栀子苷与不同热处理大豆分离蛋白的相互作用的机理,以Zeta电位、粒径及微观样貌观察(SEM)为指标对栀子苷-热处理大豆分离蛋白复合物进行表征,并采用荧光光谱法探究栀子苷与不同热处理大豆分离蛋白之间的淬灭方式、结合位点数、结合作用力类型.结果表明,栀子苷会使热处理大豆分离蛋白的Zeta电位绝对值增大,粒径减小,且栀子苷与80℃热处理大豆分离蛋白的复合物Zeta电位绝对值最大,粒径最小;栀子苷与热处理大豆分离蛋白之间淬灭过程是自发的,机制为静态淬灭,相互作用类型为范德华力和氢键,并形成了结合位点数近似于1的复合物.

Alfalfa(Medicago sativa L.) is very important forage in the development of farming and live stock industry in the world.Alfalfa has strong tolerance to drought,but drought is the mainly adversity factor to restrict alfalfa production.In recent years,greenhouse effect is continuously strengthening,and global temperature becomes warm,so it is very important to study crops and pasture tolerance to drought and heat.Six alfalfa were cultivated in the Jianshui County,Honghe,Yunnan Province and their photosynthetic characteristics and response to dry-hot environment were studied.The results showed that net photosynthetic rate of alfalfa No.24 was significantly higher than those of other alfalfa(P0.05).The transpiration rates of alfalfa No.14 and No.15 were significantly higher than those of other alfalfa(P0.05).The stomatal conductances of alfalfa No.15 and No.16 were significantly higher than those of other alfalfa(P0.05).The Internal CO2 of alfalfa No.14 and No.24 were significantly higher than those of other alfalfa(P0.05).Net photosynthetic rate was positively correlated with photosynthetic active radiation,transpiration rate,intercellular CO2 concentration,but it was negatively correlated with stomatal conductance.