| Tengcha is one of the special plants of China for beverage or medicine use, which enriches of flavones. Much attention about the Tengcha focused on the identification of active components and its' antioxidant, antibacterial, hypoglycemic effects, et al. The studies of this article were as follow: Conditions and parameters for extracting of flavones, dihydromyricetin(DHM) of Ampelopsis grossedentata and its activities; The contents of flavones, DHM, activities from different materials; The conditions of purifying flavones using macroporous adsorbing resins; The safety and Lipid-lowering effects of drinking Tengcha; The Lipid-lowering effects and mechanism of flavones and dihydromyricetin from tengcha. We expect these studies were beneficial to tengcha's use.1 Extracting conditions of flavones of TengchaThe effects of extracting temperature, time, the ratio of Tengcha and water, ethanol consistency on the extracting rates of flavones, DHM, the purity of material flavones and its activities were studied. The results showed that the factors of temperature, time, the ratio of Tengcha and water had significant effects on extractions of flavones and DHM. The model of regression of flavones extracting rate was statistically significant at 1% level and was appropriate to express response variables. Considering high extracting rates, purity and activity of the flavones, the better variable levels were -0.8～1 ethanol consistency(67%-85 %), 0～1 temperature(65℃～77.5℃), -1～0.3 heating time (60min-100min), 0-1 ratio of Tengcha and water(1:30-40). The optimum conditions of extracting DHM were -0.8～-0.03 temperature (55℃-65℃), -0.1～0.1 heating time(86min-93min), 0-0.5 ratios of Tengcha and water(1:30-35), 0.5-0.1 ethanol consistency(74%-80%), according to the extracting rate of DHM and its purity.2 Contents of flavones and its' activities of different Tengcha materialsThe contents of flavones and DHM of different ripening Tengcha materials and the abilities of scavenging the O2·- radicals of the flavones have been studied. The results showed that the contents of flavones and DHM, the abilities of flavones scavenging O2·- radicals decreased with the ripening of materials. The contents of flavones in stems were less than that of flavones in leaves, but the scavenging O2·- radicals effect of flavones from stems was better than that of flavones from leaves. It was revealed that bioactive flavones were mainly existed in leaves especially growing vigorously and varied in flavones compositions between leaves and stems.Conditions of cultivation effected the contents of flavones, DHM and the abilities of scavenging the O2·- of flavones. The tendency of the contents of flavones and DHM, the abilities of scavenging the O2·- of flavones were uncultivated materials＞half cultivated materials＞cultivated materials. It was revealed that conditions of living environment had great effects on physiology of Tengcha.The contents of flavones and DHM, the abilities of scavenging the O2·- of flavones from Hunan, Hubei, Guangdong, Guangxi, Jiangxi, Fujian were analyzed. The results showed that the contents of flavones and DHM from Guangdong Liannan, Fujian Wuping, Jiangxi Dingnan were the highest, but that from Hunan Sangzhi, Chaling, Enshi Laifeng were the lest. The abilities of scavenging the O2·- of flavones had litter correlation with the contents of flavones(r=0.2769), but DMY(r=0.8330). This revealed that the activity of flavones was related on its' composition and DHM was the main active component.The contents of flavones, DHM from different shape leaves were different, which the middle shape leaves contained more flavones and DHM than that of large shape leaves significantly. The effects of scavenging the O2·- radicals of flavones from small shape leaves were the highest, that of flavones from large shape leaves were the lowest. Breed with middle or small shape leaves might be a good selected.3 Purification and structure identification of flavones from TengchaExperiments of 11 kinds of macroporous adsorbing resins adsorbing and desorbing flavones showed that number 1 was one of the most appropriate resins in all for preliminary purification of flavones, and the adsorbing capacities were 41.41mg/g, desorbing rate were 89.5%. In column of number 1, the optimum conditions were that the concentration of crude flavones was 6-7mg/ml, the volume of sample was 1/3 or 1/4 that of column, flowing velocity was 1.8ml/min, eluting solution was 95% ethanol, which led to 65% purity of the flavones and 90% desorbing rate of flavones. The flavones which was purified by recrystallization was dihydromyricetin, according to UV, IR, and LC-MS analysis.4 Toxicology assessments on safety of TengchaThe safety of water extracting of Tengcha on the animal was investigated according to the Standard of Health Food Test and Assess. Acute toxicity test on mice showed that LD50 was greater than 30g/Kg.bw. Three genetic tests showed negative results. 90 days feeding test investigated that the outer appearance, behavior, weights, organ coefficients, the indexes of hematology and biochemistry in rats have no significant difference comparing with the control group. Significant pathological changes of inherent organs were not discovered. All the results showed that drinking Tengcha was safety on Rats. 5 The Serum Lipid-Lowering Action of Water Extracting from Tengcha on Rats and HumanThe serum Lipid-lowering effects of water extracting of Tengcha was studied. The results showed that the TC level of high group (4.5g/Kg.bw) and the TG levels of both middle (3.0g/Kg.bw) and high group dropped greater than the positive control group significantly. However, HDL-C levels in the three Tengcha treated groups were higher significantly (p＜0.05). Clinical trial showed the effective rate of lowering TC, TC, and serum lipid of Tengcha on human were 42.0%, 72.0%, 28.0%. The TC, TG level of Tengcha treated groups dropped greater than before or the control group significantly (p＜0.01). The indexes hematology and biochemistry of the Tengcha treated groups did not change significantly. Tengcha was safe and effective on lowering rats and human serum lipid.6 The Hypolipidemic Effect of Flavones and Dihydromyricetin from TengehaThe effects of Tengcha flavones and dihydromyricetin (DHM) on hypolipidemic mice were investigated. The results showed, compared with the hyperlipidemia control group, 0.5g/kg.bw DHM reduced the weights of mice significantly; Serum TG level distinctly dropped with each dose flavones and 0.3g/kg bw DHM which also decreased serum TC,TG,LDL-C levels. 0.5g/kg.bw DHM increased serum HDL-C. Each dose of flavones and DHM enhanced the activities of SOD and reduced the content of MDA and liver coefficient. The liver tissue pathology observation showed that Tengcha flavones and DHM could lighten liver cell denatured. As results, Tengcha flavones and DHM could prevent hypolipidemia in mice and protect myocardial cells from oxidation and the liver from harm of high lipid.7 Spectroscopic Investigation of the Interaction between Dihydromyricetin and Bovine Serum AlbuminThe mechanism of interaction between dihydromyricetin (DHM) and bovine serum albumin (BSA) has been investigated by UV absorption and fluorescence spectrum. The results showed that DHM existed at anion and caused the UV absorption red shift at alkalescent condition; DHM with different concentration caused the UV absorption spectrum of BSA red shift at physiology pH7.4. DHM showed the florescence quenching on BSA. The quenching rate constant was 3.97×1012, which suggested as static quenching process. The number of binding sites was 1.97, and the binding constant was 5.04×109. Ca2+,Zn2+,Mn2+,Cu2+,Fe3+ could increase quenching rate constant and decrease the binding constant and binding sites between DHM and BSA, while Fe3+ could increase the binding constant and binding sites. |
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