Medicinal Ingredients Of Gynostemma Pentaphyllum Under Various Culturing Conditions And Prediction Of Medicinal Ingredients In G. Pentaphyll Um Extract

Gynostemma pentaphyllum is a perennial liana. Because of the strong antioxidative activity and delaying senility, it is praised as the "second ginseng ". At present, G. pentaphyllum has recently been massively cultivated in China and has also been exported to Europe as an herbal tea with market development and application value. There are a large number of researches on gypenosides and the synthesis pathway, but few researches were studied on other plant active substances, photosynthetic characteristics and the relationship between photosynthesis and temperature or carbon dioxide concentrations. In this study, four culturing conditions are set:24/19℃,360±50ppm CO2(ck);28/23℃,360±50ppm CO2(T);24/19℃,720±50ppm CO2(C);28/23℃,720±50ppm CO2(CT). We discuss the changes of photosynthetic characteristics and bioactive compounds’contents under various culturing conditions. And we try to evaluate the bioactive compounds’contents of G. pentaphyllum water extracts through mathematical modeling. Main research results are as follows:1. High temperature and CO2concentration improve the biomass of G. pentaphyllum, obviously in inflorescences. The pigment contents in tender leaves were increased under the high temperature and CO2concentration. Besides, electron transport rate (ETR), photochemical quenching (qP), actual photochemical quantum Yield (Yield), instantaneous photosynthetic rate (Photo), transpiration rate (Trmmol), stomatal conductance (Cond) and intercellular CO2concentration (Ci) are found significant gains under the high temperature and CO2concentration.2. There are significant differences in the bioactive compounds’contents in different G. pentaphyllum organs. They are maximum in inflorescences, followed by tender leaves and mature leaves, minimum in stems. The influence to bioactive compounds’contents is not immutable in organs under different temperature and CO2concentration. On balance, high temperature and CO2concentration decrease the total flanonoids and phenols contents in organs, but increase the solution sugars contents. Therefore, the radical scavenging activity come down as the same of total flanonoids and phenols contents.3. There are significant differences in the contents of Gypenoside XLIX, myricetin, quercetin, kaempferol in different G. pentaphyllum organs. They are maximum in inflorescences, followed by leaves, minimum in stems. There are significant differences in the ratio of myricetin, quercetin, kaempferol in the different G. pentaphyllum organs. Myricetin occupies a large proportion, kaempferol secondly, quercetin least. Quercetin is undetected in leaves, especially. High temperature and high CO2concentrations promoted the contents of Gypenoside XLIX in G. pentaphyllum leaves; High temperature is not benefit for the accumulation of myricetin, quercetin, kaempferol in inflorescences and leaves, but in stems. High CO2concentration is not benefit for the accumulation of myricetin, quercetin, kaempferol in leaves, but in inflorescences and stems.4. By comparing of the prediction accuracy under different kernel functions, we found that the RBF SVM offers the best correlation coefficients for testing sets (0.9396for TP content,0.9269for TF content, and0.9219for SA). By comparing of the correlation coefficients under different parameter optimization methods, we found that the PSO method has better generalization capability, faster convergence rate and stronger generalization capability than the other two.To sum up, G. pentaphyllum show the higher efficiency of photosynthesis, higher biomass and total sugar content under the higher temperature and CO2concentration culturing conditions. But it’s adverse to the accumulation of myricetin, quercetin, kaempferol, total flavonoids and total phenols. Though higher temperature and CO2concentrations culturing conditions increase in the production of G. pentaphyllum, but sacrifice the quality. We conclude that SVM can be widely employed for the quality analysis of natural plant extracts for the prediction of not only the total phenols, flavonoids, and DPPH radical scavenging activity but also for the control of food nutrient quality during processing.