Study On Purification Of Dihydroquercetin And Identification, Quantification Other Flavonoids From Larch

Dihydroquercetin is also called taxifolin. It belongs to vitamin PP in nature.Dihydroquercetin contains five phenolic hydroxyls in the chemical structure. So it determinesthat dihydroquercetin has a variety of biological activities，such as anti-inflammatory,anti-oxidant, liver protection, anti-cancer, anti-radiation and so on. With the development ofscience and technology, more and more people have realized the importance of natural extracts.Dihydroquercetin as an important kind of natural extracts, it has many biological activities, so itis widely used in many fields. But because of the limit of raw materials, production technologyand production, the price is very expensive. n addition to the highest content of dihydroquercetin,whether there are other material, how much their content is and whether they also play a role ina variety of biological activities in dihydroquercetin samples.This article mainly studies that the part of the root in L. olgensis var. koreana is used triplewater reflux extraction diacolation. Then the extracting solution is extracted by methyl tert-butylether and is dissolved with hot water and repeates freezing crystallization3times. The puritiesof the two extractives are78%and92%respectively. And we determine the residues of thesetwo extractives. Two kinds of extractives have no methyl tert-butyl ether.Using HPLC-MS/MS, the there extractives of dihydroquercetin are qualitatively analyzed.The results shows that the two extractives of dihydroquercetin in L. olgensis var. koreanacontaining flavonoids are consistent. The five kinds of flavonoids are dihydroquercetin,aromadendrin, eriodictyol, quercetin and Kaempferol. The extractive of dihydroquercetin inLarix gmelini contains dihydroquercetin, aromadendrin, eriodictyol, quercetin, pinocembrin,naringenin and Kaempferol.Sample one, sample two and sample there of the extractives of dihydroquercet arequantitatively analyzed. The experimental results show that in sample one of the extractive ofdihydroquercetin, dihydroquercetin is78.16%, aromadendrin is2.92%, eriodictyol is1.08%,quercetin is2.36%and kaempferol is0.30%. In sample two of the extractive ofdihydroquercetin, dihydroquercetin is92.07%, aromadendrin is2.39%, eriodictyol is0.19%,quercetin is0.053%and kaempferol is0.045%. In sample there of the extractive ofdihydroquercetin is92.11%, aromadendrin is1.71%, eriodictyol is0.35%, quercetin is0.008%,kaempferol is0.005%, naringenin is0.12%, pinocembrin is0.0006%. At the same time, sample1one is separated and purified by sephadex column LH-20. Another kind of flavonoids monomer which is, quercetin, is obtained besides dihydroquercetin.The antioxidant activity and tyrosinase inhibitory effect of the two extractives ofdihydroquercetin in L. olgensis var. koreana and the extractives of dihydroquercetin in Larixgmelini are studied. The experimental results show that when the purity of dihydroquercetin isthe same, the antioxidant activity of the extractives of dihydroquercetin in Larix gmelini is betterthan that of L. olgensis var. koreana. When the purity of dihydroquercetin is not the same, thehigher the purity of dihydroquercetin in the extractives of dihydroquercetin in L. olgensis var.koreana is, the better the antioxidant activity is. The result shows that dihydroquercetin plays animportant role in antioxidation among the extractives of dihydroquercetin. But other flavonoidsingredients also plays a role in antioxidation. The antioxidant activity of BHT is weaker thanthat of the extractives of dihydroquercetin. This is due to the molecular structure ofdihydroquercetin. In the tyrosinase inhibiting experiment, when the purity of dihydroquercetin isthe same, the tyrosinase inhibitory effect of the extractives of dihydroquercetin in L. olgensis var.koreana. is better than that of Larix gmelini. It may be due to the different flavonoids of theextractive or the different content of the same flavonoids of the extractive apart fromdihydroquercetin.When the purity of dihydroquercetin is not the same, in the low concentrations,the effect of higher purity of dihydroquercetin is better; in the high concentrations, when thepurity of dihydroquercetin is lower, the effect is better. Due to in different purity ofdihydroquercetin extractive, it also contain there are other flavonoids besides dihydroquercetin,and the different content of these flavonoids in the extractive results in the phenomenon. Theextractive of dihydroquercetin in Larix olgensis shows the competitive inhibition for tyrosinase.KIis0.017.When the concentration is0.01g·L-1, BHT works on the opposite role as promoting.It is not suitable for cosmetic whitening ingredients. When the concentration is0.01g·L-1,arbutin on tyrosinase inhibitory effect reaches100%. But it has cytotoxicity, so the extractivesof dihydroquercetin are more suitable for cosmetic whitening ingredients. This article alsostudied the extractive of dihydroquercetin in L. olgensis var. koreana facilitate adrenalinhydrochloride on decomposing isolated adipose tissue. The results show that in the extractive ofdihydroquercetin in L. olgensis var. koreana, when the purity of dihydroquercetin is low, theeffect of the extractive facilitate adrenalin hydrochloride on decomposing isolated adipose tissueis a weak; when the purity of dihydroquercetin is high, the effect is no. The mechanism of actionwith which the extractive of dihydroquercetin in L. olgensis var. koreana facilitate adrenalinhydrochloride on decomposing isolated adipose tissue needs further study.