Studies On The Chemical Components Of Ilex Latifolia Thunb.and Its Bioactivities

Ilex latifolia Thunb.(Aquifoliaceae),one of the species in Ilex genus,is an evergreen plant,which is one of the maintream products of kudingcha.Ilex latifolia Thunb mainly contains three terpenoid saponins?polyphenols? polysaccharides and volatile oils,it has the pharmacological effects of lowering blood pressure?lowering blood lipid?antibacterial and anti-inflammatory,it is used to treat hypertension? hyperlipidemia and hyperglycemia.In this paper,we had researched the chemical composition?antioxidant activity?spectral efficiency relationship and the structure activity relationship of saponins and xanthine oxidase,It provided the basis and basis for the effective substances and quality control of Ilex latifolia.In this paper,we had systematically investigated the chemical constituents from the ethyl acetate extraction of 70% ethanol extract of Ilex latifolia Thunb,and had been isolated 17 compounds,the structures of 13 compounds were elucidated as Lupeol?Ursolic acid??-Sitosterol?EGCG?Kudinsoide A?Latifolosides A?Latifolosides D?Kudinsoide D?Kudinsoide F ? 3,9-Bis(2,4-di-tert-butylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]-undecane ?ferulic acid?Latifolosides B?Latifolosides G.compound 10 was isolated from this plant for the first time.In this paper,the folin-Ciocalteu colorimetric method?vanillin glacial acetic acid?sodium nitrite method and phenol sulfuric acid method were developed for the determination of the content of total polyphenols?total saponins?total flavonoids and total polysaccharide.The DPPH free radical scavenging ability,ABTS free radical scavenging ability and total reducing power were used to evaluate the in vitro antioxidant activity of the polar parts of Ilex latifolia Thunb.The content of total polyphenols in ethyl acetate extract of Ilex latifolia was the highest.the content of total flavonoids and total saponins in n-butanol extract was the highest,the content of total polysaccharide was the highest in the extraction area of water.Ethyl acetate extract from Ilex latifolia had the best antioxidant activity in vitro.In this paper,HPLC method was used to establish the fingerprints of 10 batches of Ilex latifolia from different habitats,and principal component analysis was performed.HPLC method was used to study the inhibitory activity of different batches of Ilex latifolia on xanthine oxidase,and correlation analysis was performed.A hyperuricemia model of mice was induced by potassium oxazine.The levels of UC and XOD in serum and the level of XOD in liver tissue were detected.The results show that there are 15 characteristic peaks in HPLC fingerprint of 10 batches of Ilex latifolia from different habitats,and peak 11 and 14(Kudinoside F)were correlated with xanthine oxidase inhibition,and peak 5,6(Kaempferol-3-O-?-D-rhamnoside),7(Isorhamnetin-3-O-?-D-rhamnoside),10(Latifoloside C)and 13(Latifoloside D)were the strongest.According to principal component analysis,peak 9(Latifoloside H)plays an important role in the quality control of Ilex latifolia.The high,medium and low dose groups of the extract of Ilex latifolia.can significantly reduce the level of UC and XOD in the serum,inhibit the activity of XOD in the liver tissue,and present a certain dose effect relationship.In this paper,fluorescence spectroscopy ? circular dichroism and ultraviolet spectrophotometry were used to study the interaction between 2 saponins in Ilex latifolia and XO.Latifolosides A ?Latifolosides D ?Kudinsoide A and Kudinsoide F can quench the endogenous fluorescence of XO,and did not affect the polar environment of amino acid residues around it.Latifolosides A and Latifolosides D can make XO endogenous fluorescence obviously quenched,the quenching form is combined quenching,but mainly in static.Kudinsoide A and Kudinsoide F can make XO endogenous fluorescence obviously quenched,the quenching form is static,there are one binding site between all four compounds and XO.Thermodynamic studies have shown that the action of the Latifolosides A and Latifolosides D with XO is entropy-driven endothermic,the main force is hydrophobic interaction,Kudinsoide A and Kudinsoide F with XO is enthalpy driven exothermic,the main force is hydrogen bond and van Edward force.By analyzing the structure and binding ability of compounds,the results show that,kudinsoide saponin with more active hydroxyl groups has stronger ability to bind than Latifolosides saponin,the protein conformation changed significantly.because there are more active hydroxyl groups in the structure.