| Apocynum Venetum Tea,which is also known as wild hemp and oleander hemp,can be divided into two kinds,kenaf and white linen.Apocynum Venetum Tea is a kind of apocynaceae,perennial and herbaceous plant.Apocynum venetum tea has a long history as Chinese traditional food and it contains a variety of active compositions,such as flavonoids,phenolic acid,cerebroside,polyphenol etc.Among them,some compositions have the antioxidant,anti-inflammatory,anti-cancer,lower blood pressure and fall hematic properties.Recent work has demonstrated that apocynum venetum tea has high edible and medicinal value,such as it can be used to reduce blood pressure and fall hematic.Chemical compositions of apocynum venetum tea were divided into three types:the free one,soluble one and the unsolvable one.The current study of combination type compounds has not been reported yet.In this study,the combination type compounds in apocynum venetum tea were isolated and identified.The biological activities of these compounds were evaluated preliminarily.On the basis of single factor experiments,the response surface was introduced to optimize the conditions of alkaline hydrolysis for bound compounds apocynum venetum tea with the polyphenol content as the index.The optimum parameters are:digestion time of 63mins,digestion temperature of 60.5 ?,the ratio of solvent to solid of 15 and alkaline concentration of 4.2 mol/L.Removal the free compounds apocynum venetum tea by organic solvent,then the rema ining residue was digested under the optimum conditions,and the degradation solution was extracted by organic solvent and concentrated to get the crude extracts,which was rich in b ound compounds.The crude extracts were separated by various column chromatography m ethods to obtain 11 compounds.The structures of these compounds were identified by mode rn spectroscopic techniques and compared with the literature data.11 bound compounds wer e identified to besyringic:(1)(-)-Epicatechinloliolide,(2)(-)-syringaresinol-4-O-?-D-glucopy rano-side,(3)benzene methyl glucoside,(4)7-monogalactosyl diacylglycerol,(5)7-diethylen e triamine-3-on-9-O-b-D-pyran glycosidase,(6)quercetin-3-O-glucopyranoside,(7)kaempfe rol-3-O-?-D-glucopyranoside,(8)1,2,3'",1-acetyl-2-palmitoyl-3-O-[?-D-galactopyranosyl]-(1"'-6"')-O-[?-D-galactopyranosyl]Glycerol,(9)1,2,3"'1-acetyl-2-cetylic acid-3-O-[?-D-galactose]-(1'"-6"')-O-[?-D-galactose]glycerol,(10)glyceryl dioleate,(11)3-hexenyl-1-O-?-D-glycoside;Among them,compound 5 and compound 8 are new compounds.DPPH,ABTS radical scavenging and FRAP reduction of iron ions method were used to evaluate the antioxidant activities of 11 compounds.The result shows that:Chemical compound I has the high DPPH radical scavenging antioxidative activity and the IC50 is 45.62?M.The radical scavenging activities of compounds 1 are higher than that of VE.The left bound compounds do not have the DPPH.Chemical compound?has the high ABTS radical scavenging antioxidative activity and the IC50 is 56.03 ?W.The radical scavenging activities of compounds 7 are higher than that of VE.Chemical compounds 7 and 8 have the highest FRAP reduction of ion activity.The FRAP of compound 7 is 0.1901 mM,and the FRAP of compound 8 is 0.1731 mM,higher than that of FRAP.The significance of this study lies in the extraction and separation of the bound compounds,which were less reported previously.We found two new compounds and give them the name.We also use one-dimensional and two-dimensional nuclear magnetic resonance spectroscopy and other modern techniques for the identification of its structure,and study their activity. |
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