Isolation And Identification Of Bond Hypotensive Active Ingredients Present In Coreopsis Tinctoria Nutt.

Coreopsis tinctoria Nutt has a significant effect in lowering blood pressure and is widelyused in folk, It is difficult to directly extract the bound compounds from Coreopsis tinctoria Nutt.owing to their binding to the cell wall material by covalent bond, an alkaline digestion method inthe current study was used to release the bound compounds and optimized the digestionparameters, on this basis, the digestion product were extracted using several different solvents forscreening the optimal solvent, a crude extract was therefore obtained. The pure compounds wereisolated from the crude extract by open column silica gel column chromatography and SephedexLH-20gel column chromatography. Their antioxidant activities were evaluated by DPPH andABTS methods, respectively. And then compounds was evaluated by ACE enzyme inhibitiontest.The results showed that:(1)the optimum alkaline degradation temperature is50℃, the time2h, the NaOHconcentration2mol·L-1, and the optimum solvent for bound flavonoids is n-butanol. On this basis,the response surface design was testing, Optimal process parameters is that alkaline degradationtemperature is56℃，the NaOH concentration1.65mol·L-1，the time2h，The total flavonoids wasreached to23.067mg·g-1. Quadratic regression equation: Y=-27.6734＋1.5389A＋6.9080B＋1.3468C-0.0663AB＋0.0435AC+0.0525BC-0.0134A2-0.9845B2-0.9570C2。(2)Eight pure compounds were isolated from the crude extract and their chemical structureswere elucidated as4,6-dyhydroxy-2-[6-hydroxy-1,5-dimethyl-4-hexylene]-5-benzyl-β-D-glucopyranoside、 okanin-4’-O-β-D-glucopyranoside、 vanilline、3’,4’,7,8-tetrahydroxyflavanone、3’,4’,7,8-tetrahydroxyflavone、2-phenylethyl-β-D-glucopyranoside、trans-Linalool-3,6-oxide-β-D-glucopyranoside and methyl coumarater by nuclear magnetic resonance (NMR) andelectro-spray ionization mass spectrometry (ESIMS).(3)The antioxidant test results shown that compounds1、2、4、5have a strong antioxidantcapacity. The IC50values of compounds1、2、4and5in DPPH analysis are92.21umol·L-1、17.29umol·L-1、70.09umol·L-1�'�50.07umol·L-1, respectively, while the IC50Values in ABTS analysisare43.06umol·L-1、22.86umol·L-1、33.40umol·L-1�'�32.52umol·L-1, respectively.(4) The ACE enzyme inhibition test results shown that compounds2、4、5have a strong ACEenzyme inhibition capacity. The IC50values of compounds2、4and5in ACE enzyme inhibitionanalysis are175.18umol·L-1、230.60umol·L-1�'�212.71umol·L-1.