Studies On Chemical Constituents And Antioxidant Of The Different Parts From Polygonum Viviparum

Objective:In order to improve the quality evaluation and accelerate resource development of Polygonum viviparum（PV）.The components and antioxidants of different parts from PV（roots,fruits,and leaves）were analyzed by high performance liquid chromatography-mass spectrometry（HPLC-MS）method and on-line antioxidant screening method.Methods:（1）Analysis of components in different parts from PV by online extraction HPLC-MS:The mixture of sample and acid-washed diatomite were placed in an online extraction tank and extracted by mobile phase at25℃.The separation was performed on Zorbax SB-AQ（4.6 mm×150 mm,5μm）column with gradient elution（0.2%acetic acid-acetonitrile）at 0.8m L/min.The detection wavelength was set at 254 nm.The MS in negative ion mode was adopted for identification of components.（2）Analysis of the antioxidant activity of different parts from PV by off-line antioxidant assay:2,2’-azino-bis-（3-ethylbenzothiozoline-6-sulfonic acid）（ABTS）assay,1,1-diphenyl-2-picrylhydrazyl（DPPH）assay,and iron ion reducing/antioxidant power（FRAP）assay were carried out.（3）Analysis of the antioxidants in different parts from PV by on-line HPLC antioxidant screening method:The samples were prepared by ultrasonic extraction.0.2 g plant sample was extracted with 4 m L of 50%methanol for 10 min.Then the sample solution was reacted with FRAP（1:3）for 6 min.The separation was performed on Poroshell 120 EC-C₁₈（150mm×4.6 mm,2.7μm）column.The 0.1%formic acid-acetonitrile was used as the mobile phase with gradient elution,and the flow rate was 1 m L/min.The column temperature was 25℃,and detection wavelength was set at340 nm.The MS was detected in negative ion mode.Results:（1）Analysis of chemical constituents from PV:A total of 23chromatographic peaks were found in PV samples,and 17 of them were identified.There are 7 common constituents of the roots,fruits and leaves（gallic acid,neochlorogenic acid,chlorogenic acid,quercetin-3-O-glucuronide,rutin,isoquercitrin and catechin）.Three other constituents were found from the roots（quercetin-4’-O-glucoside is unique compound,gallic acid hexoside and gallic acid hexoside isomers are only existed in to roots and fruits）;three other constituents were found from the fruits（caffeic acid is unique compound,gallic acid hexoside and gallic acid hexoside isomers are only existed in roots and fruits）;meanwhile six particular constituents were identified from the leaves（hyperoside,quercetin-3-O-vicianoside,rutin isomer,kaempferol-3-O-glucuronide,baicalin and hispidulin-7-O-glucuronide）.（2）Analysis of antioxidant activity of PV extracts:The results of ABTS assay showed that the 50%inhibition concentration(IC₅₀)values of scavenging ABTS free radicals of roots,fruits,leaves and rutin were 0.0287±0.001 mg/m L,0.0631±0.003 mg/m L,0.0786±0.004 mg/m L,and 0.0681±0.003 mg/m L.The results of DPPH assay showed that the IC₅₀ values of scavenging DPPH free radicals of roots,fruits,leaves and rutin were 0.1175±0.005 mg/m L,0.3358±0.016 mg/m L,0.4333±0.021 mg/m L,and 0.2245±0.011 mg/m L.The results of FRAP assay showed that the FRAP values of the roots,fruits,leaves and rutin were 1.7568±0.012 mmol/L,1.0593±0.004 mmol/L,0.4959±0.003 mmol/L,and 0.5433±0.007 mmol/L.The three extracts from the different parts of PV showed good antioxidant activity,and their antioxidant capacity as follow:roots>fruits>leaves.（3）Screening of antioxidants from PV:A total of 19 antioxidants were found in PV samples,and 15 of them were identified.There are 7 common antioxidants in the roots,fruits,leaves（gallic acid,neochlorogenic acid,chlorogenic acid,quercetin-3-O-glucuronide,rutin,isoquercitrin and catechin）.Two other antioxidants were found from the roots（quercetin-4’-O-glucoside is unique antioxidants,gallic acid hexoside is only existed in roots and fruits）;two other antioxidants were found from the fruits（caffeic acid is unique antioxidants,gallic acid hexoside is only existed in roots and fruits）;meanwhile five exclusive antioxidants were identified from the leaves（hyperoside,quercetin-3-O-vicianoside,rutin isomer,kaempferol-3-O-glucuronide and baicalin）.Conclusion:The chemical research of PV shows that 17 constituents were identified from PV（10 from roots,10 from fruits and 13 from leaves）,and 7compounds were common constituents in the different parts of PV.We also prove that the three extracts from the different parts of PV showed good antioxidant activity.The antioxidant research of PV shows that15 antioxidants were identified from PV（9 from roots,9 from fruits and 12from leaves）,and 7 compounds were common antioxidants in the different parts of PV.