A new lignan glycoside, named （7S,8R,8＇R）-（-）-lariciresinol-9-O-a-L-rhamnopyranosyl （1-2） 13-D-glucopyranoside （1）,was isolated from the ethanol extract ofPilea cavaleriei Levi subsp, cavaleriei, together wit...A new lignan glycoside, named （7S,8R,8＇R）-（-）-lariciresinol-9-O-a-L-rhamnopyranosyl （1-2） 13-D-glucopyranoside （1）,was isolated from the ethanol extract ofPilea cavaleriei Levi subsp, cavaleriei, together with 17 known lignans （2-18）. The structuresof these compounds were elucidated by extensive spectroscopic analysis, including 1D NMR, 2D NMR and HR-ESI-MS.All the compounds were obtained from the genus Pilea for the first time.展开更多
[Objectives] To study the chemical constituents of Pilea sinofasciata C. J. Chen. [Methods] Column chromatography,such as silica gel,Sephadex LH-20 and preparative HPLC were used to isolate and purify the compounds. S...[Objectives] To study the chemical constituents of Pilea sinofasciata C. J. Chen. [Methods] Column chromatography,such as silica gel,Sephadex LH-20 and preparative HPLC were used to isolate and purify the compounds. Spectroscopic methods like MS,1H NMR and^(13)C NMR and physical constants were used to elucidate their structure. [Results]Ninteen compounds were isolated from 95% ethanol extracts of Pilea sinofasciata C. J. Chen,including α-tocopherol(1),stigmasterol(2),epihernandulcin(3),hernandulcin(4),benzoic acid(5),ethyl linolenate(6),ethyl hexadecanoate(7),α-amyrin(8),palmitic acid(9),behenic acid(10),adenosine(11),indole-3-carboxylic acid(12),protocatechuate(13),gallic acid(14),betulinic acid(15),oleanolic acid(16),potassium nitrate(17),diosmetin7-O-β-D-glucopyranoside( 18),3-O-β-D-xylopyranosyl(1→2)-β-D-glucopyranosyl-28-O-β-D-glucopyranosyl oleanolic acid(19). [Conclusions] All of the compounds were isolated from the plant for the first time.展开更多
Six phenolic compounds namely,quercetin-3-O-rutinoside(1),3-O-caffeoylquinic acid(2),luteolin-7-O-glucoside(3),apigenin-7-O-rutinoside(4),apigenin-7-O-b-D-glucopyranoside(5)and quercetin(6)were isolated from the whole...Six phenolic compounds namely,quercetin-3-O-rutinoside(1),3-O-caffeoylquinic acid(2),luteolin-7-O-glucoside(3),apigenin-7-O-rutinoside(4),apigenin-7-O-b-D-glucopyranoside(5)and quercetin(6)were isolated from the whole plant of Pilea microphylla using conventional opensilica gel column chromatography and preparative HPLC.Further,these compounds were characterized by 1D,2D NMR techniques and high-resolution LC–MS.Compounds 1–3 and 6 exhibited significant antioxidant potential in scavenging free radicals such as DPPH,ABTS and SOD with IC_(50) of 3.3–20.4 mmol/L.The same compounds also prevented lipid peroxidation with IC_(50) of 10.4–32.2 mmol/L.The compounds also significantly prevented the Fenton reagent-induced calf thymus DNA damage.Pre-treatment with compounds 1–3 and 6 in V79 cells attenuated radiation-induced formation of reactive oxygen species,lipid peroxidation,cytotoxicity and DNA damage,correlating the antioxidant activity of polyphenols with their radioprotective effects.Compounds 1,3 and 6 significantly inhibited lipid peroxidation,presumably due to 30,40-catechol ortho-dihydroxy moiety in the B-ring,which has a strong affinity for phospholipid membranes.Oxidation of flavonoids,with catechol structure on B-ring,yields a fairly stable ortho-semiquinone radical by facilitating electron delocalization,which is involved in antioxidant mechanism.Hence,the flavonoid structure,number and location of hydroxyl groups together determine the antioxidant and radioprotection mechanism.展开更多
文摘A new lignan glycoside, named （7S,8R,8＇R）-（-）-lariciresinol-9-O-a-L-rhamnopyranosyl （1-2） 13-D-glucopyranoside （1）,was isolated from the ethanol extract ofPilea cavaleriei Levi subsp, cavaleriei, together with 17 known lignans （2-18）. The structuresof these compounds were elucidated by extensive spectroscopic analysis, including 1D NMR, 2D NMR and HR-ESI-MS.All the compounds were obtained from the genus Pilea for the first time.
基金Supported by Innovative Common Key Technology Research and Demonstration Project on Zhuang Medicine(Gui Ke Zhong 1355001-4,14124002-11)Guangxi Natural Science Foundation(2014GXNSFBA118142)+1 种基金Independent Research Project of Guangxi Key Laboratory of Traditional Chinese Medicine Quality Standards(Gui Zhong Zhong Zi 201408)Open Research Project of Guangxi Key laboratory of Chinese Medicine Efficacy Research(14-045-12-K3)
文摘[Objectives] To study the chemical constituents of Pilea sinofasciata C. J. Chen. [Methods] Column chromatography,such as silica gel,Sephadex LH-20 and preparative HPLC were used to isolate and purify the compounds. Spectroscopic methods like MS,1H NMR and^(13)C NMR and physical constants were used to elucidate their structure. [Results]Ninteen compounds were isolated from 95% ethanol extracts of Pilea sinofasciata C. J. Chen,including α-tocopherol(1),stigmasterol(2),epihernandulcin(3),hernandulcin(4),benzoic acid(5),ethyl linolenate(6),ethyl hexadecanoate(7),α-amyrin(8),palmitic acid(9),behenic acid(10),adenosine(11),indole-3-carboxylic acid(12),protocatechuate(13),gallic acid(14),betulinic acid(15),oleanolic acid(16),potassium nitrate(17),diosmetin7-O-β-D-glucopyranoside( 18),3-O-β-D-xylopyranosyl(1→2)-β-D-glucopyranosyl-28-O-β-D-glucopyranosyl oleanolic acid(19). [Conclusions] All of the compounds were isolated from the plant for the first time.
基金supported by a Grant Vide No.2007/37/53/BRNS from the Board of Research and Nuclear Sciences,Department of Atomic Energy,Government of India.
文摘Six phenolic compounds namely,quercetin-3-O-rutinoside(1),3-O-caffeoylquinic acid(2),luteolin-7-O-glucoside(3),apigenin-7-O-rutinoside(4),apigenin-7-O-b-D-glucopyranoside(5)and quercetin(6)were isolated from the whole plant of Pilea microphylla using conventional opensilica gel column chromatography and preparative HPLC.Further,these compounds were characterized by 1D,2D NMR techniques and high-resolution LC–MS.Compounds 1–3 and 6 exhibited significant antioxidant potential in scavenging free radicals such as DPPH,ABTS and SOD with IC_(50) of 3.3–20.4 mmol/L.The same compounds also prevented lipid peroxidation with IC_(50) of 10.4–32.2 mmol/L.The compounds also significantly prevented the Fenton reagent-induced calf thymus DNA damage.Pre-treatment with compounds 1–3 and 6 in V79 cells attenuated radiation-induced formation of reactive oxygen species,lipid peroxidation,cytotoxicity and DNA damage,correlating the antioxidant activity of polyphenols with their radioprotective effects.Compounds 1,3 and 6 significantly inhibited lipid peroxidation,presumably due to 30,40-catechol ortho-dihydroxy moiety in the B-ring,which has a strong affinity for phospholipid membranes.Oxidation of flavonoids,with catechol structure on B-ring,yields a fairly stable ortho-semiquinone radical by facilitating electron delocalization,which is involved in antioxidant mechanism.Hence,the flavonoid structure,number and location of hydroxyl groups together determine the antioxidant and radioprotection mechanism.
