In the^(1)H NMR-guided fractionation of extracts from the edible mushroom Lactarius deliciosus,two new azulene-type sesquiterpenoids,7-isopropenyl-4-methyl-azulene-1-carboxylic acid(1)and 15-hydroxy-3,6-dihydrolactar...In the^(1)H NMR-guided fractionation of extracts from the edible mushroom Lactarius deliciosus,two new azulene-type sesquiterpenoids,7-isopropenyl-4-methyl-azulene-1-carboxylic acid(1)and 15-hydroxy-3,6-dihydrolactarazulene(2),together with seven known compounds were characterized.Their structures were determined on basis of spectroscopic evidence,as well as by comparing with literature data.Amongst the known metabolites,the^(13)C NMR assignment of 15-hydroxy-6,7-dihydrolactarazulene(3)is reported here for the first time.Moreover,7-acetyl-4-methylazulene-1-carbaldehyde(5)displayed a moderate antibacterial activity against Staphylococcus aureus.展开更多
A novel polyketide pigment （1） with the 4＇,10-coupled linkage between 1-naphthalenol and 1,4-anthraquinone, named rufoolivacin B together with the known analog rufoolivacin （2）, has been isolated from the fruitin...A novel polyketide pigment （1） with the 4＇,10-coupled linkage between 1-naphthalenol and 1,4-anthraquinone, named rufoolivacin B together with the known analog rufoolivacin （2）, has been isolated from the fruiting bodies of the Chinese toadstool Cortinarius rufo-olivaceus （basidiomycetes）. Their structures were characterized by means of analysis of spectroscopic methods, including 2D-NMR experiments and HR-ESI-MS.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
基金the Natural Science Foundation for a Chinese Government Scholarship Fund for Study Abroad(31470414,20140101126JC).
文摘In the^(1)H NMR-guided fractionation of extracts from the edible mushroom Lactarius deliciosus,two new azulene-type sesquiterpenoids,7-isopropenyl-4-methyl-azulene-1-carboxylic acid(1)and 15-hydroxy-3,6-dihydrolactarazulene(2),together with seven known compounds were characterized.Their structures were determined on basis of spectroscopic evidence,as well as by comparing with literature data.Amongst the known metabolites,the^(13)C NMR assignment of 15-hydroxy-6,7-dihydrolactarazulene(3)is reported here for the first time.Moreover,7-acetyl-4-methylazulene-1-carbaldehyde(5)displayed a moderate antibacterial activity against Staphylococcus aureus.
基金supported by the National Natural Science Foundation of China(No.30670221)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry of China and by the Program for New Century Excellent Talents in University(No.NCET-05-0852)supported by the National Financial Aid for Studying Abroad(No.2007103088)(J.-C.Q.)
文摘A novel polyketide pigment （1） with the 4＇,10-coupled linkage between 1-naphthalenol and 1,4-anthraquinone, named rufoolivacin B together with the known analog rufoolivacin （2）, has been isolated from the fruiting bodies of the Chinese toadstool Cortinarius rufo-olivaceus （basidiomycetes）. Their structures were characterized by means of analysis of spectroscopic methods, including 2D-NMR experiments and HR-ESI-MS.
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.
