One undescribedamide,pipermullesine A,twoundescribed isoquinoline alkaloids,pipermullesinesBand C,and six undescribed dipeptides,pipermullamides A–F,along with 28 known compounds,were isolated from the aerial parts o...One undescribedamide,pipermullesine A,twoundescribed isoquinoline alkaloids,pipermullesinesBand C,and six undescribed dipeptides,pipermullamides A–F,along with 28 known compounds,were isolated from the aerial parts of Piper mullesua.The structures of the undescribed compounds were elucidated based on the analysis of 1D and 2D NMR and MS data.Furthermore,the structures of pipermullesines A–Cwere confirmed by single crystal X-ray diffraction analysis.All isolates were evaluated for inhibitory activity against platelet aggregation induced by thrombin(IIa)or platelet-activating factor(PAF).(-)-Mangochinine,pellitorine,and(2E,4E)-N-isobutyl-2,4-dodecadienamide showed weak inhibitory activity against rabbit platelet aggregation induced by PAF,with IC_(50)values of 470.3μg/mL,614.9μg/mL,and 579.7μg/mL,respectively.展开更多
Two new 2H-pyran-2-one glucosides,cuscutarosides A(1)and B(2),and one new steroidal glucoside,7β-methoxy-β-sitosterol 3-O-β-glucopyranoside(3),together with 12 known compounds(4-15)were isolated from the whole plan...Two new 2H-pyran-2-one glucosides,cuscutarosides A(1)and B(2),and one new steroidal glucoside,7β-methoxy-β-sitosterol 3-O-β-glucopyranoside(3),together with 12 known compounds(4-15)were isolated from the whole plant of Cuscuta reflexa(Convolvulaceae)collected from Myanmar.The chemical structures of these new compounds were elucidated based on extensive spectroscopic analysis.The antiobesity activity of these isolates was evaluated using porcine pancreatic lipase(PPL),and the antiplatelet aggregation activity was screened using rabbit platelets induced by thrombin,platelet-activating factor(PAF),arachidonate(AA),or collagen.7β-Methoxy-β-sitosterol 3-O-β-glucopyranoside(3)showed weak PPL inhibitory activity.Cuscutaroside A(1),its acetylated derivative(1a),and scrophenoside B(8)showed weak inhibitory activity against rabbit platelet aggregation induced by collagen.Compound 1a also showed inhibitory activity against rabbit platelet aggregation induced by AA.展开更多
We aimed at reporting the chemical constituents and antimicrobial activities of Leea aequata L.,a traditional folk medicine used in Myanmar for the treatment of wounds and skin diseases.A new neolignan,(7S,8R)-9′-O-a...We aimed at reporting the chemical constituents and antimicrobial activities of Leea aequata L.,a traditional folk medicine used in Myanmar for the treatment of wounds and skin diseases.A new neolignan,(7S,8R)-9′-O-acetylcedrusin(1),a new lactam,(3S,4S)-4-chloro-3-hydroxypiperidin-2-one(2),along with 21 known compounds,including fve lignans(3-7),four favonoid glycosides(8-11),and others(12-23),were isolated from the ethanoic extract of the aerial parts of L.aequata.The structures of the new compounds were determined by NMR,MS,and ECD spectra.For all the antimicrobial tests of the 23 compounds,only 3,4,5-trihydroxybenzoic acid ethyl ester(17)showed weak inhibitory activities against Escherichia coli and Salmonella enterica subsp.enterica.展开更多
Five new 2-(2-phenylethyl)chromone derivatives,(5S,6R,7R,8S,7ʹR)-7ʹ-hydroxyagarotetrol(1),(5S,6R,7R,8S,7ʹS)-7ʹ-hydroxyagarotetrol(2),(6S,7S,8R)-2-[2-(4-methoxyphenyl)ethyl]-6,7,8-trihydroxy-5,6,7,8-tetrahydrochromone(...Five new 2-(2-phenylethyl)chromone derivatives,(5S,6R,7R,8S,7ʹR)-7ʹ-hydroxyagarotetrol(1),(5S,6R,7R,8S,7ʹS)-7ʹ-hydroxyagarotetrol(2),(6S,7S,8R)-2-[2-(4-methoxyphenyl)ethyl]-6,7,8-trihydroxy-5,6,7,8-tetrahydrochromone(3),(6S,7S,8R)-2-(2-phenylethyl)-6,7,8-trihydroxy-5,6,7,8-tetrahydrochromone(4),(5S,6R,7S,8R)-2-(2-phenylethyl)-5,6,7-trihydroxy-5,6,7,8-tetrahydro-8-[2-(2-phenylethyl)-7-methoxychromonyl-6-oxy]chromone(5),three new sesquiterpenoids,(4S,5S,7S,8S,10S,13R)-7,8,13-trihydroxyrotunda-1,11-dien-3-one(6),(4S,5S,7S,8S,10S,13S)-7,8,13-trihydroxyrotunda-1,11-dien-3-one(7),and(4R,5S,7S,8S,10S,13S)-7,8,13-trihydroxyrotunda-1,11-dien-3-one(8),along with 14 known compounds were isolated from the resinous heartwood of Aquilaria sinensis(Thymelaeaceae).The chemical structures of these new compounds were elucidated by 1D and 2D NMR and MS data,single-crystal X-ray diffraction analysis,and electronic circular dichroism(ECD)calculations.The neuroprotective activities of these isolates were evaluated using an in vitro model of rat adrenal pheochromocytoma(PC12)cell injury induced by corticosterone.At concentrations from 5 to 40μM,compounds 4 and 6,agarotetrol(9),and 6-hydroxy-2-(2-phenylethyl)chromone(17)showed significant protective activities against corticosterone-induced PC12 cell injury(P<0.001).展开更多
Bioassay-guided fractionation of the EtOH extract from the flowers of Aquilaria sinensis(Lour.)Spreng.(Thyme-laeaceae)led to the isolation of a new cucurbitane-type triterpenoid,aquilarolide A(1),along with five known...Bioassay-guided fractionation of the EtOH extract from the flowers of Aquilaria sinensis(Lour.)Spreng.(Thyme-laeaceae)led to the isolation of a new cucurbitane-type triterpenoid,aquilarolide A(1),along with five known compounds(2-6).The structure of 1 was elucidated by extensive 1D and 2D nuclear magnetic resonance(NMR)experiments and mass spectrometry(MS)data and theoretical calculations of its electronic circular dichroism(ECD)spectra.Aquilarolide A,cucurbitacin E(3),cucurbitacin B(4),and 7-hydroxy-6-methoxy-2-[2-(4-methoxyphenyl)ethyl]-4H-1-benzopyran-4-one(6)showed significant cytotoxicity against human lung adenocarcinoma SPC-A-1,human lung squamous cell carcinoma NCI-H520,human lung adenocarcinoma A549,and paclitaxel-resistant A549(A549/Taxol)cell lines.All four active compounds,with IC_(50) values ranging from 0.002 to 0.91μM,had better inhibitory activities against A549/Taxol cells than paclitaxel(IC_(50)=1.80μM).Among them,cucurbitacin E(IC_(50)=0.002μM)is the most active.Further studies are needed to evaluate their in vivo antitumor activities and to clarify their mechanisms.展开更多
Objective:To clarify the active constituents of the heartwoods of Caesalpinia sappan,a traditional Chinese medicine with the functions of promoting blood circulation(Huoxue in Chinese)and removing blood stasis(Quyu in...Objective:To clarify the active constituents of the heartwoods of Caesalpinia sappan,a traditional Chinese medicine with the functions of promoting blood circulation(Huoxue in Chinese)and removing blood stasis(Quyu in Chinese).Methods:The chemical constituents were isolated and purified by combination of silica gel and Sephadex LH-20 column chromatography,along with semipreparative HPLC.Their chemical structures were established by multiple spectroscopic methods and comparison with literature data.The in vitro antiplatelet aggregation activities were evaluated using mouse platelet induced by AYPGKF-NH2,a gold agonist of protease-activated receptor 4(PAR4).Results:Two new phenols,methyl 2-(4,4’,5’-trihydroxy-2’-(methoxymethyl)biphenyl-2-yloxy)acetate(1)and 1’-methylcaesalpin J(2),together with 24 known compounds(3-26),were isolated from the heartwoods of C.sappan.Among them,sappanchalcone(16)and brazilin(20)showed inhibitory activities against mouse platelet aggregation with IC50 values of 114.8μmol/L and 100.8μmol/L,respectively.Conclusion:Antiplatelet compounds from C.sappan targeting at PAR4 are reported for the first time.展开更多
Low carbon steel wires were prepared by two processes,serial drawing(SD)and reverse-direction drawing(RD).Effects of the two processes on microstructure and mechanical properties in steel wires were investigated by fi...Low carbon steel wires were prepared by two processes,serial drawing(SD)and reverse-direction drawing(RD).Effects of the two processes on microstructure and mechanical properties in steel wires were investigated by field emissio scanning electron microscopy,electron backscatter diffraction(EBSD),X-ray diffraction and transmission electron microscopy(TEM).Residual compressive stress and more low-angle grain boundaries were introduced into the steel wire by the RD.As a result,the RD wires exhibited a greater tensile strength when drawing strain s<1.18.The SD encouraged grain refinement and texture formation in the wire.The SD wires exhibited a smaller average width of the elongated ferrite grain and a higher intensity of(110)fiber texture at all drawing strains.Therefore,the SD wires showed a bit greater tensile strength and 20%greater torsion performance than the RD wires at c=2.51.TEM and EBSD analysis indicated that dislocation tangle was formed easily in RD wires,and it transformed into twist boundary.This twist boundary impeded the grain refinement in the RD wires,and there were still non-fibrous grains in the RD wires even after heavy drawing.展开更多
基金This work was funded by the Southeast Asia Biodiversity Research Institute,Chinese Academy of Sciences(Y4ZK111B01)the Natural Science Foundation of Yunnan Province,China(2011FZ205)+2 种基金the International Partneship Program of Chinese Academy of Sciences(153631KYSB20160004)the Key Laboratory of Ethnomedicine(Minzu University of China)of Ministry of Education of China(KLEM-ZZ201806)the National Natural Science Foundation of China(31761143001&31161140345).
文摘One undescribedamide,pipermullesine A,twoundescribed isoquinoline alkaloids,pipermullesinesBand C,and six undescribed dipeptides,pipermullamides A–F,along with 28 known compounds,were isolated from the aerial parts of Piper mullesua.The structures of the undescribed compounds were elucidated based on the analysis of 1D and 2D NMR and MS data.Furthermore,the structures of pipermullesines A–Cwere confirmed by single crystal X-ray diffraction analysis.All isolates were evaluated for inhibitory activity against platelet aggregation induced by thrombin(IIa)or platelet-activating factor(PAF).(-)-Mangochinine,pellitorine,and(2E,4E)-N-isobutyl-2,4-dodecadienamide showed weak inhibitory activity against rabbit platelet aggregation induced by PAF,with IC_(50)values of 470.3μg/mL,614.9μg/mL,and 579.7μg/mL,respectively.
基金supported by the Southeast Asia Biodiversity Research Institute,Chinese Academy of Sciences(Grant Nos.2015CASEABRIRG001 and Y4ZK111B01)the International Partnership Program of Chinese Academy of Sciences(Grant No.153631KYSB20160004)+2 种基金the National Natural Science Foundation of China(31960480)the Joint Special Project of Local Undergraduate Universities in Yunnan Province,China(Grant No.2018FH001-024)the Second Tibetan Plateau Scientific Expedition and Research(STEP)Program of Ministry of Science and Technology of the People’s Republic of China(Grant No.2019QZKK0502).
文摘Two new 2H-pyran-2-one glucosides,cuscutarosides A(1)and B(2),and one new steroidal glucoside,7β-methoxy-β-sitosterol 3-O-β-glucopyranoside(3),together with 12 known compounds(4-15)were isolated from the whole plant of Cuscuta reflexa(Convolvulaceae)collected from Myanmar.The chemical structures of these new compounds were elucidated based on extensive spectroscopic analysis.The antiobesity activity of these isolates was evaluated using porcine pancreatic lipase(PPL),and the antiplatelet aggregation activity was screened using rabbit platelets induced by thrombin,platelet-activating factor(PAF),arachidonate(AA),or collagen.7β-Methoxy-β-sitosterol 3-O-β-glucopyranoside(3)showed weak PPL inhibitory activity.Cuscutaroside A(1),its acetylated derivative(1a),and scrophenoside B(8)showed weak inhibitory activity against rabbit platelet aggregation induced by collagen.Compound 1a also showed inhibitory activity against rabbit platelet aggregation induced by AA.
基金supported by the Southeast Asia Biodiversity Research Institute,Chinese Academy of Sciences(Grant Nos.2015CASEABRIRG001 and Y4ZK111B01)the International Partnership Program of Chinese Academy of Sciences(153631KYSB20160004).
文摘We aimed at reporting the chemical constituents and antimicrobial activities of Leea aequata L.,a traditional folk medicine used in Myanmar for the treatment of wounds and skin diseases.A new neolignan,(7S,8R)-9′-O-acetylcedrusin(1),a new lactam,(3S,4S)-4-chloro-3-hydroxypiperidin-2-one(2),along with 21 known compounds,including fve lignans(3-7),four favonoid glycosides(8-11),and others(12-23),were isolated from the ethanoic extract of the aerial parts of L.aequata.The structures of the new compounds were determined by NMR,MS,and ECD spectra.For all the antimicrobial tests of the 23 compounds,only 3,4,5-trihydroxybenzoic acid ethyl ester(17)showed weak inhibitory activities against Escherichia coli and Salmonella enterica subsp.enterica.
基金supported by Beijing Sino-Science Aquilaria Technology Co.,Ltd.,Beijing,China (no.KET202101).
文摘Five new 2-(2-phenylethyl)chromone derivatives,(5S,6R,7R,8S,7ʹR)-7ʹ-hydroxyagarotetrol(1),(5S,6R,7R,8S,7ʹS)-7ʹ-hydroxyagarotetrol(2),(6S,7S,8R)-2-[2-(4-methoxyphenyl)ethyl]-6,7,8-trihydroxy-5,6,7,8-tetrahydrochromone(3),(6S,7S,8R)-2-(2-phenylethyl)-6,7,8-trihydroxy-5,6,7,8-tetrahydrochromone(4),(5S,6R,7S,8R)-2-(2-phenylethyl)-5,6,7-trihydroxy-5,6,7,8-tetrahydro-8-[2-(2-phenylethyl)-7-methoxychromonyl-6-oxy]chromone(5),three new sesquiterpenoids,(4S,5S,7S,8S,10S,13R)-7,8,13-trihydroxyrotunda-1,11-dien-3-one(6),(4S,5S,7S,8S,10S,13S)-7,8,13-trihydroxyrotunda-1,11-dien-3-one(7),and(4R,5S,7S,8S,10S,13S)-7,8,13-trihydroxyrotunda-1,11-dien-3-one(8),along with 14 known compounds were isolated from the resinous heartwood of Aquilaria sinensis(Thymelaeaceae).The chemical structures of these new compounds were elucidated by 1D and 2D NMR and MS data,single-crystal X-ray diffraction analysis,and electronic circular dichroism(ECD)calculations.The neuroprotective activities of these isolates were evaluated using an in vitro model of rat adrenal pheochromocytoma(PC12)cell injury induced by corticosterone.At concentrations from 5 to 40μM,compounds 4 and 6,agarotetrol(9),and 6-hydroxy-2-(2-phenylethyl)chromone(17)showed significant protective activities against corticosterone-induced PC12 cell injury(P<0.001).
基金Funding was provided by Beijing Sino-Science Aquilaria Technology Co.,Ltd.,Beijing,China (Grant No.KET202101).
文摘Bioassay-guided fractionation of the EtOH extract from the flowers of Aquilaria sinensis(Lour.)Spreng.(Thyme-laeaceae)led to the isolation of a new cucurbitane-type triterpenoid,aquilarolide A(1),along with five known compounds(2-6).The structure of 1 was elucidated by extensive 1D and 2D nuclear magnetic resonance(NMR)experiments and mass spectrometry(MS)data and theoretical calculations of its electronic circular dichroism(ECD)spectra.Aquilarolide A,cucurbitacin E(3),cucurbitacin B(4),and 7-hydroxy-6-methoxy-2-[2-(4-methoxyphenyl)ethyl]-4H-1-benzopyran-4-one(6)showed significant cytotoxicity against human lung adenocarcinoma SPC-A-1,human lung squamous cell carcinoma NCI-H520,human lung adenocarcinoma A549,and paclitaxel-resistant A549(A549/Taxol)cell lines.All four active compounds,with IC_(50) values ranging from 0.002 to 0.91μM,had better inhibitory activities against A549/Taxol cells than paclitaxel(IC_(50)=1.80μM).Among them,cucurbitacin E(IC_(50)=0.002μM)is the most active.Further studies are needed to evaluate their in vivo antitumor activities and to clarify their mechanisms.
基金supported by the International Partnership Program of Chinese Academy of Sciences(153631KYSB20160004)the Southeast Asia Biodiversity Research Institute,Chinese Academy of Sciences(Y4ZK111B01).
文摘Objective:To clarify the active constituents of the heartwoods of Caesalpinia sappan,a traditional Chinese medicine with the functions of promoting blood circulation(Huoxue in Chinese)and removing blood stasis(Quyu in Chinese).Methods:The chemical constituents were isolated and purified by combination of silica gel and Sephadex LH-20 column chromatography,along with semipreparative HPLC.Their chemical structures were established by multiple spectroscopic methods and comparison with literature data.The in vitro antiplatelet aggregation activities were evaluated using mouse platelet induced by AYPGKF-NH2,a gold agonist of protease-activated receptor 4(PAR4).Results:Two new phenols,methyl 2-(4,4’,5’-trihydroxy-2’-(methoxymethyl)biphenyl-2-yloxy)acetate(1)and 1’-methylcaesalpin J(2),together with 24 known compounds(3-26),were isolated from the heartwoods of C.sappan.Among them,sappanchalcone(16)and brazilin(20)showed inhibitory activities against mouse platelet aggregation with IC50 values of 114.8μmol/L and 100.8μmol/L,respectively.Conclusion:Antiplatelet compounds from C.sappan targeting at PAR4 are reported for the first time.
基金This work is supported by the National Natural Science Foundation of China(Grant No.51371050)Special Talent Program of Jiangsu Province(2015-XCL-004)+2 种基金the Industry・University Strategic Research Fund of Jiangsu Province(BY2016076-08)The study is also partly supported by the Science and Technology Advancement Program of Jiangsu Province(Grant No.BA2017112)L.C.Zhou appreciates the support provided by Fundamental Research Funds for the Central Universities and the Scientific Research Foundation of the Graduate School of Southeast University(YBJJ1674).
文摘Low carbon steel wires were prepared by two processes,serial drawing(SD)and reverse-direction drawing(RD).Effects of the two processes on microstructure and mechanical properties in steel wires were investigated by field emissio scanning electron microscopy,electron backscatter diffraction(EBSD),X-ray diffraction and transmission electron microscopy(TEM).Residual compressive stress and more low-angle grain boundaries were introduced into the steel wire by the RD.As a result,the RD wires exhibited a greater tensile strength when drawing strain s<1.18.The SD encouraged grain refinement and texture formation in the wire.The SD wires exhibited a smaller average width of the elongated ferrite grain and a higher intensity of(110)fiber texture at all drawing strains.Therefore,the SD wires showed a bit greater tensile strength and 20%greater torsion performance than the RD wires at c=2.51.TEM and EBSD analysis indicated that dislocation tangle was formed easily in RD wires,and it transformed into twist boundary.This twist boundary impeded the grain refinement in the RD wires,and there were still non-fibrous grains in the RD wires even after heavy drawing.