Two novel xanthones, 1,6-dihydroxy-4,5-dimethoxyxanthone (1) and 1,5,6-trihydroxy-7,8-di(3-methyl-2-butenyl)-6',6'-dimethylpyrano(2',3':3,4)xanthone (2) were isolated from the bark of Garcinia xanthochymu...Two novel xanthones, 1,6-dihydroxy-4,5-dimethoxyxanthone (1) and 1,5,6-trihydroxy-7,8-di(3-methyl-2-butenyl)-6',6'-dimethylpyrano(2',3':3,4)xanthone (2) were isolated from the bark of Garcinia xanthochymus by normal phase and reverse phase silica gel column chromatography. Their structures were elucidated by spectroscopic methods, especially 2D-NMR techniques.展开更多
AIM:To investigate the growth inhibitory mechanism of four caged xanthones from Garcinia hanburyi in cholangiocarcinoma(CCA) KKU-100 and KKU-M156 cells.METHODS:Four caged xanthones,selected on the basis of their antic...AIM:To investigate the growth inhibitory mechanism of four caged xanthones from Garcinia hanburyi in cholangiocarcinoma(CCA) KKU-100 and KKU-M156 cells.METHODS:Four caged xanthones,selected on the basis of their anticancer potency and chemical structure diversities(i.e.isomorellin,isomorellinol,forbesione and gambogic acid) were used in this study.Growth inhibition of these caged xanthones was determined using the sulforhodamine B assay.Induction of apoptosis was assessed by observing cell morphology,ethidium bromide and acridine orange staining and DNA fragmentation assay.Levels of apoptotic-related gene and protein expressions were determined by a real-time reverse transcriptase polymerase chain reaction and Western blotting analysis,respectively.RESULTS:The compounds were found to inhibit growth of both cell lines in a dose-dependent manner and also showed selective cytotoxicity against the cancer cells when compared with normal peripheral blood mononuclear cells.Growth suppression by these compounds was due to apoptosis,as evidenced by the cell morphological changes,chromatin condensation,nuclear fragmentation,and DNA ladder formation.At the molecular level,these compounds induced down-regulation of Bcl-2 and survivin proteins with up-regulation of Bax and apoptosisinducing factor proteins,leading to the activation of caspase-9 and-3 and DNA fragmentation.The functional group variations did not appear to affect the anticancer activity with regard to the two CCA cell lines;however,at a mechanistic level,isomorellinol exhibited the highest potency in increasing the Bax/Bcl-2 protein expression ratio(120 and 41.4 for KKU-100 and KKU-M156,respectively) and in decreasing survivin protein expression(0.01 fold as compared to control cells in both cell lines).Other activities at the molecular level indicate that functional groups on the prenyl side chain may be important.CONCLUSION:Our findings for the first time demonstrate that four caged xanthones induce apoptosis in CCA cells which is mediated through a mitochondriadependent signaling pathway.展开更多
A capillary electrophoresis (CE) method has been firstly used for the separation of the therapeutically important xanthones from Securidaca inappendiculata. The separation of the nine xanthones was systematically opt...A capillary electrophoresis (CE) method has been firstly used for the separation of the therapeutically important xanthones from Securidaca inappendiculata. The separation of the nine xanthones was systematically optimized with respect to pH, concentration of running buffers, addition of sulfated b-CD, applied voltage and column temperature. Baseline separation was achieved for the nine xanthones in less than 15 minutes using a background electrolyte consisting of 200 mmol/L borate (pH 9.5) and 10 mmol/L sulfated b-CD.展开更多
A microemulsion electrokinetic chromatography method has been firstly used for the separation of the therapeutically important xanthones from Securidaca inappendiculata. The separation of the nine xanthones was syste...A microemulsion electrokinetic chromatography method has been firstly used for the separation of the therapeutically important xanthones from Securidaca inappendiculata. The separation of the nine xanthones was systematically optimized with respect to pH, composition of microemulsion, addition of cyclodextrins, applied voltage and column temperature. Baseline separation was successfully achieved for the nine xanthones, which was also compared with that by micellar electrokinetic chromatography.展开更多
Introduction Xanthones are secondary metabolites commonly occurring in a few higher plant families, fungi and lichen. Their high taxonomic value in such families and their pharmacological properties, including in vitr...Introduction Xanthones are secondary metabolites commonly occurring in a few higher plant families, fungi and lichen. Their high taxonomic value in such families and their pharmacological properties, including in vitro cytotoxicity, in vivo antitumour activity, antifungal, antibacterial, antiinflammatory properties and aldose reductase inhibitory activity have provoked great interest. The discovery of the antidiabetic activity of some axnthones' from Swertiaceae has prompted us to undertake a more broadly search for novel xanthones from plants of Polygalaceae. The phytochemical investigation has not been performed on this plant up to now. Herein we report the isolation and structure elucidation of two new xanthones ( compounds 1 and 2 ) and three known xanthones (compound 3, 4 and 5 ).展开更多
The thermodynamic properties of dibenzofurans (DFs), xanthones (XTs) and an-thraquinones (AQs) with one and two positions substituted with hydroxyls in the ideal gas state at 298.15 K and 1.013×10^5 pa were...The thermodynamic properties of dibenzofurans (DFs), xanthones (XTs) and an-thraquinones (AQs) with one and two positions substituted with hydroxyls in the ideal gas state at 298.15 K and 1.013×10^5 pa were calculated at the B3LYP/6-311G^* level using Gaussian 03 program. The isodesmic reactions were designed to calculate the standard free energy of formation (△fG^θ). Three types of hydrogen bonds exist in the three kinds of chemicals and their bond energies were ascertained as 7-15, 15-23 and 49-58 kJ·mo1^-1 respectively by comparing the △fG^θ values. Electronic density topology analysis was applied to validate the strength of bond.展开更多
Thirteen xanthones were isolated from L.rotatum,which were established as l,8-dihydroxy-3,4,5-trimethoxyxanthone(1);l-hydroxy-3异,8-trimethoxyxanthone(2);8-hydroxy-l,3?5-trimethoxyxaiithone(3);l-hydroxy-3,4,5-trimetho...Thirteen xanthones were isolated from L.rotatum,which were established as l,8-dihydroxy-3,4,5-trimethoxyxanthone(1);l-hydroxy-3异,8-trimethoxyxanthone(2);8-hydroxy-l,3?5-trimethoxyxaiithone(3);l-hydroxy-3,4,5-trimethoxyxanthone(4);l-hydroxy-3,5,8-trimethoxyxanthone(5);l,4,8-trihydroxy-5,6-dimethoxyxanthone(6);l,3,8-trihydroxy-4,7-dimethoxyxanthone(;7)l,8-dihydroxy-3,7-dimethoxyxanthone(8);l-hydroxy-3,5-dimethoxyxanthone(9);l-hydroxy-2,3,4,5-tetramethoxyxanthone(;10)l-hydroxy-2,3,4,7-tetramethoxyxanthone(11);l,7-dihydroxy-3,8-dimethoxyxanthone(12);rel-l,3,5,8-tetrahydroxy-2,4,6,7-tetrahydroxanthen-9-one(13).Compounds 4,6,7,9,10,11,12 and 13 are reported for the first time from Lomatogonium.Furthermore,the activity of xanthones was assessed.展开更多
In order to study the relationship between biological and pharmacological activities with their structures, a series of tri- and tetra-oxygenated xanthones including 1-hydroxyl-2,3,4,7- tetramethoxy xanthone 1, 1-hydr...In order to study the relationship between biological and pharmacological activities with their structures, a series of tri- and tetra-oxygenated xanthones including 1-hydroxyl-2,3,4,7- tetramethoxy xanthone 1, 1-hydroxyl-2,3,4,5-tetramethoxyl xanthone 2, 1-hydroxyl-3,5-dimethoxy- xanthone 3, 1,8-dihydroxyl-3,5-dimethoxyl xanthone 4 and 1,5,8-trihydroxyl-3-methoxy xanthone 5 have been isolated from Swertia chirayita. Their structures were established on the basis of spectral and chemical evidences. The crystal structure of 5 was also investigated by single-crystal X-ray diffraction analysis. It crystallizes in the triclinic system, space group P?with a = 7.1540(10), b = 7.520(2), c = 10.671(2) , V = 562.7(2) 3 , α = 86.50(3), β = 80.06(3) , γ = 85.00(3), Z = 2, Dc = 1.618 g/m3, R = 0.0405, wR = 0.1028 and F(000) = 284. The molecular structure of 5 is nearly planar and four substituents are much closer to the plane. Compound 5 contains three intermolecular hydro- gen bonds. A recent study shows that phenolic hydroxyls in xanthones are the main active groups capable of scavenging OH and O2.展开更多
The thermodynamic properties of xanthone(XTH) and 135 polybrominated xanthones(PBXTHs) in the standard state have been calculated at the B3LYP/6-31G* level using Gaussian 03 program.The isodesmic reactions were d...The thermodynamic properties of xanthone(XTH) and 135 polybrominated xanthones(PBXTHs) in the standard state have been calculated at the B3LYP/6-31G* level using Gaussian 03 program.The isodesmic reactions were designed to calculate the standard enthalpy of formation(△fHθ) and standard free energy of formation(△fGθ) of PBXTH congeners.The relations of these thermodynamic parameters with the number and position of Br atom substitution(NPBS) were discussed,and it was found that there exist high correlation between thermodynamic parameters(entropy(Sθ),△fHθ and △fGθ) and NPBS.According to the relative magnitude of their △fGθ,the relative stability order of PBXTH congeners was theoretically proposed.The relative rate constants of formation reactions of PBXTH congeners were calculated,Moreover,the values of molar heat capacity at constant pressure(Cp,m) from 200 to 1000 K for PBXTH congeners were also calculated,and the temperature dependence relation of them was obtained,suggesting very good relationships between Cp,m and temperature(T,T^1 and T^2) for almost all PBXTH congeners.展开更多
The linearity, stability, accuracy and inter-day precisions of the assay method were evaluated in methanolic aerial-part extracts of Paepalanthus giganteus and Syngontnhus nitens from the Eriocaulaceae family. Their s...The linearity, stability, accuracy and inter-day precisions of the assay method were evaluated in methanolic aerial-part extracts of Paepalanthus giganteus and Syngontnhus nitens from the Eriocaulaceae family. Their small capitulae hinder morphological analysis, and thus complicate taxonomic studies of these species, which present anti-ulcer, antimutagenic and antioxidant activities. Taxonomic studies of these plants revealed that the Paepalanthus genus presents flavonols and naphthopyranones while the Syngontnhus genus has flavone and xanthone as majority compounds. The prepared samples were analyzed quantitatively by High Performance Liquid Chromatography with PDA detection for the presence of quercetin, luteolin, 3,6-dimethoxy-1,5,7-tri-hydroxyxanthone and paepalantine. The substances were recovered from these samples at rates from 98.01 to 99.99%. The coefficient of variation in the quantitative analysis of the sample com- pounds was under 5%. The linearity of the method was determined by linear regression. The analysis of the samples spiked with known amounts of analyte demonstrated that the response was proportional to the concentrations of the sam- ples with re-spective determination coefficients of r2 = 0.9999 (luteolin and 3,6-dimethoxy-1,5,7-tri-hydroxyxanthone) and r2 = 0.9998 (quercetin and paepalantine) for the linear range of the analytical calibration curves of the samples. The detection limits were 0.07 μg?mL–1 for quercetin and luteolin, 0.06 μg?mL–1 for 3,6-dimethoxy-1,5,7-tri-hydroxyxanthone and 0.10 μg?mL–1 for paepalantine. The quantification limits were 0.23 μg?mL–1 for quercetin and luteolin, 0.20 μg?mL–1 for 3,6-dimethoxy-1,5,7-tri-hydroxyxanthone and 0.33 μg?mL–1 for paepalantine by LC. The method was considered sen- sitive for quantification of the quercetin, luteolin, 3,6-dimethoxy-1,5,7-tri-hydroxyxanthone and paepalantine in plant samples.展开更多
AIM: To study the chemical constituents of Lomatogonium carinthiacum(Wulfen) Rchb. METHOD: The CHCl3-soluble fraction was separated by chromatography and the structures of the new compounds were elucidated by spectral...AIM: To study the chemical constituents of Lomatogonium carinthiacum(Wulfen) Rchb. METHOD: The CHCl3-soluble fraction was separated by chromatography and the structures of the new compounds were elucidated by spectral experiments. RESULTS: Two new xanthones, 1, 8-dihydroxy-4, 5-dimethoxy-6, 7-methylenedioxyxanthone(1), 1, 4, 8-trimethoxyxanthone-6-O-β-D-glucoronyl-(1→6)O-β-D-glucoside(2) were isolated from the whole plant of Lomatogonium carinthiacum. CONCLUSION: Compounds 1 and 2 are new natural products.展开更多
Elodexanthones A—J (1—10), two pairs of rearranged isoprenylated xanthone enantiomers with an unprecedent 6/6/5/6 tetracyclic core (1—2) along with seven new isoprenylated xanthones (3—9) and a pair of phenylpropa...Elodexanthones A—J (1—10), two pairs of rearranged isoprenylated xanthone enantiomers with an unprecedent 6/6/5/6 tetracyclic core (1—2) along with seven new isoprenylated xanthones (3—9) and a pair of phenylpropanoid xanthones (10), were purified and enantio-separated from the whole plant of Hypericum elodeoides. Their structures including absolute configurations were characterized by the comprehensive analysis of NMR, HRESIMS, NMR calculations, and ECD calculations. Through Bayer-Villiger oxidation, Claisen condensation and electrophilic addition, the rearranged skeletons of elodexanthones A—B (1—2) were generated from isoprenylated xanthone precursors. The bioactivities evaluation exhibited that compounds 3, 5, 8—10 showed anti-inflammatory activity with the IC_(50) values in the range of 9.53—34.39 μmol/L, and compounds 3—7, and 9 showed notable α-glucosidase inhibitory activity (IC_(50): 6.02—257.11 μmol/L).展开更多
Main observation and conclusion Nineteen unprecedented 7-methoxylated caged xanthones(1—19)were isolated from the twigs of Garcinia oligantha under the guidance of NMR spectroscopy.Their structures and absolute confi...Main observation and conclusion Nineteen unprecedented 7-methoxylated caged xanthones(1—19)were isolated from the twigs of Garcinia oligantha under the guidance of NMR spectroscopy.Their structures and absolute configurations were demonstrated by extensive spectroscopic data,single-crystal X-ray diffraction,electronic circular dichroism(ECD)calculations,and the modified Mosher's method.Compound 1 is a rare scalemic 7-methoxylated neo-caged xanthone,which was resolved using HPLC with CD detection on a chiral-phase AD column,and compounds 2—3 are rare 7-methoxylated caged xanthones with the hydrogenatedΔ^(8(8a))double bond.Fourteen compounds exhibited promising inhibitory activities against four human cancer cell lines with IC50 values ranging from 1.9 to 14.3μmol/L.A cell apoptosis analysis using flow cytometry showed that compound 11 could induce apoptosis in a dose dependent manner.Moreover,PARP,caspase-9,and Bcl-2 western blotting suggested that compound 11-induced apoptosis may be involved in caspase-dependent pathway.展开更多
The present study was designed to investigate the chemical constituents of the roots of Cudrania fruticosa Wight. Compounds were isolated by various column chromatographic methods including silica gel, polyamide, seph...The present study was designed to investigate the chemical constituents of the roots of Cudrania fruticosa Wight. Compounds were isolated by various column chromatographic methods including silica gel, polyamide, sephadex LH-20, and semi-preparative HPLC. Their structures were elucidated by a combination of 1D and 2D NMR techniques, mass spectrometry, and chemical methods. Two new xanthones, Cudraxanthone T and U(1-2), along with four known compounds(3-6) were isolated from the roots of Cudrania fruticosa Wight.展开更多
Objective: To study the constituents from the whole plants of Gentianella acuta and their biological activities.Methods: The compounds were isolated by multiple chromatographic methods and the structures of mentione...Objective: To study the constituents from the whole plants of Gentianella acuta and their biological activities.Methods: The compounds were isolated by multiple chromatographic methods and the structures of mentioned isolates were determined by routine NMR experiments and chemical methods.Results: A phytochemical investigation to obtain intestine motility inhibitor resulted in the isolation of one new xanthone glycoside,gentixanthonoside A(1),along with nine tetrahydroxanthones,1,3,5R,8S-tetrahydroxy-5,6,7,8-tetrahydroxanthone(2),1,3,5S,8S-tetrahydroxy-5,6,7,8-tetrahydroxanthone(3),amarellin E(4),amarellin F(5),swertiachoside B(6),amarellin D(7),amarellin C(8),amarellin A(9),and amarellin B(10)from the whole plants of G.acuta.Conclusion: Compounds 2 –10 showed significant reduce effects on contraction tension at 40 μM.展开更多
Metabolism study has been carried out on 1-hydroxy-2,3,5-trimethoxyxanthone (HM-1) and 1-hydroxy-2,3,4,7- tetramethoxyxanthone (HM-2), which are two biologically active ingredients isolated from the Tibetan herb, ...Metabolism study has been carried out on 1-hydroxy-2,3,5-trimethoxyxanthone (HM-1) and 1-hydroxy-2,3,4,7- tetramethoxyxanthone (HM-2), which are two biologically active ingredients isolated from the Tibetan herb, Halenia elliptica D. Don., in rat liver microsomes in vitro. A method of high performance liquid chromatography coupled to ion trap time-of-flight mass spectrometry (LCMSn-ESI-IT-TOF) was applied to analyze metabolites of HM-1 and HM-2 on line, and five metabolites were identified containing 1,5-dihydroxy-2,3-dimethoxyxanthone (HM-5), 1,7-dihydroxy-2,3,4-trimethoxyxanthone (HM-9), 1,4, 7- trihydroxy-2,3-dimethoxyxanthone (HM-10), 1,4-dihydroxy-2,3,7-trimethoxyxanthone (HM-11) and 1,2-dilaydroxy-3,4,7- trimethoxyxanthone (HM-12). Among these metabolites, HM-9, HM-11, and HM-12 were isomers mutually. The results indicated that HM-1 and HM-2 occurred Phase I metabolic reaction of demethylation in rat microsomes in vitro.展开更多
An efficient synthetic method for multi-substituted xanthones was developed. The reaction of diaryliodonium salts and salicylates was employed for the preparation of the xanthones. This method proceeded through an int...An efficient synthetic method for multi-substituted xanthones was developed. The reaction of diaryliodonium salts and salicylates was employed for the preparation of the xanthones. This method proceeded through an intermolecular etherification-acylation to give target heterocycles in good yields(up to 91%). Multi-substituted xanthones were gained by shifting the substituent of salicylates or diaryliodonium salts展开更多
基金the National Natural Science Foundation of China (No. 30670215)
文摘Two novel xanthones, 1,6-dihydroxy-4,5-dimethoxyxanthone (1) and 1,5,6-trihydroxy-7,8-di(3-methyl-2-butenyl)-6',6'-dimethylpyrano(2',3':3,4)xanthone (2) were isolated from the bark of Garcinia xanthochymus by normal phase and reverse phase silica gel column chromatography. Their structures were elucidated by spectroscopic methods, especially 2D-NMR techniques.
基金Supported by Grants from the Center of Excellence for Innovation in Chemistry,Commission on Higher Education,No 48-03-3-00-144Faculty of Medicine,No 51-03-2-00-008 and Khon Kaen University,No 50-03-1-01-005,Research Funds,Khon Kaen University,Thailand
文摘AIM:To investigate the growth inhibitory mechanism of four caged xanthones from Garcinia hanburyi in cholangiocarcinoma(CCA) KKU-100 and KKU-M156 cells.METHODS:Four caged xanthones,selected on the basis of their anticancer potency and chemical structure diversities(i.e.isomorellin,isomorellinol,forbesione and gambogic acid) were used in this study.Growth inhibition of these caged xanthones was determined using the sulforhodamine B assay.Induction of apoptosis was assessed by observing cell morphology,ethidium bromide and acridine orange staining and DNA fragmentation assay.Levels of apoptotic-related gene and protein expressions were determined by a real-time reverse transcriptase polymerase chain reaction and Western blotting analysis,respectively.RESULTS:The compounds were found to inhibit growth of both cell lines in a dose-dependent manner and also showed selective cytotoxicity against the cancer cells when compared with normal peripheral blood mononuclear cells.Growth suppression by these compounds was due to apoptosis,as evidenced by the cell morphological changes,chromatin condensation,nuclear fragmentation,and DNA ladder formation.At the molecular level,these compounds induced down-regulation of Bcl-2 and survivin proteins with up-regulation of Bax and apoptosisinducing factor proteins,leading to the activation of caspase-9 and-3 and DNA fragmentation.The functional group variations did not appear to affect the anticancer activity with regard to the two CCA cell lines;however,at a mechanistic level,isomorellinol exhibited the highest potency in increasing the Bax/Bcl-2 protein expression ratio(120 and 41.4 for KKU-100 and KKU-M156,respectively) and in decreasing survivin protein expression(0.01 fold as compared to control cells in both cell lines).Other activities at the molecular level indicate that functional groups on the prenyl side chain may be important.CONCLUSION:Our findings for the first time demonstrate that four caged xanthones induce apoptosis in CCA cells which is mediated through a mitochondriadependent signaling pathway.
基金The authors would like to acknowledge Agilent Technologies for providing the capillary electrophoresis system and Bioanalytical System for present of sulfated b-CD. The study is supported by NSFC Grant No. 29875001.
文摘A capillary electrophoresis (CE) method has been firstly used for the separation of the therapeutically important xanthones from Securidaca inappendiculata. The separation of the nine xanthones was systematically optimized with respect to pH, concentration of running buffers, addition of sulfated b-CD, applied voltage and column temperature. Baseline separation was achieved for the nine xanthones in less than 15 minutes using a background electrolyte consisting of 200 mmol/L borate (pH 9.5) and 10 mmol/L sulfated b-CD.
文摘A microemulsion electrokinetic chromatography method has been firstly used for the separation of the therapeutically important xanthones from Securidaca inappendiculata. The separation of the nine xanthones was systematically optimized with respect to pH, composition of microemulsion, addition of cyclodextrins, applied voltage and column temperature. Baseline separation was successfully achieved for the nine xanthones, which was also compared with that by micellar electrokinetic chromatography.
文摘Introduction Xanthones are secondary metabolites commonly occurring in a few higher plant families, fungi and lichen. Their high taxonomic value in such families and their pharmacological properties, including in vitro cytotoxicity, in vivo antitumour activity, antifungal, antibacterial, antiinflammatory properties and aldose reductase inhibitory activity have provoked great interest. The discovery of the antidiabetic activity of some axnthones' from Swertiaceae has prompted us to undertake a more broadly search for novel xanthones from plants of Polygalaceae. The phytochemical investigation has not been performed on this plant up to now. Herein we report the isolation and structure elucidation of two new xanthones ( compounds 1 and 2 ) and three known xanthones (compound 3, 4 and 5 ).
文摘The thermodynamic properties of dibenzofurans (DFs), xanthones (XTs) and an-thraquinones (AQs) with one and two positions substituted with hydroxyls in the ideal gas state at 298.15 K and 1.013×10^5 pa were calculated at the B3LYP/6-311G^* level using Gaussian 03 program. The isodesmic reactions were designed to calculate the standard free energy of formation (△fG^θ). Three types of hydrogen bonds exist in the three kinds of chemicals and their bond energies were ascertained as 7-15, 15-23 and 49-58 kJ·mo1^-1 respectively by comparing the △fG^θ values. Electronic density topology analysis was applied to validate the strength of bond.
基金We thank the fourth national survey of traditional Chinese medicine resources(2018016)for funding this research.
文摘Thirteen xanthones were isolated from L.rotatum,which were established as l,8-dihydroxy-3,4,5-trimethoxyxanthone(1);l-hydroxy-3异,8-trimethoxyxanthone(2);8-hydroxy-l,3?5-trimethoxyxaiithone(3);l-hydroxy-3,4,5-trimethoxyxanthone(4);l-hydroxy-3,5,8-trimethoxyxanthone(5);l,4,8-trihydroxy-5,6-dimethoxyxanthone(6);l,3,8-trihydroxy-4,7-dimethoxyxanthone(;7)l,8-dihydroxy-3,7-dimethoxyxanthone(8);l-hydroxy-3,5-dimethoxyxanthone(9);l-hydroxy-2,3,4,5-tetramethoxyxanthone(;10)l-hydroxy-2,3,4,7-tetramethoxyxanthone(11);l,7-dihydroxy-3,8-dimethoxyxanthone(12);rel-l,3,5,8-tetrahydroxy-2,4,6,7-tetrahydroxanthen-9-one(13).Compounds 4,6,7,9,10,11,12 and 13 are reported for the first time from Lomatogonium.Furthermore,the activity of xanthones was assessed.
基金The project was supported by the Key Laboratory for Natural Medicine of Gansu Province and Foundation of Lanzhou University of Technology
文摘In order to study the relationship between biological and pharmacological activities with their structures, a series of tri- and tetra-oxygenated xanthones including 1-hydroxyl-2,3,4,7- tetramethoxy xanthone 1, 1-hydroxyl-2,3,4,5-tetramethoxyl xanthone 2, 1-hydroxyl-3,5-dimethoxy- xanthone 3, 1,8-dihydroxyl-3,5-dimethoxyl xanthone 4 and 1,5,8-trihydroxyl-3-methoxy xanthone 5 have been isolated from Swertia chirayita. Their structures were established on the basis of spectral and chemical evidences. The crystal structure of 5 was also investigated by single-crystal X-ray diffraction analysis. It crystallizes in the triclinic system, space group P?with a = 7.1540(10), b = 7.520(2), c = 10.671(2) , V = 562.7(2) 3 , α = 86.50(3), β = 80.06(3) , γ = 85.00(3), Z = 2, Dc = 1.618 g/m3, R = 0.0405, wR = 0.1028 and F(000) = 284. The molecular structure of 5 is nearly planar and four substituents are much closer to the plane. Compound 5 contains three intermolecular hydro- gen bonds. A recent study shows that phenolic hydroxyls in xanthones are the main active groups capable of scavenging OH and O2.
基金Supported by the NNSFC (20737001, 20977046)NSF of Zhejiang Province (2008Y507280)
文摘The thermodynamic properties of xanthone(XTH) and 135 polybrominated xanthones(PBXTHs) in the standard state have been calculated at the B3LYP/6-31G* level using Gaussian 03 program.The isodesmic reactions were designed to calculate the standard enthalpy of formation(△fHθ) and standard free energy of formation(△fGθ) of PBXTH congeners.The relations of these thermodynamic parameters with the number and position of Br atom substitution(NPBS) were discussed,and it was found that there exist high correlation between thermodynamic parameters(entropy(Sθ),△fHθ and △fGθ) and NPBS.According to the relative magnitude of their △fGθ,the relative stability order of PBXTH congeners was theoretically proposed.The relative rate constants of formation reactions of PBXTH congeners were calculated,Moreover,the values of molar heat capacity at constant pressure(Cp,m) from 200 to 1000 K for PBXTH congeners were also calculated,and the temperature dependence relation of them was obtained,suggesting very good relationships between Cp,m and temperature(T,T^1 and T^2) for almost all PBXTH congeners.
基金the Fundacao de Amparo a Pesquisa do Estado de Sao Paulo(FAPESP),for fundingthe Conselho Nacional de Desenvolvimento Científico e Tecnologico(CNPq),for grants to L.C.Santos.
文摘The linearity, stability, accuracy and inter-day precisions of the assay method were evaluated in methanolic aerial-part extracts of Paepalanthus giganteus and Syngontnhus nitens from the Eriocaulaceae family. Their small capitulae hinder morphological analysis, and thus complicate taxonomic studies of these species, which present anti-ulcer, antimutagenic and antioxidant activities. Taxonomic studies of these plants revealed that the Paepalanthus genus presents flavonols and naphthopyranones while the Syngontnhus genus has flavone and xanthone as majority compounds. The prepared samples were analyzed quantitatively by High Performance Liquid Chromatography with PDA detection for the presence of quercetin, luteolin, 3,6-dimethoxy-1,5,7-tri-hydroxyxanthone and paepalantine. The substances were recovered from these samples at rates from 98.01 to 99.99%. The coefficient of variation in the quantitative analysis of the sample com- pounds was under 5%. The linearity of the method was determined by linear regression. The analysis of the samples spiked with known amounts of analyte demonstrated that the response was proportional to the concentrations of the sam- ples with re-spective determination coefficients of r2 = 0.9999 (luteolin and 3,6-dimethoxy-1,5,7-tri-hydroxyxanthone) and r2 = 0.9998 (quercetin and paepalantine) for the linear range of the analytical calibration curves of the samples. The detection limits were 0.07 μg?mL–1 for quercetin and luteolin, 0.06 μg?mL–1 for 3,6-dimethoxy-1,5,7-tri-hydroxyxanthone and 0.10 μg?mL–1 for paepalantine. The quantification limits were 0.23 μg?mL–1 for quercetin and luteolin, 0.20 μg?mL–1 for 3,6-dimethoxy-1,5,7-tri-hydroxyxanthone and 0.33 μg?mL–1 for paepalantine by LC. The method was considered sen- sitive for quantification of the quercetin, luteolin, 3,6-dimethoxy-1,5,7-tri-hydroxyxanthone and paepalantine in plant samples.
基金supported by the National Natural Science Foundation of China(No.81360673)
文摘AIM: To study the chemical constituents of Lomatogonium carinthiacum(Wulfen) Rchb. METHOD: The CHCl3-soluble fraction was separated by chromatography and the structures of the new compounds were elucidated by spectral experiments. RESULTS: Two new xanthones, 1, 8-dihydroxy-4, 5-dimethoxy-6, 7-methylenedioxyxanthone(1), 1, 4, 8-trimethoxyxanthone-6-O-β-D-glucoronyl-(1→6)O-β-D-glucoside(2) were isolated from the whole plant of Lomatogonium carinthiacum. CONCLUSION: Compounds 1 and 2 are new natural products.
基金supported by the National Natural Science Foundation of China(32170406)the“Double First-Class”University project(CPU2018GY08).
文摘Elodexanthones A—J (1—10), two pairs of rearranged isoprenylated xanthone enantiomers with an unprecedent 6/6/5/6 tetracyclic core (1—2) along with seven new isoprenylated xanthones (3—9) and a pair of phenylpropanoid xanthones (10), were purified and enantio-separated from the whole plant of Hypericum elodeoides. Their structures including absolute configurations were characterized by the comprehensive analysis of NMR, HRESIMS, NMR calculations, and ECD calculations. Through Bayer-Villiger oxidation, Claisen condensation and electrophilic addition, the rearranged skeletons of elodexanthones A—B (1—2) were generated from isoprenylated xanthone precursors. The bioactivities evaluation exhibited that compounds 3, 5, 8—10 showed anti-inflammatory activity with the IC_(50) values in the range of 9.53—34.39 μmol/L, and compounds 3—7, and 9 showed notable α-glucosidase inhibitory activity (IC_(50): 6.02—257.11 μmol/L).
基金sponsored partly by grants from the Three-year Development Plan Project for Traditional Chinese Medicine(No.ZY(2018-2020)-CCCX-2001-02)the Shanghai Sailing Program(No.17YF1419500)and NSFC(No.81803545)+2 种基金We are also grateful to NSFC-Joint Foundation of Yunnan Province(No.U1902213)the Key-Area ResearchDevelopment Program of Guangdong Province(No.2020B1111110003)for financial support.
文摘Main observation and conclusion Nineteen unprecedented 7-methoxylated caged xanthones(1—19)were isolated from the twigs of Garcinia oligantha under the guidance of NMR spectroscopy.Their structures and absolute configurations were demonstrated by extensive spectroscopic data,single-crystal X-ray diffraction,electronic circular dichroism(ECD)calculations,and the modified Mosher's method.Compound 1 is a rare scalemic 7-methoxylated neo-caged xanthone,which was resolved using HPLC with CD detection on a chiral-phase AD column,and compounds 2—3 are rare 7-methoxylated caged xanthones with the hydrogenatedΔ^(8(8a))double bond.Fourteen compounds exhibited promising inhibitory activities against four human cancer cell lines with IC50 values ranging from 1.9 to 14.3μmol/L.A cell apoptosis analysis using flow cytometry showed that compound 11 could induce apoptosis in a dose dependent manner.Moreover,PARP,caspase-9,and Bcl-2 western blotting suggested that compound 11-induced apoptosis may be involved in caspase-dependent pathway.
基金supported by the National Natural Science Foundation of China(No.81172949)the Program for Excellent Talents of Liaoning Province of China(No.LR2013058)
文摘The present study was designed to investigate the chemical constituents of the roots of Cudrania fruticosa Wight. Compounds were isolated by various column chromatographic methods including silica gel, polyamide, sephadex LH-20, and semi-preparative HPLC. Their structures were elucidated by a combination of 1D and 2D NMR techniques, mass spectrometry, and chemical methods. Two new xanthones, Cudraxanthone T and U(1-2), along with four known compounds(3-6) were isolated from the roots of Cudrania fruticosa Wight.
基金supported by National Natural Science Foundation of China (81673688)
文摘Objective: To study the constituents from the whole plants of Gentianella acuta and their biological activities.Methods: The compounds were isolated by multiple chromatographic methods and the structures of mentioned isolates were determined by routine NMR experiments and chemical methods.Results: A phytochemical investigation to obtain intestine motility inhibitor resulted in the isolation of one new xanthone glycoside,gentixanthonoside A(1),along with nine tetrahydroxanthones,1,3,5R,8S-tetrahydroxy-5,6,7,8-tetrahydroxanthone(2),1,3,5S,8S-tetrahydroxy-5,6,7,8-tetrahydroxanthone(3),amarellin E(4),amarellin F(5),swertiachoside B(6),amarellin D(7),amarellin C(8),amarellin A(9),and amarellin B(10)from the whole plants of G.acuta.Conclusion: Compounds 2 –10 showed significant reduce effects on contraction tension at 40 μM.
基金the supports of the National Natural Science Foundation of China(No.30873115)National Science and Technology Special Projects(Nos.2009zx09301-003-5-1 and 2009zx09301-003-7-1)supported by the analytical center of the Peking branch of Japanese Shimadzu Corporation to provide the LCMS~n-IT-TOF system
文摘Metabolism study has been carried out on 1-hydroxy-2,3,5-trimethoxyxanthone (HM-1) and 1-hydroxy-2,3,4,7- tetramethoxyxanthone (HM-2), which are two biologically active ingredients isolated from the Tibetan herb, Halenia elliptica D. Don., in rat liver microsomes in vitro. A method of high performance liquid chromatography coupled to ion trap time-of-flight mass spectrometry (LCMSn-ESI-IT-TOF) was applied to analyze metabolites of HM-1 and HM-2 on line, and five metabolites were identified containing 1,5-dihydroxy-2,3-dimethoxyxanthone (HM-5), 1,7-dihydroxy-2,3,4-trimethoxyxanthone (HM-9), 1,4, 7- trihydroxy-2,3-dimethoxyxanthone (HM-10), 1,4-dihydroxy-2,3,7-trimethoxyxanthone (HM-11) and 1,2-dilaydroxy-3,4,7- trimethoxyxanthone (HM-12). Among these metabolites, HM-9, HM-11, and HM-12 were isomers mutually. The results indicated that HM-1 and HM-2 occurred Phase I metabolic reaction of demethylation in rat microsomes in vitro.
基金supported by the National Natural Science Foundation of China (Nos. 21372138 and 21672120)The National Key Research and Development Program of China (No. 2016YFB0401400)+1 种基金the Fok Ying Tong Education Foundation of China (No. 151014)the Postdoctoral Foundation of the PekingTsinghua Joint Center for Life Sciences
文摘An efficient synthetic method for multi-substituted xanthones was developed. The reaction of diaryliodonium salts and salicylates was employed for the preparation of the xanthones. This method proceeded through an intermolecular etherification-acylation to give target heterocycles in good yields(up to 91%). Multi-substituted xanthones were gained by shifting the substituent of salicylates or diaryliodonium salts