Two new xanthone derivatives from the algicolous marine fungus Wardomyces anomalus

A marine fungal isolate, identified as Wardomyces anomalus, was cultivated and found to produce two new xanthone derivatives, 2,3,6,8-tetrahydroxy-1-methylxanthone (1) and 2,3,4,6,8-pentahydroxy-1-methylxanthone (2), in addition to the known xanthone derivative 3,6,8-trihydroxy-1-methylxanthone (3) and the known fungal metabolite 5-(hydroxymethyl)-2-furanocarboxylic acid (4). The structures of all compounds were determined on the basis of extensive spectroscopic measurements (1D and 2D NMR, MS, UV, and IR). Compounds 1 and 4 showed significant antioxidant activities. The total extract and 1, 3, and 4 were shown to be inhibitors of p56(lck)tyrosine kinase.     

New secondary metabolites from the marine endophytic fungus Apiospora montagnei

The marine fungus Apiospora montagnei was isolated from the inner tissue of the North Sea alga Polysiphonia violacea. Cultivation of this fungal strain led to the isolation of several new secondary metabolites, including the diterpene myrocin A (1) and the polyketide apiosporic acid (2). Furthermore the new monomethyl ester of 9-hydroxyhexylitaconic acid (3) and the (-)-enantiomer (4) of the known (+)-hexylitaconic acid were found together with the known (+)-epiepoxydon (5), (+)-epoxydon monoacetate, R-mellein, R-8-methoxymellein, 5-hydroxymethylfuran-2-carboxylic acid, and the xanthone derivative anomalin A. The structures were elucidated mainly by 1D and 2D NMR, MS, UV, and IR spectral data. Compound 5 exhibited significant cytoxicity against human cancer cell lines.     

卵叶远志地上部分酮类成分研究

目的:系统研究卵叶远志Polygala sibirica地上部分的化学成分.方法:采用各种柱色谱方法进行分离,利用波谱数据鉴定化合物的结构.结果:分离、鉴定了10个化合物,其中6个为(口山)酮类化合物,分别为6-羟基-1,2,3,7-四甲氧基(口山)酮(1);1,2,3,6,7-五甲氧基(口山)酮(2);1,7-二羟基-2,3-亚甲二氧基(口山)酮(3);1,7-二羟基-2,3-二甲氧基(口山)酮(4);1,3,7-三羟基-2-甲氧基(口山)酮(5);1,6,7-三羟基-2,3-二甲氧基(口山)酮(6).此外还分离得到α-菠甾醇(7);α-菠甾醇-3-O-β-D-葡萄糖苷(8);角鲨烯(9)和远志糖醇(10).结论:化合物1～10均为首次从本植物中分离得到.     

A New Prenylated Xanthone from Root Barks of Cudrania cochinchinensis

Objective To study the chemical constituents from the root barks of Cudrania cochinchinensis. Methods The chemical constituents were isolated and purified by silica gel column chromatography. The structures of the compounds were identified on the basis of spectral data(MS,1H-NMR,13C-NMR, and 2D NMR) and by the comparison of spectroscopic data with the reported values in the literatures. Results A new xanthone, 1,6,7-trihydroxy-4-(1,1-dimethylallyl)-3-methoxyxanthone(1) and a known prenylated xanthone 1,5,6-trihydroxy-4-(1,1-dimethylallyl)-3-methoxyxanthone(isocudraniaxanthone B, 2) were isolated from the root barks of C. cochinchinensis. Conclusion Compound 1 is a new prenylated xanthone. Isomers 1 and 2 are obtained from this plant for the first time.     

Chemical constituents from Drypetes littoralis.

Chemical investigation of Drypetes littoralis yielded three new tricyclic diterpenes, drypetenones A, B, and C (1--3), and one new xanthone (4). Spectral analyses and chemical correlations established the structures as 10S-12-hydroxy-11-methoxy-13-methylpodocarpa-1,5,8,11,13-pentaene-3,7-dione, (1), 10S-12-hydroxy-11-methoxy-13-methylpodocarpa-5,8,11,13-tetraene-3,7-dione (2), 10S-12-hydroxy-6,11-dimethoxy-13-methylpodocarpa-1,5,8,11,13-pentaene-3,7-dione (3), and 1-hydroxy-7-hydroxymethyl-6-methoxyxanthone (4). Complete (13)C NMR assignment of boehmenan D (5) is also made.     

苏木的化学成分研究

目的研究苏木Caesalpinia sappan的化学成分。方法采用硅胶、葡聚糖凝胶Sephadex LH-20柱色谱、半制备液相色谱等方法分离纯化,通过理化性质、波谱数据及与对照品共薄层色谱鉴定化合物结构。结果从苏木心材95%乙醇提取物的石油醚萃取部位分离并鉴定了11个化合物,分别为1-羟基-7-甲氧基呫吨酮(1)、2-羟基呫吨酮(2)、1,5-二羟基呫吨酮(3)、1,7-二羟基呫吨酮(4)、大黄酚(5)、木栓酮(6)、熊果酸(7)、β-谷甾醇棕榈酸酯(8)、麦角甾烷-4,6,8(14),22(23)-四烯-3-酮(9)、豆甾醇(10)、β-谷甾醇(11)。结论除化合物10、11外,其余均为首次从该植物中分离得到,其中化合物1～5为首次从云实属植物中分离得到,同时也是该属植物中首次分得的呫吨酮和蒽醌类化合物。     

Norlignans, acylphloroglucinols, and a dimeric xanthone from Hypericum chinense

Two new norlignans, hyperiones A (1) and B (2), three new acylphloroglucinols, aspidinol C (3) and hyperaspidinols A (5) and B (6), the known compound aspidinol D (4), and the symmetrical dimeric xanthone hyperidixanthone (7) were isolated from Hypericum chinense. Their structures were established by spectroscopic analysis. In an antibacterial assay using a panel of multidrug-resistant (MDR) strains, compounds 3 and 4 exhibited promising activity against the NorA efflux protein overexpressing MDR Staphylococcus aureus strain SA-1199B with a minimum inhibitory concentration (MIC) of 2 μg/mL (8.4 μM) and 4 μg/mL (16.8 μM), respectively. The positive control antibiotic norfloxacin showed activity at MIC 32 μg/mL (100 μM).     

Antimicrobial Assessment of Resins from Calophyllum Antillanum and Calophyllum Inophyllum

The Calophyllum genus is well‐known for its antimicrobial and cytotoxic activities, and therefore, we analyzed these biological activities for resins of Calophyllum antillanum and Calophyllum inophyllum growing in Cuba. C. antillanum resins showed a potent activity against Plasmodium falciparum (IC₅₀ = 0.3 ± 0.1 µg/mL), while its cytotoxicity against MRC‐5 cells was much lower (IC₅₀ = 21.6 ± 1.1 µg/mL). In contrary, the resin of C. inophyllum showed an unspecific activity. The presence of apetalic acid, isoapetalic acid, calolongic acid, pinetoric acid I, pinetoric acid II, isocalolongic acid, pinetoric acid III, and isopinetoric acid III in C. antillanum resins was also confirmed. These results demonstrated for the first time the potential activity of C. antillanum resins against P. falciparum. Copyright © 2015 John Wiley & Sons, Ltd.     

观赏獐牙菜中新(左)口(右)山酮的化学研究

 目的研究我国民族药观赏獐牙菜(Swertia decora Franch)的化学成分。方法用常规的硅胶柱层析和薄层色谱法进行分离,根据化合物的理化性质及一维、二维波谱解析鉴定其结构。结果从观赏獐牙菜脂溶性部分得到6个化合物,分别鉴定为1-羟基-4,5,6,7-四甲氧基酮(swertiadecoraxanthoneⅠ)(Ⅰ);1,3,8-三羟基-2,5-二甲氧基(左)口(右)山酮(Ⅱ);1,8-二羟基-3,7-二甲氧基(左)口(右)山酮(methylswertianin,Ⅲ);1-羟基-3,7,8-三氧甲基(左)口(右)山酮(decussatin,Ⅳ);1,7,8-三羟基-3-甲氧基(左)口(右)山酮(swertianin,Ⅴ)及二十四烷酸(tetracosanoic acid Ⅵ)。结论 化合物Ⅱ为新化合物,定名为观赏獐牙菜(左)口(右)山酮 Ⅱ(swertiadecoraxanthoneⅡ),其他均为首次从该植物中分离到。     

心叶淫羊藿的化学成分研究

目的对心叶淫羊藿的化学成分进行研究。方法采用硅胶柱层析及重结晶、SephadexLH-20等技术分离、纯化化合物,应用波谱方法鉴定结构。结果共分离鉴定13个化合物,它们的结构确定为黄酮苷类7个:淫羊藿苷(Icariin),淫羊藿苷Ⅰ(IcarisideⅠ),淫羊藿苷Ⅱ(IcarisideⅡ),淫羊藿定A(EpimedinA),淫羊藿定B(EpimedinB),淫羊藿定C(EpimedinC),Icaritin-3-O-D-rhamnoside;(口山)酮类(Xanthone)2个:1,3,5,8-四羟基(口山)酮,1-羟基-3,4,5,-三甲氧基(口山)酮;其他醇类4个:对甲氧基苯酚(p-methoxyphenol),二十三烷酸(behenicacid),β-谷甾醇(β—Sitosterol),胡萝卜苷(daucosterol)。结论化合物Ⅳ、Ⅴ、Ⅶ、Ⅷ、Ⅸ、Ⅹ、Ⅺ为首次从心叶淫羊藿中分离得到。     

Xanthone glycosides from Polygala tenuifolia and their conformational analyses

Seven xanthone glycosides were isolated from the cortexes of Polygala tenuifolia, and their structures were identified as polygalaxanthones VIII-XI (1-4), sibiricoxanthone B (5), 7-O-methylmangiferin (6), and lancerin (7), on the basis of spectroscopic analyses. Compounds 1-4 are new xanthone glycosides, and compounds 4 and 5 exist as rotamers. To explain this phenomenon, conformational analyses were performed on compounds 4 and 5 and other compounds with similar skeletons that were isolated from P. tenuifolia.     

Sucrose esters and xanthone C-glycosides from the roots of Polygala sibirica.

Six new sucrose esters, sibiricoses A(1)-A(6) (1-6), two new xanthone C-glycosides, sibiricaxanthones A (7) and B (8), and a new acetophenone glycoside, sibiricaphenone (9), were isolated from the roots of Polygala sibirica together with six known glycosides. The structures of new compounds were elucidated on the basis of chemical and spectroscopic evidence. The structure of the known xanthone glycoside, polygalaxanthone III (10), was revised.     

Tetrasaccharide multi-esters and xanthone glycosides from the roots of Polygala wattersii

Ten new tetrasaccharide multi-esters, watteroses A-J (1-10), and two new xanthone glycosides, wattersiixanthones A (11) and B (12), were isolated from the roots of Polygala wattersii, together with 11 known compounds (10 oligosaccharide multi-esters and a xanthone glycoside). The structures of new compounds were elucidated on the basis of chemical and spectroscopic evidence.     

New cytotoxic lupane triterpenoids from the twigs of Coussarea paniculata

Bioassay-guided fractionation of a CH(2)Cl(2)-MeOH extract of the twigs of Coussarea paniculata using a yeast-based assay for potential DNA-damaging agents resulted in the isolation of three new lupane triterpenoids, 1-3, in addition to eight known triterpenoids, lupeol (4), lupeyl acetate (5), betulin (6), betulinic acid (7), 3-epi-betulinic acid (8), 3-epi-betulinaldehyde (9), oleanolic acid (10), and ursolic acid (11). The structures of the new compounds were established as lup-20(29)-en-3beta,25-diol (1), lup-20(29)-en-11alpha-ol-25,3beta-lactone (2), and 3-deoxybetulonic acid (3), on the basis of extensive 1D and 2D NMR spectroscopic data interpretation and chemical conversion.     

A new ursane triterpene from Monochaetum vulcanicum that inhibits DNA polymerase beta lyase

Bioassay-directed fractionation of a butanone extract of Monochaetum vulcanicum resulted in the isolation of a new triterpene (1) and four known compounds, ursolic acid (2), 2alpha-hydroxyursolic acid (3), 3-(p-coumaroyl)ursolic acid (4), and beta-sitosteryl-beta-d-galactoside (5). The structure of the new compound 1 was established as 3beta-acetoxy-2alpha-hydroxyurs-12-en-28-oic acid on the basis of extensive 1D and 2D NMR spectroscopic interpretation and chemical derivatization. Compounds 1-3 and 5 exhibited polymerase beta lyase activity.     

Xanthones and benzophenones from the stems of Garcinia multiflora

Two new xanthone derivatives, garcinianones A (1) and B (2), two new benzophenone derivatives, 4,6,4'-trihydroxy-2,3'-dimethoxy-3-prenylbenzophenone (3) and 4,6,3',4'-tetrahydroxy-2-methoxybenzophenone (4), and a new inseparable mixture of (1E,22Z)-1,22-diferuloyloxydocosane and (1E,24Z)-1,24-diferuloyloxyteracosane (5), together with the previously known 3,8-dihydroxy-2,4,6-trimethoxyxanthone, 6,3'-dihydroxy-2,4-dimethoxybenzophenone, maclurin (6), 2,4,6,3'-tetrahydroxybenzophenone (7), and naringenin, were isolated from the stems of Garcinia multiflora. The structures of 1-5 were elucidated by extensive analysis of their spectral data. Compounds were evaluated in the brine shrimp lethality test and in the DPPH antioxidant assay.     

Microbial O-demethylation, hydroxylation, sulfation, and ribosylation of a xanthone derivative from Halenia elliptica

1-Hydroxy-2,3,5-trimethoxyxanthone (1), one of the major xanthone derivatives isolated from Halenia elliptica, was biotransformed by two fungi, Trichothecium roseum and Paecilomyces marquandii. Transformation of 1 by T. roseumgave 1,5-dihydroxy-2,3-dimethoxyxanthone (2), 5-O-sulfate-1-hydroxy-2,3-dimethoxyxanthone (3), 5-O-sulfate-1-hydroxy-2,3,7-trimethoxyxanthone (4), 5-O-beta-ribofuranosyl-1-hydroxy-2,3-dimethoxyxanthone (5), and 1,5,6-trihydroxy-2,3-dimethoxyxanthone (6). Compound 2 was also formed by P. marquandii. The structures of the isolated compounds were elucidated by spectroscopic analyses. Among the five microbial-converted compounds, 3, 4, 5, and 6 are new compounds.     

Xanthones from Gentianella amarella ssp. acuta with acetylcholinesterase and monoamine oxidase inhibitory activities

Two new xanthone glycosides, corymbiferin 3-O-beta-D-glucopyranoside (1) and swertiabisxanthone-I 8'-O-beta- d-glucopyranoside (2), were isolated from Gentianella amarella ssp. acuta, along with eight known xanthones: triptexanthoside C, veratriloside, corymbiferin 1-O-glucoside, swertianolin, norswertianolin, swertiabisxanthone-I, bellidin, and bellidifolin, four of them identified for the first time in G. amarella ssp. acuta. The isolation was conducted mainly by centrifugal partition chromatography, and the structures of the isolated compounds were established on the basis of spectrometric data including 2D NMR and mass spectrometry. Xanthones were weakly active against acetylcholinesterase (AChE), except triptexanthoside C, which inhibited AChE with an IC(50) of 13.8 +/- 1.6 microM. Some compounds were active against monoamine oxidases (MAO): bellidin and bellidifolin showed interesting inhibitory activity of MAO A, while swertianolin, the 8-O-glucopyranoside form of bellidifolin, gave 93.6% inhibition of MAO B activity at 10(-5) M.     

Cytotoxic and NF-κB inhibitory constituents of the stems of Cratoxylum cochinchinense and their semisynthetic analogues

A new caged xanthone (1), a new prenylxanthone (2), seven known xanthones, and a known sterol glucoside were isolated from the stems of Cratoxylum cochinchinense, collected in Vietnam. Compounds 1 and 2 were determined structurally by analysis of their spectroscopic data. In addition, five new (10 and 16-19) and eight known prenylated xanthone derivatives were synthesized from the known compounds α-mangostin (3) and cochinchinone A (6). Several of these substances were found to be cytotoxic toward HT-29 human colon cancer cells, with the most potent being 3,6-di-O-acetyl-α-mangostin (8, ED50, 1.0 μM), which was tested further in an in vivo hollow fiber assay, but found to be inactive at the highest dose used (20 mg/kg; ip). Of the substances evaluated in a NF-κB p65 inhibition assay, 1,3,7-trihydroxy-2,4-diisoprenylxanthone (5) exhibited the most potent activity (IC50, 2.9 μM). In a mitochondrial transmembrane potential assay, two new compounds, 1 (IC50, 3.3 μM) and 10 (IC50, 1.4 μM), and two known compounds, 3 (α-mangostin, IC50, 0.2 μM) and 11 (3,6-di-O-methyl-α-mangostin, IC50, 0.9 μM), were active. A preliminary analogue development study showed that 3,6-diacetylation and 6-benzoylation both slightly increased the cytotoxicity of α-mangostin (3), whereas methylation reduced such activity. In contrast, neither acetylation, benzoylation, nor methylation enhanced the cytotoxicity of cochinchinone A (6).     

Oleanane-type triterpenes from the flowers and roots of Saussurea muliensis

Six new oleanane-type triterpenes (1- 6), along with five known compounds, were isolated from the flowers and roots of Saussurea muliensis. On the basis of spectroscopic methods, with special emphasis on 1D and 2D NMR techniques, the structures of the new compounds were characterized as 3beta,22alpha-dihydroxyolean-12-en-30-oic acid (1), 3alpha-(E)-caffeoyloxyolean-12-en-30-oic acid (2), 3alpha-(E)-coumaroyloxyolean-12-en-30-oic acid (3), 3alpha,22alpha-diacetoxy-20beta,21alpha,29-trihydroxy-30-norolean-12-ene (4), 3alpha,22alpha-diacetoxy-21alpha,29-dihydroxy-20beta-methoxy-30-norolean-12-ene (5), and 3alpha,22alpha-diacetoxy-20beta,21alpha-dihydroxy-29-palmityloxy-30-norolean-12-ene (6). The isolated compounds (1- 6) were not active against Staphylococcus aureus, Escherichia coli, Bacillus cereus, and Candida albicans.