Showing papers on "Xanthone published in 2003"
TL;DR: The results obtained in the present study confirm that peels originating from mango fruit processing are a promising source of phenolic compounds that might be recovered and used as natural antioxidants or functional food ingredients.
Abstract: Flavonol O- and xanthone C-glycosides were extracted from mango (Mangifera indica L. cv. "Tommy Atkins") peels and characterized by high-performance liquid chromatography-electrospray ionization mass spectrometry. Among the fourteen compounds analyzed, seven quercetin O-glycosides, one kaempferol O-glycoside, and four xanthone C-glycosides were found. On the basis of their fragmentation pattern, the latter were identified as mangiferin and isomangiferin and their respective galloyl derivatives. A flavonol hexoside with m/z 477 was tentatively identified as a rhamnetin glycoside, which to the best of our knowledge, has not yet been reported in mango peels. The results obtained in the present study confirm that peels originating from mango fruit processing are a promising source of phenolic compounds that might be recovered and used as natural antioxidants or functional food ingredients.
228 citations
TL;DR: A marine fungal isolate, identified as Wardomyces anomalus, was cultivated and found to produce two new xanthone derivatives that showed significant antioxidant activities and were shown to be inhibitors of p56(lck)tyrosine kinase.
Abstract: 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 p56lck tyrosine kinase.
104 citations
TL;DR: A new compound, IB-00208, has been isolated from the fermentation broth of an actinomycete isolated from a marine environment and shows cytotoxic activity on tumor cell lines and bactericidal activity against gram-positive bacteria.
Abstract: A new compound, IB-00208, has been isolated from the fermentation broth of an actinomycete isolated from a marine environment. The strain was identified as Actinomadura sp. by its chemical and phylogenetic characteristics. The compound shows cytotoxic activity on tumor cell lines and bactericidal activity against Gram-positive bacteria.
62 citations
TL;DR: Repeated column chromatography of the n-BuOH fraction of the 70% EtOH of the dried leaves of Bombax malabaricum led to the isolation of mangiferin, a xanthone, found to be identical to shamimin.
Abstract: Repeated column chromatography of the n-BuOH fraction of the 70% EtOH of the dried leaves of Bombax malabaricum led to the isolation of mangiferin, a xanthone. Mangiferin was identified by UV,'H- and 13 C-NMR spectroscopy and electrospray mass spectrometry. It was found to be identical to shamimin, a compound for which originally a flavonol structure was proposed, and the structure of which has to be revised.
47 citations
41 citations
TL;DR: Three prenylated xanthones isolated from the wood of Garcinia xanthochymus showed a markedly enchancing activity of nerve growth factor (NGF)-mediated neurite outgrowth on PC12D cells.
33 citations
TL;DR: The present results suggest that xanthone preserves endothelial cells and inhibits the increased adhesion of monocytes to endothelial Cells induced by ox-LDL, and that the protective effect of xanth one (1,3,5,6-tetrahydroxyxanthone) on endothelium cells is related to reduction of ADMA concentration via increase of DDAH activity.
32 citations
TL;DR: Condensation of a benzopyranonphthalide with Michael acceptors provides an efficient, general method for regiospecific preparation of xanthones as well as linear and angular polycyclic aromatic systems containing a xanthone fragment.
32 citations
TL;DR: In this paper, a total synthesis of atroviridin (1 ) based on biosynthetic principles is presented. But the synthesis of the natural product was constructed by coupling aryl bromide 8 with aldehyde 7 and subsequent intramolecular conjugate addition on a quinone precursor.
28 citations
TL;DR: A new prenylated xanthone, 1,3,5,6-tetrahydroxy-4,7,8-tri(3-methyl-2-butenyl)xanthone was isolated from the wood of Garcinia xanthochymus and elicited marked enhancement of nerve growth factor-mediated neurite outgrowth in PC12D cells.
Abstract: A new prenylated xanthone, 1,3,5,6-tetrahydroxy-4,7,8-tri(3-methyl-2-butenyl)xanthone (1), was isolated from the wood of Garcinia xanthochymus together with a known xanthone, garciniaxanthone E (2). Their structures were determined by spectroscopic analysis. Compounds 1 (3 microM) and 2 (10 microM) elicited marked enhancement of nerve growth factor-mediated neurite outgrowth in PC12D cells.
27 citations
TL;DR: A new xanthone (2), 3-(2-hydroxyethoxy)xanthone, and three known compounds, 1-Hydroxyxanth one, salicylic acid and the sesquiterpene oplopanone were isolated for the first time from the rhizomes of Hedychium gardnerianum Rosc.
TL;DR: The xanthone 3 was confirmed through of co-injection HRGC-MS of the respective extract with a certified standard obtained by methylation of 2 with diazomethane.
Abstract: Polygala paniculata L yielded the xanthones 1-hydroxy-5-methoxy-2,3-methylenedioxyxanthone (1) and 1,5-dihydroxy-2,3-dimethoxyxanthone (2), together with coumarin murragatin and flavonol rutin Their structures were established by chemical and spectroscopic methods (EIMS, IR, 1H and 13C NMR, NOE difference spectroscopy) By posterior analysis of an apolar crude extract using high resolution gas chromatography coupled to mass spectrometry (HRGC-MS) it was possible to characterize two sterol (spinasterol and delta25-spinasterol) and the minor 1-hydroxy-2,3,5-trimethoxyxanthone (3) Thus, the xanthone 3 was confirmed through of co-injection HRGC-MS of the respective extract with a certified standard obtained by methylation of 2 with diazomethane
TL;DR: Combination of a xanthone and crown ether provides a receptor that extracts phenylalanine from water and the ninhydrin test was used to assess the amount of other amino acids extracted by this receptor.
TL;DR: In this paper, the photoinitiated reaction between vitamin C and xanthone in SDS, hexadecyltrimethylammonium chloride (CTAC), and Triton X-100 micelle solutions at various pH was investigated by time-resolved electron paramagnetic resonance (TR-EPR).
Abstract: The photoinitiated reaction between vitamin C and xanthone in sodium lauryl sulfate (SDS), hexadecyltrimethylammonium chloride (CTAC), and Triton X-100 micelle solutions at various pH was investigated by time-resolved electron paramagnetic resonance (TR-EPR). The TR-EPR spectra were explained by superimpositions of the xanthone ketyl and the vitamin C radicals, showing that a fast hydrogen abstraction reaction of the excited xanthone from vitamin C progresses around the water−oil interface region of the micelles. The EPR signal intensity of the vitamin C radical showed the notable pH dependence, which seems to be attributable to the acid−base dissociation equilibrium of vitamin C. The results suggested that the present reaction is controlled by the transportation of the excited xanthone and vitamin C to the reaction-progressing region, which is the surface or inside of the micelle, and by the difference of the reactivity between the dissociation forms of vitamin C.
TL;DR: In this article, xanthone compounds isolated from Swertia przewalskii pissjauk were well separated by capillary electrophoresis within 5 min, using a running buffer of 25 mM disodium tetraborate at pH 9.0.
Abstract: Pharmacologically active xanthone compounds isolated from Swertia przewalskii pissjauk were well separated by capillary electrophoresis (CE) within 5 min, using a running buffer of 25 mM disodium tetraborate at pH 9.0. Quantitative determination was shown to be possible because regression equations revealed a linear relationship between the peak area of each constituent and its concentration, with correlation coefficients of 0.9972-0.9994. The relative standard deviations were between 0.44%-0.73% for migration times and 2.52%-4.28% for peak areas. The dissociation constant of 1,7-O-beta-D-glucopyranosyl-8-hydroxy-3,7-dimethoxyxanthone, 1,8-dihydroxy-3, 7-dimethoxy-xanthone and 1,7-dihydroxy-3,8-dimethoxyxanthone were also measured by the CE method, giving a value of 9.04, 8.94, and 8.59, respectively.
TL;DR: A new xanthone 1,3,6-trihydroxy-8methoxyxanthone, was isolated from chloroform extract of the whole plant of Hoppea fastigiata and the structure was elucidated on the basis of spectroscopic and chemical studies as mentioned in this paper.
Abstract: A new xanthone 1,3,6-trihydroxy-8-methoxyxanthone, was isolated from chloroform extract of the whole plant of Hoppea fastigiata and the structure was elucidated on the basis of spectroscopic and chemical studies. The xanthone molecule has an unusual oxygenation pattern (1,3,6, 8) and is of chemotaxonomic interest.
Journal Article•
TL;DR: Compounds VIII and IX were isolated from Swertia davidi Franch, for the first time, whereas compound X is a new xanthone, named daviditin B with antioxygenated activity in vitro.
Abstract: AIM To study the active constituents of Swertia davidi Franch. METHODS Chemical components were isolated by column chromatography and their structures were established mainly by spectroscopic means (UV, IR, NMR, 2D-NMR, MS). RESULTS Three substances were identified as 2,5-dimethoxyl-1, 4-dicarboxyl benzene (VIII), 1,5,8-trihydroxyl-3,4-dimethoxyl xanthone (IX) and 1,8-dihydroxyl-3-(3'-hydroxyl-butoxy) xanthone (X). CONCLUSION Compounds VIII and IX were isolated from Swertia davidi Franch, for the first time, whereas compound X is a new xanthone, named daviditin B with antioxygenated activity in vitro.
TL;DR: The crystal structure of 1,5-dihydroxy xanthone obtained from Callophyllum trapezifolium has been determined (C13H8O4), Mr = 228.21, a = 5.547(5), b = 4.186 (5), c = 16.487(5) A, β = 91.40(1)○, Z = 2 and V = 474.1(6) A3 as mentioned in this paper.
Abstract: The crystal structure of 1,5-dihydroxy xanthone obtained from Callophyllum trapezifolium has been determined (C13H8O4), Mr = 228.21, a = 5.547(5), b = 5.186(5), c = 16.487(5) A, β = 91.40(1)○, Z = 2 and V = 474.1(6) A3. The xanthone molecule is planar and exhibits rotational disorder in the crystal. The packing of the molecules in the crystal lattice is due to inter- and intramolecular O–H⋅ ⋅ ⋅O hydrogen bonds forming infinite chains.
Journal Article•
TL;DR: Ho et al. as mentioned in this paper identified xanthone derivatives from medicinal plant Swertia mileensis using extensive silica gel column chromatography and their structures were elucidated by chemical evidences and spectral analysis.
Abstract: Object Isolation and structural identification of xanthone derivative from medicinal plant Swertia mileensis T N Ho et W L Shih were carried out Methods The chemical constituents were isolated and purified by extensive silica gel column chromatography and their structures were elucidated by chemical evidences and spectral analysis Results There were 12 xanthone analogues named 1 hydroxy 2, 3, 4, 5 tetramethoxyxanthone, (Ⅰ); 1 hydroxy 2, 3, 7 trimethoxyxanthone, (Ⅱ); 1 hydroxy 2, 3, 5, 7 tetramethoxyxanthone, (Ⅲ); 1, 5 dihydroxy 2, 3 dimethoxyxanthone, (Ⅳ); 1, 5 dihydroxy 2, 3, 7 trimethoxyxanthone, (Ⅴ); 1 hydroxy 2, 3, 5 trimethoxyxanthone, (Ⅵ); 1, 5 dihydroxy 2, 3, 4, 7 tetramethoxyxanthone, (Ⅶ); 1, 8 dihydroxy 2, 3, 6 trimethoxyxanthone, (Ⅷ); 1 hydroxy 2, 3, 4, 7 tetramethoxyxanthone, (Ⅸ); 1, 2, 3, 5 tetromethoxyxanthone, (Ⅹ); 1 hydroxyl 2, 3, 4, 6 tetramethoxyxanthone, (Ⅺ); 1 hydroxyl 2, 3, 6, 8 tetramethoxyxanthone, ( ⅩⅡ ) Conclusion Compounds Ⅰ, Ⅲ, Ⅳ, Ⅴ, Ⅶ ⅩⅡ were first isolated from S. mileensis
Journal Article•
TL;DR: It was established that xanthone glycoside (II) is superior to (I) with respect to cholagogic effect and is inferior to (III) and (IV) with help of cholatostimulant action.
Abstract: Comparative data are presented for the choleretic activity of xanthones isolated from Gentianopsis barbata (Froel.) Ma. (Gentianaceae family): a sum of xanthone glycosides (I) and aglycons (II); xanthone aglycons, including decussatin [1-(OH)-3,7,8-(OCH3)3] (III) and gentiacaulein [1,7-(OH)-3,8-(OCH3)2] (IV); and xanthone glycoside gentiabavaroside [1-O-primverosyl-7-(OH)-3,8-(OCH3)2] (V). It was established that (II) is superior to (I) with respect to cholagogic effect and is inferior to (III) and (IV) with respect to cholatostimulant action.
Patent•
23 Jul 2003
TL;DR: In this article, a kind of 11-carboxypropyl substituted benzo [a] xanthone compounds is prepared from substituted binaphthol through catalytic reaction under existance of water and copper-amine complex as catalyst toobtain 1-oxy-13c-hydroxy-1,13-dihydro-dibenzo compound, and optical open-loop synthesizing respectively in water, alcohol, and ammonia (or amine) contained system.
Abstract: A kind of 11-carboxypropyl substituted benzo [a] xanthone compounds is prepared from substituted binaphthol through catalytic reaction under existance of water and copper-amine complex as catalyst toobtain 1-oxy-13c-hydroxy-1,13-dihydro-dibenzo [a,kl] xanthene compound, and optical open-loop synthesizing respectively in water, alcohol, and ammonia (or amine) contained system.
Journal Article•
TL;DR: Two new xanthone glycosides, 3-O-beta-D-glucopyranosyl-1,6-dihvdroxy Xanthone 1 and 3-C-beta-,D-GLU-1-hydroxy-7-methoxvxanthone 2 have been isolated from the aerial parts of Gentiane, tizzuensis.
Abstract: Two new xanthone glycoside, 3-O-beta-D-glucopyranosyl-1,6-dihvdroxy xanthone 1 and 3-C-beta-D-glucopyranosyl-1-hydroxy-7-methoxvxanthone 2 have been isolated from the aerial parts of Gentiane, tizzuensis. Their structures have been established by spectroscopic studies (FABMS, H-1 NMR, C-13 NMR, DEPT and COSY) and by comparison with closely related compounds.
TL;DR: In this article, the results of the reaction of fluoren-9-ylidene-3-thioxopropanenitrile with nitrile 3 were shown to give dipolar adducts.
Abstract: Lawesson's reagent reacts with xanthen-9-ylidenemalono-nitrile 3 to give adducts 5a, 6a and 7, respectively. In case of the reaction of fluoren-9-ylidenemalononitrile 4 with j[, only 3-amino-2-fluoren-9-ylidene-3-thioxopropanenitrile 5b is obtained together with trimer 7. Whereas, trisdialkylaminophosphines 2a,b reacts with nitrile 3 to give the dipolar adducts 8 and 9, the corresponding dialkylaminophosphonate adducts 10a and 10b are obtained from the reaction of 2a,b with nitrile 4. Structural reasoning for the new adducts was based on compatible analytical and spectral data.
TL;DR: Combination of a xanthone and crown ether provides a receptor that extracts phenylalanine from water as discussed by the authors, and strong anisotropic shifts were observed for the guest aromatic ring in the complex.
Abstract: Combination of a xanthone and crown ether provides a receptor that extracts phenylalanine from water. Strong anisotropic shifts were observed for the guest aromatic ring in the complex. The ninhydrin test was used to assess the amount of other amino acids extracted by this receptor.
Patent•
27 Dec 2003
TL;DR: In this article, new derivatives of xanthone of the formula (I): R1 represents hydrogen atom, methyl group, C2-C6-alkyl group, acetyl group and -CO-C2-6alkyl groups or CO-C 6-18-aryl group that can be unsubstituted or substituted with OH or O-C 1-6-alkyl group.
Abstract: FIELD: organic chemistry, medicine, oncology, pharmacy. SUBSTANCE: invention relates to new derivatives of xanthone of the formula (I): R1 represents hydrogen atom, methyl group, C2-C6-alkyl group, acetyl group, -CO-C2-6-alkyl group or CO-C6-18-aryl group that can be unsubstituted or substituted with OH or O-C1-6-alkyl group; or counter-cation taken among group including alkaline or alkaline-earth metal cations, such as Li+,Na+;K+,Ca++,Mg++,NR16R17R18R19(+) wherein R16,R17,R18,R19 are taken independently of one another among hydrogen atom or C1-6-alkyl; R2 and R3 form part of the group with double bond C17=C18, or its tautomer, enantiomer, or stereoisomer, or its physiologically acceptable salt, or solvate, or their mixtures. Invention relates also to method for isolation of sootepenseon by extraction from Dasymaschalon sootepense Graib, Annonaceae leaves, its identification and transformation. These compounds show an antitumor activity and can be used as anticancer agents in pharmaceutical composition and in method for tumor growth suppression. Invention provides preparing new compounds eliciting valuable pharmacological properties. EFFECT: improved preparing method, valuable medicinal properties of compounds. 7 cl, 3 tbl, 2 ex
TL;DR: In this paper, a total synthesis of atroviridin (1 ) based on biosynthetic principles is presented. But the synthesis of the natural product was constructed by coupling aryl bromide 8 with aldehyde 7 and subsequent intramolecular conjugate addition on a quinone precursor.
Abstract: A total synthesis of atroviridin ( 1 ) based on biosynthetic principles is presented. The tetracyclic xanthone structure of the natural product was constructed by coupling aryl bromide 8 with aldehyde 7 and subsequent intramolecular conjugate addition on a quinone precursor. Bromide 8 was produced from aldehyde 9 via a sequence of steps involving Baeyer–Villiger oxidation and Claisen cyclization.