Showing papers on "Xanthone published in 2007"
TL;DR: Investigation of the fungal strain Monodictys putredinis isolated from the inner tissue of a marine green alga led to the isolation of four new monomeric xanthones and a benzophenone, which were examined for their cancer chemopreventive potential.
Abstract: Investigation of the fungal strain Monodictys putredinis isolated from the inner tissue of a marine green alga led to the isolation of four new monomeric xanthones and a benzophenone. All structures were elucidated by extensive spectroscopic measurements. The relative configuration of compound 1 was determined by X-ray crystal structure analysis, while for 2 and 3 configurations were confirmed by NOE experiments. Absolute configurations for compounds 1−3 were deduced by comparing experimental circular dichroism spectroscopic data with those calculated employing quantum-chemical time-dependent density functional theory (TDDFT). The compounds were examined for their cancer chemopreventive potential. Xanthone 2 was shown to inhibit cytochrome P450 1A activity with an IC50 value of 3.0 μM. Compounds 2 and 3 displayed moderate activity as inducers of NAD(P)H:quinone reductase (QR) in cultured mouse Hepa 1c1c7 cells, with CD values (concentration required to double the specific activity of QR) of 12.0 and 12.8 ...
92 citations
TL;DR: The here described HPLC-method enables the determination of all major, currently known bioactive compounds in gentian roots and analysis of several commercially available G. lutea samples showed that gentiopicroside is the most dominant compound in the specimens.
72 citations
TL;DR: Another xanthone compound 9, 1,3-di(2',3'-epoxypropoxy)xanthone, was synthesized and its DNA cross-linking property including other two biological activities investigated showed compound 9 possessed excellent cytotoxic and topoisomerase II inhibitory activity than other compounds tested.
67 citations
TL;DR: A series of xanthone derivatives with extended pi-systems, that is, benzoxanthones 2-4, and their structurally perturbed analogs 5-9 have been designed and synthesized as alpha-glucosidase inhibitors.
66 citations
TL;DR: colorimetric analysis coupled with UV-vis and IR spectroscopic analysis demonstrated that the fractions with high alpha-AI activity are primarily oligomeric proanthocyanidins (OPCs) with little gallate moiety, and there is evidence to show that thealpha-AI by these OPCs is not purely by nonspecific protein complexation.
Abstract: Alpha-amylase inhibitor (alpha-AI) activity of Garcinia mangostana, commonly known as mangosteen, pericarp extracts was studied by assay guided fractionations from lipophilic to hydrophilic using combined solvent extraction and Amberlite XAD2 adsorption chromatography. Neither the lipophilic, xanthone containing fraction, nor the highly polar fraction, which has no affinity on Amberlite XAD2, showed any alpha-AI. The fraction that shows very high inhibitory activity contains primarily polyphenols and can be adsorbed on Amberlite XAD2. The IC50 of 5.4 microg/mL of this fraction is comparable to that of acarbose, a prescribed alpha-AI used in the control of type II diabetes, at 5.2 microg/mL. Total phenolic content (TPC) of each fraction was measured and the TPC has no correlation with the alpha-AI activity. The lipophilic fraction contains mainly xanthones as revealed by HPLC-MS analysis. Colorimetric analysis coupled with UV-vis and IR spectroscopic analysis demonstrated that the fractions with high alpha-AI activity are primarily oligomeric proanthocyanidins (OPCs) with little gallate moiety. There is also evidence to show that the alpha-AI by these OPCs is not purely by nonspecific protein complexation. Both tannic acid and G. mangostana OPCs precipitate BSA equally well but G. mangostana OPCs are 56 times more effective in inhibiting alpha-amylase.
46 citations
TL;DR: Significant cytotoxicity against MDA-MB-231, CaOV-3, MCF-7 and HeLa cancer cell-lines was demonstrated by cantleyanones B-D, 7-hydroxyforbesione, deoxygaudichaudione A and macranthol, with IC(50) values ranging from 0.22 to 17.17 microg/ml.
43 citations
TL;DR: In this article, xanthones 1-8 isolated from the root of C. tricuspidata possess highly potent alpha-glucosidase inhibition properties, which is the first natural xanthone documented to exhibit such inhibition.
41 citations
TL;DR: Two new compounds showed moderate inhibitory effect on human breast cancer MDA-MB-435S cell line and their structures were identified on the basis of extensive spectral evidence including detailed 2D NMR and HR-MS data.
Abstract: Two new xanthones, 1,5,6-trihydroxy-6',6'-dimethyl-2H-pyrano(2',3':3,4)-2-(3-methylbut-2-enyl)xanthone (1) and 1,6,7-trihydroxy-6',6'-dimethyl-2H-pyrano(2',3':3,2)-4-(3-methylbut-2-enyl)xanthone (2), have been isolated from the stem bark of Garcinia lancilimba (Guttiferae), together with six known xanthones. Their structures were identified on the basis of extensive spectral evidence including detailed 2D NMR and HR-MS data. Two new compounds showed moderate inhibitory effect on human breast cancer MDA-MB-435S cell line.
32 citations
TL;DR: Two biflavonoids and a prenyltated xanthone isolated from the fruits of Garcinia dulcis exhibited strong antioxidation effects in both Fe2+-mediated and non-metal induced human low-density lipoprotein (LDL) oxidations, however, a well-known antioxidant, α-tocopherol (vitamin E), was found less potent than both compounds based on the same test systems.
26 citations
TL;DR: Two new prenylated anthraquinones were isolated from the seeds of Vismia laurentii together with four known compounds; xanthone V(1) (3), physcion (4), 3-geranyloxyemodin anthrone (5) and friedelin (6).
Abstract: Two new prenylated anthraquinones, laurenquinone A (1) and B (2) were isolated from the seeds of Vismia laurentii together with four known compounds; xanthone V 1 (3), physcion (4), 3-geranyloxyemodin anthrone (5) and friedelin (6). The structures of the new metabolites were determined with the help of spectroscopic data including extensive 2D-NMR spectroscopy. The known compounds were identified by comparison of their physical and spectroscopic data with those reported in the literature. Compounds 1, 4 and 5 exhibited moderate algicidal activity against Chlorella fusca and 3 showed moderate activity against the gram-positive bacterium Bacillus megaterium.
25 citations
TL;DR: Three new prenylated xanthones, 1,3,5-trihydroxy-6,7-[2′-(1-methylethenyl)-dihydrofurano]-xanthone (1), 1, 3, 5, trihydroxy 6,7]-2.5 O-prenyl moiety from the leaves of Hypericum ascyron was reported in this article.
Abstract: Three new prenylated xanthones, 1,3,5-trihydroxy-6,7-[2′-(1-methylethenyl)-dihydrofurano]-xanthone (1), 1,3,5-trihydroxy-6,7-[2′-(1-hydroxy-1-methylethyl)-dihydrofurano]-xanthone (2), and 1,3,5-trihydroxy-6-O-prenyl-xanthone (3), together with eight known compounds were isolated from the leaves of Hypericum ascyron. Compound 3 has an O-prenyl moiety, and therefore represents the first reported xanthone to have an O-prenyl moiety from genus Hypericum. The structures of the isolated compounds were established based on spectroscopic data and on a comparison with values for previously identified analogues.
TL;DR: Phytochemical investigation of the leaves of Allanblackia monticola led to the isolation and characterisation of five prenylated xanthones, established on the basis of homo- and hetero-nuclear, one- and two-dimensional, nuclear magnetic resonance.
Abstract: Phytochemical investigation of the leaves of Allanblackia monticola led to the isolation and characterisation of five prenylated xanthones [1,6-dihydroxy-3,7-dimethoxy-2-(3-methylbut-2-enyl)xanthone 1, alpha-mangostin 2, tovophyllin A 3, allanxanthone C 4 and 1,7-dihydroxy-3-methoxy-2-(3-methylbut-2-enyl)xanthone 5], two biflavonoid derivatives (amentoflavone 6 and podocarpusflavone A 7) and one pentacyclic triterpene (friedelan-3-one 8). The structures of these compounds were established on the basis of homo- and hetero-nuclear, one- and two-dimensional, nuclear magnetic resonance. Compounds 2-8 and a crude methanolic extract of A. monticola leaves were each tested for antimalarial activity in vitro, using the chloroquine-sensitive F32 and chloroquine-resistant FcM29 strains of Plasmodium falciparum; the median inhibitory concentrations (IC(50)) recorded varied from 0.7 to 83.5 mug/ml. The cytotoxicities of the compounds and crude extract, against cultures of human melanoma cells (A375), were then investigated, and cytotoxicity/antimalarial IC(50) ratios of 0.6-16.75 were recorded. In tests involving aortic rings from guinea pigs, a crude extract of the leaves of A. monticola was found to induce concentration-dependent vasorelaxation, causing up to 82% and 42% inhibition of noradrenaline- and KCl-induced contractions, respectively. The corresponding values for compounds 2 and 6 when tested against noradrenaline-induced contractions were approximately 18% and 35%, respectively.
TL;DR: Two new xanthones, 7-hydroxydesoxymorellin (1) and isocaledonixanthone D (2), and four known ones, gaudichaudione H, 1,7-dihydroxy-3-methoxy-2-(3-methyl-2-butenyl)xanthone, 1.5-dimethyl-2.
Abstract: Two new xanthones, 7-hydroxydesoxymorellin (1) and isocaledonixanthone D (2), and four known ones, gaudichaudione H, 1,7-dihydroxy-3-methoxy-2-(3-methyl-2-butenyl)xanthone, 1,5-dihydroxy-3-methoxy-...
TL;DR: In this paper, a series of mangiferin derivatives was synthesized and evaluated for their PTP1B inhibitory activity, and some of the screened compounds displayed good PTP 1B inhibition.
Abstract: Protein tyrosine phosphatase 1B (PTP1B) has received much attention due to its pivotal role in type 2 diabetes and obesity as a negative regulator of the insulin signaling pathway. Mangiferin, a xanthone glucoside, has been reported to possess significant antidiabetic activity. In the present study, a series of mangiferin derivatives was synthesized and evaluated for their PTP1B inhibitory activity. Some of the screened compounds displayed good PTP1B inhibitory activity.
TL;DR: The present results suggested the potent antigenotoxic effects of xanthones in mangosteen, which is widely used as health food because of its many pharmacological properties.
Abstract: The inhibitory effects of xanthone on genotoxicity induced by paraquat and NaNO2 in cultured Chinese hamster lung (CHL) cells were examined. Xanthone forms the central core of xanthones. Xanthones are present in mangosteen, which is widely used as health food because of its many pharmacological properties. Paraquat (PQ, a superoxide anion generator) and NaNO2 induce genotoxic effects, including sister chromatid exchange (SCE) and decreased cell cycle rate, in CHL cells. Xanthone inhibited the genotoxic effects of PQ and NaNO2 at concentrations of more than 5 μM. The present results suggested the potent antigenotoxic effects of xanthones in mangosteens.
TL;DR: In this paper, two new xanthone identified as 1,5-diliydroxy-3,6,7-triniethoxy-8-allyloxyxanthone and 1,hydroxy 3,6-diinethoxy-2-β-D-glucopyranoxanthone have been isolated from the metbanolic extract of the bark of Pinus roxburghii and the structure were established on the basis of spectroscopic data and chemical evidences.
Abstract: Two new xanthone identified as 1,5-diliydroxy-3,6,7-triniethoxy-8-allyloxyxanthone and 1-hydroxy-3,6-diinethoxy-2-β-D-glucopyranoxanthone have been isolated from the metbanolic extract of the bark of Pinus roxburghii and the structure were established on the basis of spectroscopic data and chemical evidences.
TL;DR: In this paper, three new oligosaccharide esters named telephioses D (4), E (5), and F (6), and two new xanthone C-glucosides, telephioxanthones A (7) and B (8), together with five known oligosACcharides esters and mangiferin, were isolated from the whole plant of Polygala telephioides and elucidated on the basis of spectral data.
Abstract: Three new oligosaccharide esters named telephioses D (4), E (5), and F (6), and two new xanthone C-glucosides, telephioxanthones A (7) and B (8), together with five known oligosaccharide esters and mangiferin, were isolated from the whole plant of Polygala telephioidesWilld. The structures of the new compounds were elucidated on the basis of spectral data.
TL;DR: Two xanthones, 1,6-dihydroxy-4,5-dimethoxyxanthone (1) and 1,5,6trihydroxy-7,8-di(3-methyl-2-butenyl)-6′,6′-dimethylpyrano(2′,3′:3,4) xanthone as discussed by the authors, were isolated from the bark of Garcinia xanthochymus by normal phase and reverse phase silica gel column chromatography.
TL;DR: Two new xanthones are isolated from the roots of Cudrania fruticosa and their structures were elucidated on the basis of spectral and chemical techniques.
TL;DR: Investigation of the chemical constituents of the root bark of Artocarpus rigidus BLUME subsp.
Abstract: Investigation of the chemical constituents of the root bark of Artocarpus rigidus BLUME subsp. rigidus has led to the isolation of six, structurally diverse phenolic compounds. These included two new compounds with modified skeletons, the flavonoid 7-demethylartonol E (1) and the chromone artorigidusin (2), together with four known phenolic compounds, the xanthone artonol B (3), the flavonoid artonin F (4), the flavonoid cycloartobiloxanthone (5), and the xanthone artoindonesianin C (6). Compounds 1, 4, and 5 exhibited antiplasmodial activity against Plasmodium falciparum. All compounds showed antimycobacterial activity against Mycobacterium tuberculosis, with 4 being the most active compound (MIC 6.25 microg/ml). Compounds 5 and 6 were active against KB cells, whereas 2, 5, and 6 showed varying toxicity to BC cells. Compounds 1-3, 5, and 6 were active in the NCI-H187 cytotoxicity assay, with 3 being the most active compound (IC(50) 1.26 microg/ml).
TL;DR: Findings suggest that O2, H2O2, and iron ions participate in the reaction, possibly enhances the formation of the hydroxyl radical in reaction mixtures of photosensitizers that can produce O2 −·.
Abstract: To clarify the effect of superoxide dismutase (SOD) on the formation of hydroxyl radical in a standard reaction mixture containing 15 microM of xanthone, 0.1 M of 5,5-dimethyl-1-pyrroline N-oxide (DMPO), and 45 mM of phosphate buffer (pH 7.4) under UVA irradiation, electron paramagnetic resonance (EPR) measurements were performed. SOD enhanced the formation of hydroxyl radicals. The formation of hydroxyl radicals was inhibited on the addition of catalase. The rate of hydroxyl radical formation also slowed down under a reduced oxygen concentration, whereas it was stimulated by disodium ethylenediaminetetraacetate (EDTA) and diethyleneaminepentaacetic acid (DETAPAC). Above findings suggest that O(2), H(2)O(2), and iron ions participate in the reaction. SOD possibly enhances the formation of the hydroxyl radical in reaction mixtures of photosensitizers that can produce O(2)(-.).
TL;DR: The property of the lowest excited triplet states of xanthone in acetonitrile was investigated using time-resolved laser flash photolysis at 355 nm.
Abstract: The property of the lowest excited triplet states of xanthone in acetonitrile was investigated using time-resolved laser flash photolysis at 355 nm The transient absorption spectra and the quenching rate constants (kq) of the excited xanthone with several amines were determined Good correlation between lgkq and the driving force of the reactions suggests the electron transfer mechanism, except aniline and 3-nitroaniline (3-NO2-A) which showed energy transfer mechanism With the appearance of ketyl radical, hydrogen atom transfer also happened between xanthone and dimethyl-p-toluidine, 3,5,N,N-tetramethylaniline, N,N-dimethylaniline, and triethylamine Therefore, both electron transfer and H-atom transfer occured in these systems Great discrepancies of kq values were discovered in H-atom abstraction reactions for alcohols and phenols, which can be explained by different abstraction mechanisms The quenching rate constants between xanthone and alcohols correlate well with the α-C-H bonding energy of alcohols
TL;DR: Two new xanthones, 1,5,6-trihydroxy-6',6'-dimethyl-2H-pyrano(2',3':3,4)-2-(3-methylbut-2-enyl)xanthone (1) and 1,6,7-trihexyl-6,6',dimethyl 2H pyrano (2,3:3,2,2)-4-(3]-methyl but-2enyl), have been identified from the stem bark of Garcinia lancilimba
Abstract: Two new xanthones, 1,5,6-trihydroxy-6',6'-dimethyl-2H-pyrano(2',3':3,4)-2-(3-methylbut-2-enyl)xanthone (1) and 1,6,7-trihydroxy-6',6'-dimethyl-2H-pyrano(2',3':3,2)-4-(3-methylbut-2-enyl)xanthone (2), have been isolated from the stem bark of Garcinia lancilimba (Guttiferae), together with six known xanthones. Their structures were identified on the basis of extensive spectral evidence including detailed 2D NMR and HR-MS data. Two new compounds showed moderate inhibitory effect on human breast cancer MDA-MB-435S cell line.
Patent•
28 Sep 2007
TL;DR: In this paper, a tripeptide consisting of cysteine, alanine and cystine bonded to a hydroxy group of the xanthone by an ester bond is presented.
Abstract: PROBLEM TO BE SOLVED: To provide a xanthone derivative having weak side effects and exhibiting excellent collagen-producing activity, and to provide a method for producing the xanthone derivative. SOLUTION: The xanthone derivative having weak side effects and exhibiting excellent collagen-producing activity has -10 mV to -700 mV oxidation-reduction potential. The derivative has a tripeptide consisting of cysteine, alanine and cysteine bonded to a hydroxy group of the xanthone by an ester bond. The cysteine, the alanine and the cysteine are peptide-bonded. The method for producing the derivative includes steps of adding soybean powder and Bacillus natto to a pericarp powder of mangosteen or a Salacia powder, fermenting the resultant mixture, filtering the fermented liquid, and reducing the resultant filtrate using an alkali, the main steps therein being the fermentation step and the alkali reduction step. COPYRIGHT: (C)2009,JPO&INPIT
Patent•
04 Jul 2007
TL;DR: In this paper, a method for producing a xanthone derivative having weak side-effects and having excellent anti-oxidizing actions is presented. But the method is not suitable for the use in cosmetics.
Abstract: PROBLEM TO BE SOLVED: To provide a xanthone derivative having weak side-effects and having excellent anti-oxidizing actions, to provide a method for producing the same, and to provide cosmetics containing the same. SOLUTION: This xanthone derivative having the anti-oxidizing action is a chitosan dimer, a chitosan trimer, or a chitosan polymer comprising 32 xanthone molecules, and is obtained by adding arginine to a crushed product of Garcinia mangostana, heating, and extracting with a vegetable oil, or is obtained by adding an apple juice and a lipase for transesterification to the crushed product of Garcinia mangostana, heating and extracting with a vegetable oil. The method for producing the xanthone derivative comprises a process of adding Bacillus natto to the crushed product of Garcinia mangostana, arginine and soybeans, fermenting the mixture to form a fermented product and extracting the fermented product with a vegetable oil. The cosmetic comprises a composition containing the xanthone derivative and a fruit juice extract. COPYRIGHT: (C)2009,JPO&INPIT
01 Jan 2007
TL;DR: In this paper, a research on the isolation and identification of xanthone from the fruit rind of mangosteen (Garcinia mangostana L.) was carried out.
Abstract: A research on the isolation and identification of xanthone from the fruit rind of mangosteen (Garcinia mangostana L.) was carried out. Extraction was done using maceration with methanol – water solvent and fractionation with n-hexane and ethyl acetate solvent. Column chromatography with silica gel as the stationary phase and n-hexane – ethyl acetate (7 : 3) as the mobile phase was used for the isolation. From the ethyl acetate fraction was obtained GM II-1 isolate (Rf 0,61 ; nhexane – ethyl acetate 7 : 3 as mobile phase) which showed a colour change from reddish brown to yellow under UV light 366 nm after spraying with AlCl3. Identification of the isolate with UV spectrophotometry gave maximum absorptions at wavelengths 241,5, 257,5, 317, 364,5 nm. GC - MS indicated that GM II-1 isolate had a molecular weight of 259, the isolate was presumed to be a xanthone. Keywords: xanthone, Garcinia mangostana L., mangosteen, isolation, identification
Patent•
04 Jul 2007
TL;DR: In this paper, the xanthone derivative that has an inhibitory action on inflammatory cytokine production is a derivative obtained by combining Xanthone with gluconic acid and a carboxylic acid.
Abstract: PROBLEM TO BE SOLVED: To obtain a xanthone derivative that has a weak adverse effect and an excellent inhibitory action on inflammatory cytokine production, to provide a method for producing the same and a food preparation, a cosmetic and an anti-inflammatory agent comprising the same. SOLUTION: The xanthone derivative that has an inhibitory action on inflammatory cytokine production is a derivative obtained by combining xanthone with gluconic acid and a carboxylic acid. The xanthone derivative is acidic, permeates the skin, exhibits an excellent anti-inflammatory action and has high safety. The method for producing the xanthine derivative comprises a process of adding ground soybean and Bacillus natto to ground mangosteen, fermenting the mixture to give a fermented substance and extracting the fermented substance with an acidic aqueous solution. The food preparation and the cosmetic each comprises the xanthone derivative having an inhibitory action on inflammatory cytokine production and a fruit juice essence. The anti-inflammatory agent comprises the xanthone derivative. COPYRIGHT: (C)2009,JPO&INPIT