Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Xanthones”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources
PubMed2004

Allanxanthone B, a polyisoprenylated xanthone from the stem bark of Allanblackia monticola Staner L.C.

In addition to five known compounds including three xanthones, tovophyllin A, rubraxanthone and garciniafuran, one pentacyclic triterpene, lupeol and one phytosterol, stigmasterol, a polyisoprenylated xanthone named allanxanthone B was isolated from the stem bark of Allanblackia monticola. The structure of the new compound was assigned as 2-geranyl-1,3,6-trihydroxy-2',2'-dimethyl[5',6':7,8]xanthone by means of spectroscopic analysis. The antimicrobial activities of some of these compounds against a range of micro-organisms are also reported.

Anti-Bacterial Agents↗
PubMed2005

Bangangxanthone A and B, two xanthones from the stem bark of Garcinia polyantha Oliv.

Two xanthones, bangangxanthone A (1) [1,5,8-trihydroxy-6'-methyl-6'-(4-methylpent-3-enyl)- pyrano[2',3':3,4]xanthone] and B (2) [1,4,8-trihydroxy-2-prenylxanthone], along with two known xanthones, 1,5-dihydroxyxanthone, 2-hydroxy-1,7-dimethoxyxanthone and the pentacyclic triterpenoids, friedelin, oleanolic acid and lupeol were isolated from the chloroform extract of the stem bark of Garcinia polyantha. The structures of these compounds were assigned by spectroscopic analysis. Compounds 1-4 showed antioxidant DPPH radical scavenging activities.

Biphenyl Compounds↗
PubMed2005

Xanthone derivatives from Cratoxylum cochinchinense roots.

Two xanthones and two caged-prenylated xanthones, named cochinchinones A-D, respectively, and a synthetically known caged-prenylated xanthone, together with seven known compounds were isolated from the roots of Cratoxylum cochinchinense (Lour.) Blume. Their structures were assigned on the basis of analyses of spectroscopic data. Some of the compounds exhibited effective antioxidative properties.

Clusiaceae↗
PubMed2006

Tetraoxygenated xanthones from the fruits of Garcinia cowa.

Tetraoxygenated xanthones, cowaxanthones A-E, together with 10 previously reported tetraoxygenated xanthones, were isolated from the crude hexane extract of the fruits of Garcinia cowa. Cowaxanthone B has previously been reported as a synthetic xanthone. Their structures were elucidated by analysis of spectroscopic data, especially by 1D and 2D NMR. The antibacterial activities of the isolated compounds were also evaluated.

Anti-Bacterial Agents↗
PubMed1994

An antifungal gamma-pyrone and xanthones with monoamine oxidase inhibitory activity from Hypericum brasiliense.

A new gamma-pyrone (hyperbrasilone), three known xanthones (1,5-dihydroxyxanthone, 5-hydroxy-1-methoxyxanthone and 6-deoxyjacareubin) and betulinic acid have been isolated from a dichloromethane extract of stems and roots of Hypericum brasiliense. Their structures were established by spectroscopic methods (UV, EI-MS, 1H and 13C NMR) and that of the gamma-pyrone was confirmed by X-ray crystallography. Hyperbrasilone and the xanthones were all antifungal against Cladosporium cucumerinum, while the three xanthones showed differing degrees of inhibition of monoamine oxidase A and B.

Animals↗
PubMed2002

A prenylated xanthone from Allanblackia floribunda.

A new prenylated xanthone, named allanxanthone A, was isolated from the stem bark of Allanblackia floribunda in addition to known compounds, 1,5-dihydoxyxanthone, 1,5,6-trihydroxy-3,7-dimethoxyxanthone, stigmasterol and stigmasteryl-3-O-beta-D-glucopyranoside. The structure of the new compound was assigned as 1,3,5-trihydroxy-2-(3-methylbut-2-enyl)-4-(1,1-dimethylprop-2-enyl) xanthone, by means of spectroscopic analysis. The 13C NMR spectral data of 1,5-dihydroxyxanthone is reported here for the first time as well as the in vitro cytotoxic activity of xanthone metabolites against the KB cell line.

Cameroon↗
PubMed2003

Xanthones from the bark of Garcinia merguensis.

The bark of Garcinia merguensis yielded 10 xanthones, merguenone, 1,5-dihydroxy-6'-methyl-6'-(4-methyl-3-pentenyl)-pyrano(2',3':3,2)-xanthone, subelliptenone H, 8-deoxygartanin, rheediaxanthone A, morusignin G, 6-deoxyjacareubin, 1,3,5-trihydroxy-4,8-di(3-methylbut-2-enyl)-xanthone, rheediachromenoxanthone and 6-deoxyisojacareubin. The structure of merguenone was determined using spectroscopic techniques, mainly 1D and 2D NMR spectroscopy.

Garcinia↗
PubMed2003

Xanthones from the stem bark of Garcinia nigrolineata.

Nine xanthones, nigrolineaxanthones A-I, together with nine known xanthones, were isolated from the crude methanol extract of the stem bark of Garcinia nigrolineata; two of which have previously been reported as synthetic xanthones. The structures were elucidated by analysis of spectroscopic data, especially using 1D and 2D NMR spectroscopic data.

Garcinia↗
PubMed1998

Xanthones as inhibitors of Epstein-Barr virus activation.

To search for possible antitumor promoters, we carried out a primary screening of 20 xanthones isolated from plants of the Guttiferae family, using their possible inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells. Some of these xanthones, namely 1,3,7-trihydroxy-2-(3-methyl-2-butenyl)xanthone (8), dulxanthone-B (10) and latisxanthone-C (15), were observed to significantly inhibit the EBV-EA activation. The investigation indicated that 8, 10 and 15 might be valuable antitumor promoters.

Antigens, Viral↗
PubMed1999

Antimicrobial activity of xanthones from Calophyllum species, against methicillin-resistant Staphylococcus aureus (MRSA).

During the past 5 years, a considerable number of known and new xanthones from the Calophyllum species of Sri Lanka have been isolated and characterized. We have investigated the antimicrobial activity of Calophyllum xanthones, with a special reference to methicillin-resistant Staphylococcus aureus (MRSA). These activity studies were carried out using the agar plate method. Calozeloxanthone, a xanthone which has been isolated from C. moonii and C. lankensis, showed the highest activity against methicillin-resistant S. aureus (MRSA) strains at a concentration of 8.3 microg/ml. Hence, calozeyloxanthone appears to hold promise as an antimicrobial agent in the treatment of infections with S. aureus, including methicillin-sensitive S. aureus (MRSA), and should be investigated further.

Anti-Bacterial Agents↗
PubMed2002

Antihypertensive and vasorelaxing activities of synthetic xanthone derivatives.

A series of xanthones and xanthonoxypropanolamines have been synthesized. The activity of compounds on cardiovascular system was evaluated. All the compounds tested exhibited effective hypotensive activity in anesthetized rats. An oxypropanolamine side chain substituted at the C-3 position of the xanthone nucleus significantly enhanced the hypotensive activity. In rat thoracic aorta, all the compounds tested significantly depressed the contractions induced by Ca(2+) (1.9mM) in high K+(80mM) medium and the phasic and tonic contractions caused by norepinephrine (3 microM). In the rat thoracic aorta, the phenylephrine- and high K+ -induced 45Ca(2+) influx were both inhibited by a selective xanthone derivative, 13. In addition to the previously reported result of 13, evaluated as beta adrenoceptor blocker, the depressor and bradycardia effects of 9 are independent of the parasympathetic passway. These results suggest that 13 showed inhibitory effects on the contractile response caused by high K+ and norepinephrine in rat thoracic aorta are mainly due to inhibition of Ca(2+) influx through both voltage-dependent and receptor-operated Ca(2+) channels. The vasodilating properties of 13 is due to its calcium channel and beta adrenergic blocking effects.

Adrenergic beta-Antagonists↗
PubMed2002

Synthesis and in vivo modulatory activity of protein kinase C of xanthone derivatives.

The modulatory activity of a series of 20 simple xanthones on isoforms alpha, betaI, delta, eta and zeta of protein kinase C (PKC) was evaluated using an in vivo yeast phenotypic assay. Hydroxy and/or methoxyxanthones were synthesised. The majority of these compounds caused an effect compatible with activation of PKC and some showed to be more effective than the standard PKC activator (PMA or arachidonic acid). The xanthones tested differ in their efficacy and potency towards individual PKC isoforms and some showed higher selectivities for PKC-delta, -eta or -zeta, suggesting that xanthone derivatives can become valuable research tools to elucidate the physiological roles of these isoforms.

Animals↗
PubMed2002

Xanthones as inhibitors of growth of human cancer cell lines and their effects on the proliferation of human lymphocytes in vitro.

Twenty-seven oxygenated xanthones have been assessed for their capacity to inhibit in vitro the growth of three human cancer cell lines, MCF-7 (breast cancer), TK-10 (renal cancer) and UACC-62 (melanoma). The effect of these xanthones on the proliferation of human T-lymphocytes was also evaluated. Differences on their potency towards the effect on the growth of the human cancer cell lines as well as on the proliferation of human T-lymphocytes can be ascribed to the nature and positions of the substituents on the xanthonic nucleus.

Adjuvants, Immunologic↗
PubMed2002

Methoxylated xanthones in the quality control of small centaury (Centaurium erythraea) flowering tops.

In the course of a phytochemical study of the bitter tonic plant, small centaury (Centaurium erythraea), six methoxylated xanthones (1,5-hydroxy-3-methoxyxanthone, 1-hydroxy-3,5,6-trimethoxyxanthone, 1-hydroxy-3,5,6,7-tetramethoxyxanthone, 1-hydroxy-3,5,6,7,8-pentamethoxyxanthone, 1-hydroxy-3,7,8-trimethoxyxanthone and 1,8-dihydroxy-3,5,6,7-tetramethoxyxanthone) were isolated and identified by spectroscopic means (nuclear magnetic resonance, mass spectroscopy, and UV). Subsequently, a high-performance liquid chromatography/diode array detection method was developed for the determination of these and other methoxylated xanthones occurring in the chloroform extract of small centaury aerial parts. The methodology developed was applied to twelve samples, and in all of them, nine xanthones were identified and quantified. This methodology can be considered complimentary to the one proposed by the European Pharmacopoeia.

Centaurium↗
PubMed2002

Chemical constituents of Calophyllum brasiliensis: structure elucidation of seven new xanthones and their cancer chemopreventive activity.

The first study of chemical constituents of the stem bark of Calophyllum brasilienses collected in Brazil has led to the isolation and identification of seven new xanthones named brasixanthones A (1), B (4), C (5), D (6), E (2), F (3), and G (10), together with 10 known xanthones. Among the xanthones isolated in this study, 4, 5, 6, and 11 were found to exhibit significant inhibitory activity against 12-O-tetradecanoylphorbol-13-acetate induced Epstein-Barr virus early antigen activation in Raji cells.

Antigens, Viral↗
PubMed2002

Xanthones from the green fruit hulls of Garcinia mangostana.

Three new xanthones, mangostenol (1), mangostenone A (2), and mangostenone B (3), were isolated from the green fruit hulls of Garcinia mangostana, along with the known xanthones, trapezifolixanthone, tovophyllin B (4), alpha- and beta-mangostins, garcinone B, mangostinone, mangostanol, and the flavonoid epicatechin. The structures of the new xanthones were elucidated by analysis of their spectroscopic data.

Catechin↗
PubMed2003

Caged-triprenylated and -tetraprenylated xanthones from the latex of Garcinia scortechinii.

The latex of Garcinia scortechinii has yielded eight new caged-polyprenylated xanthones: two triprenylated (1 and 2) and five tetraprenylated xanthones (3-7) and one degraded caged-tetraprenylated xanthone (8), together with the known scortechinones A (9) and B (10). Their structures were elucidated by analysis of spectroscopic data and comparison of the NMR data with those reported previously.

Bridged-Ring Compounds↗
PubMed2003

Antibacterial xanthones from the leaves of Garcinia nigrolineata.

Ten new 1,3,5-trioxygenated xanthones, nigrolineaxanthones J-S (1-10), one new quinone derivative, nigrolineaquinone A (11), and one new isoflavone-like compound, nigrolineaisoflavone A (12), were isolated from the leaves of Garcinia nigrolineata along with four known xanthones and friedelin. Among the xanthones, only nigrolineaxanthone N (5) showed significant antibacterial activity against methicillin-resistant Staphylococcus aureus.

Anti-Bacterial Agents↗