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PubMed2005

Benzopyran, biphenyl, and tetraoxygenated xanthone derivatives from the twigs of Garcinia nigrolineata.

One new benzopyran, nigrolineabenzopyran A (1), two new biphenyls, nigrolineabiphenyls A and B (2, 3), and four new tetraoxygenated xanthones, nigrolineaxanthones T-W (4-7), were isolated from the crude methanol extract of the twigs of Garcinia nigrolineata along with 11 known xanthones. The xanthones isolated from the twigs as well as those from the stem bark were evaluated for antibacterial activity against methicillin-resistant Staphylococcus aureus. Nigrolineaxanthone F, latisxanthone D, and brasilixanthone showed significant activity, with an equal MIC value of 2 microg/mL.

Anti-Bacterial Agents↗

PubMed2002

Xanthones and secoiridoids from hairy root cultures of Centaurium erythraea and C. pulchellum.

Shoots of Centaurium erythraea and C. pulchellum were inoculated with suspension of Agrobacterium rhizogenes cells, strain A4M70GUS. Five clones of C. erythraea hairy roots (A-E) and three clones of C. pulchellum hairy roots (F-H) were selected according to morphological differences. Spontaneous bud initiation occurred in clones C, D, G and H. Hairy roots retained the capacity for xanthone biosynthesis, with some variation being observed between individual clones. The concentration of xanthones in hairy roots was higher than that in naturally occurring plants. In transgenic plants both, secoiridoid and xanthone compounds were detected.

Centaurium↗

PubMed2006

Cytotoxic and anti-HIV-1 caged xanthones from the resin and fruits of Garcinia hanburyi.

Three new caged xanthones, 7-methoxydesoxymorellin (1), 2-isoprenylforbesione (2) and 8,8a-epoxymorellic acid (3), together with nine known caged xanthones were isolated from the EtOAc extracts of resin and fruits of Garcinia hanburyi. The structures were determined by spectroscopic methods. Most of the isolated compounds showed significant cytotoxicities against a panel of mammalian cancer cell lines. Compound 3, together with the known compounds desoxymorellin, morellic acid, gambogic acid, hanburin, forbesione and dihydroisomorellin, exhibited anti-HIV-1 activity in the reverse transcriptase (RT) assay while the known compounds desoxygambogenin and dihydroisomorellin were found moderately active in the syncytium assay. This work represents the first report on the anti-HIV-1 activities of caged xanthones.

Animals↗

PubMed1994

Xanthones of Garcinia cowa.

Five xanthones have been isolated from Garcinia cowa Roxb. (Guttiferae): cowanin (1), cowanol (2), cowaxanthone (3), 1,3,6-trihydroxy-7-methoxy- 2-5-bis(3-methyl-2-butenyl)xanthone (4), and norcowanin (5). The structures were assigned by spectroscopic studies. Xanthones 2 and 3 showed moderate antimicrobial activity against Staphylococcus aureus.

Anti-Bacterial Agents↗

PubMedDate not supplied

New flavonol glycosides and new xanthone from Polygala japonica.

Three new flavonol glycosides and a new xanthone were isolated from Polygala japonica HOUTT. with eight known compounds. Their structures were identified as 1,7-dihydroxy-3,4-dimethoxy-xanthone (1), kaempferol-7,4'-dimethyl ether (2), physcion (3), guazijinxanthone (4), rhamnetin (5), polygalin A (6), 3,5,7-trihydroxy-4'-methoxy-flavone-3-O-beta-d-galactopyranoside (7), 3,5,3'-trihydoxy-7,4'-dimethoxy-flavone-3-O-beta-d-galactopyranoside (8), 3,5,3',4'-tetrahydroxy-7-methoxy-flavone-3-O-beta-d-galactopyranoside (9), 3,5,3',4'-tetrahydroxy-7-methoxy-flavone-3-O-beta-d-glucopyranoside (10), polygalin B (11), polygalin C (12). Among them, compound 4 is a new xanthone, and 6, 11 and 12 are new flavonol glycosides. Compounds 1, 4, 7 and 8 were tested for cytotoxic activity with MTT assays on five human tumor cell lines, K562, A549, PC-3M, HCT-8 and SHG-44. Compound 4 showed cytotoxic activity against all the five cell lines.

Antineoplastic Agents, Phytogenic↗

PubMed2006

Two new xanthone diglycosides from Swertia longifolia Boiss.

From aerial parts of Swertia longifolia Boiss., which grows in the north of Iran, five xanthones, two of which in diglycosidic form, were isolated. The structures were confirmed by means of their spectral data as isobellidifolin, bellidin, gentisein, 1,5-dihydroxy-3-methoxy-6-O-primeverosyl xanthone, and 8-hydroxy-3,5-dimethoxy-1-O-primeverosyl xanthone, the latter two of which were new derivatives in the plant kingdom.

Glycosides↗

PubMed1996

Antibacterial activity of xanthones from guttiferaeous plants against methicillin-resistant Staphylococcus aureus.

Extracts of Garcinia mangostana (Guttiferae) showing inhibitory effects against the growth of S. aureus NIHJ 209p were fractionated according to guidance obtained from bioassay and some of the components with activity against methicillin-resistant Staphylococcus aureus (MRSA) were characterized. One active isolate, alpha-mangostin, a xanthone derivative, had a minimum inhibitory concentration (MIC) of 1.57-12.5 micrograms mL-1. Other related xanthones were also examined to determine their anti-MRSA activity. Rubraxanthone, which was isolated from Garcinia dioica and has a structure similar to that of alpha-mangostin, had the highest activity against staphylococcal strains (MIC = 0.31-1.25 micrograms mL-1), an activity which was greater than that of the antibiotic vancomycin (3.13-6.25 micrograms mL-1). The inhibitory effect against strains of MRSA of two of the compounds when used in conjunction with other antibiotics was also studied. The anti-MRSA activity of alpha-mangostin was clearly increased by the presence of vancomycin; this behaviour was not observed for rubraxanthone. The strong in-vitro antibacterial activity of xanthone derivatives against both methicillin-resistant and methicillin-sensitive Staphylococcus aureus suggests the compounds might find wide pharmaceutical use.

Anti-Bacterial Agents↗

PubMed2003

Prenylated xanthones from Garcinia xanthochymus.

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.

Animals↗

PubMed2006

Cytotoxic polyprenylated xanthones from the resin of Garcinia hanburyi.

Thirteen xanthones (1-13) were isolated from the resin of Garcinia hanburyi. Among them, two new compounds (namely gaudichaudic acid, and isogambogenic acid, 1, 2), and one new natural product (deoxygaudichaudione A, 3) were identified on the basis of extensive spectral evidence including detailed 2D NMR data. Ten of these xanthones were tested for their cytotoxicities against human leukemia K562 (K562/S) and doxorubicin-resistant K562 (K562/R) cell lines, and showed similar inhibitory effects on both cell lines, suggesting that this group of polyprenylated xanthones might not be multidrug resistance (MDR) substrates.

Antineoplastic Agents, Phytogenic↗

PubMed2004

[Structural characteristics and spectroscopic profiles of xanthones from Polygala].

Through studies of xanthones from Polygla tenuifolia, one of the main medicinal plants of Polygala, the structural characteristics and spectroscopic rules (including IR, UV, (1)H NMR and (13)C NMR data) of xanthones from Polygala were summarized, combined with the reference reports of this type of compounds from the other plants of Polygala. It is helpful to the structure elucidation of xanthones.

Magnetic Resonance Spectroscopy↗

PubMed2004

[Xanthones from Tibetan medicine Halenia elliptica and their antioxidant activity].

OBJECTIVE: To investigate the xanthones from Tibetan medicine Halenia elliptica and their antioxidant activity. METHODS: Column chromatography over normal phase silica gel, reversed phase silica gel, Sephadex LH-20, and recrystallization techniques were used to isolate and purify constituents from Halenia elliptica. Infrared spectrometry, mass spectrometry, and nuclear magnetic resonance spectrometry were used to identify the structure of compounds. The antioxidant activity was evaluated by measuring the content of malondialdehyde product in mice liver cell microsomal induced by ferrous-cysteine. RESULTS: Eight xanthones (compound I-VIII) were isolated and identified from the ethyl acetate extract of Halenia elliptica, among which 1,7-dihydroxy-2,3,5-trimethoxyxanthone was a novel compound. Compound I, III at 10 microg/ml and 100 microg/ml could inhibit the production of malondialdehyde in mouse liver microsomes in vitro. CONCLUSION: Eight xanthones were isolated and they have certain antioxidant activity.

Antioxidants↗

PubMed1998

Aminoalkanolic derivatives of xanthone with potential antiepileptic activity.

Synthesis, physicochemical and anticonvulsant properties of some aminoisopropanoloxy derivatives of 2-xanthone are described. The compounds were prepared by the amination of 2-[(2,3-epoxy)-propoxyl]-xanthone or 2-(3-chloro-2-hydroxy-propoxy)-xanthone. The obtained compounds were evaluated for anticonvulsant activity in the maximal electroshock (MES)- and subcutaneous pentylenetetrazole (scMet)-induced seizures and for neurotoxicity in the rotorod test in mice and rats. The most promising compounds seem to be the 3-(tert.-butyl-amino) (3), 3-[N-methyl-(tert.-butyl)-amino] (12) and 3-[4-(benzyl)-1-piperazinyl (5) substituted 2-hydroxy-1-(2-xanthonoxy)-propane from which 3 and 5 were active in both the anticonvulsant tests. The protective index (TD50/ED50) in MES in mice for 3 and valproate, as for 12 and phenytoin or carbamazepine, is similar.

Animals↗

PubMed2000

Characterization of prenylated xanthones and flavanones by liquid chromatography/atmospheric pressure chemical ionization mass spectrometry.

Reversed-phase liquid chromatography with atmospheric pressure chemical ionization mass spectrometry (LC/APCI-MS) in the positive-ion mode was utilized to analyze crude ether extracts from the root bark of Maclura pomifera, a tree known to have a high content of prenylated xanthones and flavanones. Identification of three xanthones and two flavanones was based on their unique mass spectra. Under optimum conditions peaks corresponding to the [MH](+) ion and characteristic fragments for each compound were observed. (1)H NMR data were used to confirm the identities of two xanthones that had the same molecular mass and similar fragmentation patterns. Fragmentation of the analytes was achieved by application of an electrostatic potential at the entrance of the single quadrupole mass spectrometer. The optimum voltage for fragmentation was found to be related to the class of compounds analyzed and, within each class, to be dependent on the structure of the prenyl moiety. Collision-induced pathways consistent with precedent literature describing the MS characterization of similar compounds and with the observed fragmentation patterns are tentatively proposed.

Chromatography, Liquid↗

PubMed1993

gamma-Pyrone compounds. IV: Synthesis and antiplatelet effects of mono- and dioxygenated xanthones and xanthonoxypropanolamine.

Xanthodilol, mono- and dioxygenated xanthones, and 1,3-, 2,3-, 3,4-, 3,5-, 1,6-, 2,6- and 3,6-dioxygenated xanthones were synthesized from benzophenone precursors by Friedel-Crafts acylation and subsequent base-catalyzed cyclization to eliminate methanol. 3-Hydroxy-xanthone, xanthodilol, 2,3-dihydroxyxanthone diacetate, and 3,4-dihydroxyxanthone and its diacetate showed potent antiplatelet effects on arachidonate- and collagen-induced aggregation. 3,5-Dihydroxyxanthone and its diacetate, 1,6-dimethoxyxanthone, and 3,6-dihydroxyxanthone and its diacetate showed potent antiplatelet effects on arachidonate-induced aggregation.

Adenosine Diphosphate↗

PubMed2006

Photodecarboxylation of xanthone acetic acids: C-C bond heterolysis from the singlet excited state.

[reaction: see text] Irradiation of 2- and 4-xanthone acetic acid in aqueous buffer (pH 7.4) leads to efficient (Phi = 0.67 and 0.64, respectively) photodecarboxylation to give the corresponding methyl products, consistent with an intermediate benzylic carbanion. Fluorescence and laser flash photolysis (LFP) studies suggest singlet state reactivity, which is unusual for aromatic ketones. 3-Xanthone acetic acid is photoinert under the same conditions. The results suggest that the reactive xanthone acetic acids are promising precursors for carbanion-mediated photocages.

Journal Article↗

PubMed2004

Antimicrobial activity of hydrophobic xanthones from Cudrania cochinchinensis against Bacillus subtilis and methicillin-resistant Staphylococcus aureus.

Ten xanthones with one or two isoprenoid groups and a prenylated benzophenone isolated from roots of Cudrania cochinchinensis (Moraceae) were tested for their antimicrobial activities against Bacillus subtilis and methicillin-resistant Staphylococcus aureus (MRSA). Among these compounds, gerontoxanthone H exhibited considerable antibacterial activity against B. subtilis (MIC = 1.56 microg/ml). Four xanthones, gerontoxanthone I, toxyloxanthone C, cudraxanthone S, and 1,3,7-trihydroxy-2-prenylxanthone, showed weak antibacterial activity against the bacterium (MICs = 3.13-6.25 microg/ml). These compounds also exhibited similar MIC values against methicillin-sensitive S. aureus, MRSAs, and Micrococcus luteus.

Anti-Infective Agents↗

PubMed2005

Isoprenylated xanthones and flavonoids from Cudrania tricuspidata.

Further phytochemical investigation on the roots of Cudrania tricuspidata afforded a new isoprenylated xanthone, cudratricusxanthone I (1), two new isoprenylated flavanones, cudraflavanones C and D (2 and 3, resp.), and seven known compounds, 1,7-dihydroxy-3,6-dimethoxyxanthone (4), macluraxanthone C (5), cudraxanthones E, K, and L (6, 7, and 8, resp.), cudraflavanone A (9), and cudraflavone C (10). Their structures were identified by spectroscopic methods. Cudratricusxanthone H (12), macluraxanthone B (13), two xanthones previously isolated from this plant, and 5, showed significant inhibitory effects on four kinds of human digestive apparatus tumor cell lines (HCT-116, SMMC-7721, SGC-7901, and BGC-823) with IC50 values of 2.70-12.66 microM.

Antineoplastic Agents, Phytogenic↗

PubMed2006

Liquid chromatography/tandem mass spectrometric study and analysis of xanthone and secoiridoid glycoside composition of Swertia chirata, a potent antidiabetic.

Swertia chirata is a bitter plant, used in the Indian system of medicine (Ayurveda) for various human ailments. The bioactive constituents include the xanthone and secoiridoid glycosides consisting of mangiferin, amarogentin, amaroswerin, sweroside and swertiamarin. Methanolic extracts of S. chirata possess constituents with antidiabetic activities, which was investigated by high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS). Preliminary HPLC analyses were performed on a reversed-phase C18 column using gradient elution. In the LC/ESI-MS spectra, predominant [M+H]+ and [M+Na]+ ions were observed in positive ion mode and provided molecular mass information. The five components of S. chirata were structurally correlated and confirmed based on the fragmentation characteristics and information available in the literature. The fragmentation behavior of [M+H]+/[M+Na]+ ions of these components were deduced from the collision-induced dissociation (CID) spectra obtained from the selective on-column information-dependant acquisition (IDA) approach. Xanthone-C-glycoside showed characteristic fragment ions due to fragmentation in the C-glycosidic unit while iridoid-O-glycosides showed characteristic fragment ions due to cleavage in the glycoside linkage and retro-Diels-Alder (RDA) cleavage within an iridoid aglycone. Furthermore, on the basis of this information, an analytical assay was developed and validated to determine relative concentrations of mangiferin, amarogentin, amaroswerin, sweroside and swertiamarin. The detection was carried out using multiple reaction monitoring (MRM) in positive ionization mode with a total analysis time of 3.5 min. The method was successfully applied to standardize four different batches of herbal preparation on the basis of relative concentration of five bioactive components.

Chromatography, Liquid↗