Showing papers on "Xanthone published in 2004"

New secondary metabolites from the marine endophytic fungus Apiospora montagnei.

Abstract: 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.

Trypanocidal Constituents in Plants 3. Leaves of Garcinia intermedia and Heartwood of Calophyllum brasiliense

Abstract: The constituents of the leaves of Garcinia intermedia and heartwood of Calophyllum brasiliense were investigated based on their trypanocidal activity against epimastigotes of Trypanosoma cruzi, the etiologic agent of Chagas' disease. As the active components, the polyisoprenylated benzophenone derivative guttiferone A and the xanthone 8-desoxygartanin were isolated along with the biflavonoids podocarpusflavone A and amentoflavone, and friedelin from the former. Three xanthones, jacareubin, 6-deoxyjacareubin, and 1,3,5,6-tetrahydroxy-2-(3-methyl-2-butenyl)xanthone from the latter showed activity. The trypanocidal activity of these compounds against trypomastigotes, an infectious form of T. cruzi, was examined as well as gossypol, berberine chloride, and harmine for comparison.

Nutraceutical mangosteen tea

Abstract: A nutraceutical tea composition containing xanthone compounds is disclosed The xanthones contained in the tea composition are, preferably, derived from fruit of the Garcinia mangostana L plant, otherwise known as the mangosteen plant

Search for constituents with neurotrophic factor-potentiating activity from the medicinal plants of paraguay and Thailand.

Abstract: 20 medicinal plants of Paraguay and 3 medicinal plants of Thailand were examined on nerve growth factor (NGF)-potentiating activities in PC12D cells. The trail results demonstrated that the methanol extracts of four plants, Verbena littoralis, Scoparia dulcis, Artemisia absinthium and Garcinia xanthochymus, markedly enhanced the neurite outgrowth induced by NGF from PC12D cells. Furthermore, utilizing the bioactivity-guided separation we successfully isolated 32, 4 and 5 constituents from V. littoralis, S. dulcis and G. xanthochymus, respectively, including nine iridoid and iridoid glucosides (1-9), two dihydrochalcone dimers (10 and 11), two flavonoids and three flavonoid glycosides (12-16), two sterols (17 and 18), ten triterpenoids (19-28), five xanthones (29-33), one naphthoquinone (34), one benzenepropanamide (35), four phenylethanoid glycosides (36-39) and two other compounds (40 and 41). Among which, 15 compounds (1-4, 10-11, 14-18, 29-31 and 34) were new natural products. The results of pharmacological trails verified that littoralisone (1), gelsemiol (5), 7a-hydroxysemperoside aglucone (6), verbenachalcone (10), littorachalcone (11), stigmast-5-ene 3beta,7alpha,22alpha-triol (18), ursolic acid (19), 3beta-hydroxyurs-11-en-28,13beta-olide (24), oleanolic acid (25), 2alpha,3beta-dihydroxyolean-12-en-28-oic acid (26), 1,4,5,6-tetrahydroxy-7,8-di(3-methylbut-2-enyl)xanthone (29), 1,2,6-trihydroxy-5-methoxy-7-(3-methylbut-2-enyl)xanthone (30), 1,3,5,6-tetrahydroxy-4,7,8-tri(3-methyl-2-butenyl)xanthone (31), 12b-hydroxy-des-D-garcigerrin A (32), garciniaxanthone E (33) and (4R)-4,9-dihydroxy-8-methoxy-alpha-lapachone (34) elicited marked enhancement of NGF-mediated neurite outgrowth in PC12D cells. These substances may contribute to the basic study and the medicinal development for the neurodegenerative disorder.

New phenolic principles from Hypericum sampsonii.

Abstract: Using the anti-hepatitis B virus (HBV)-producing cell line MS-G2 in vitro cultural system-guided screening was performed, and two new benzophenones, 2,6-dihydroxy-4-[(E)-5-hydroxy-3,7-dimethylocta-2,7-dienyloxy]benzophenone (1) and 2,6-dihydroxy-4-[(E)-7-hydroxy-3,7-dimethylocta-2-enyloxy]benzophenone (2), a new xanthone, hyperxanthone (3), a new bisanthraquinone glycoside, R-(-)-skyrin-6-O-beta-D-xylopyranoside (4), and 2-caffeoyloxy-3-hydroxy-3-(3,4-dihydroxyphenyl)propyl alcohol (5), and 16 known compounds were isolated from the anti-HBV active fraction of the whole herbs of Hypericum sampsonii. Their structures were elucidated using spectroscopic methods, mainly 2D NMR and MS spectrometry. Circular dichroism was used to determine the stereochemistry of bisanthraquinone glycosides.

A New Ring-Reduced Tetraprenyltoluquinone and a Prenylated Xanthone from Garcinia cowa

Abstract: The methanolic extract of the stem bark of Garcinia cowa Roxb. (Guttiferae) yielded (2E,6E,10E)-(+)-4β-hydroxy-3-methyl-5β-(3,7,11,15-tetramethylhexadeca-2,6,10,14-tetraenyl)cyclohex-2-en-1-one 1, 4-(1,1-dimethyl-prop-2-enyl)-1,5,6-trihydroxy-3-methoxy-2-(3-methylbut-2-enyl)xanthen-9(9H)-one 2, and the known compound rubraxanthone 3. The structural conclusions are based on spectroscopic data.

Symphonin: a new prenylated pyranoxanthone with antimicrobial activity from the seeds of symphonia globulifera (Guttiferae)

Abstract: A new prenylated pyranoxanthone, symphonin ( 1 ), 2-(3,3-dimethylallyl)-1,5- dihydroxy-6,7-dimethoxy-2”,2”-dimethylpyrano (5”,6”:3,4) xanthone, the known compounds guttiferone A, oleanolic acid and sitosterol were isolated from the methanol extract of the seeds of Symphonia globulifera (Guttiferae). The structural elucidation of the new compound was based mainly on spectroscopic analyses. The new xanthone showed antimicrobial activity against Staphylococcus aureus , Streptococcus feacalis , Klebsiella pneumonia and Escherichia coli . KEY WORDS: Symphonia globulifera , Seeds, Xanthone, Antimicrobial activity Bull. Chem. Soc. Ethiop. 2004 , 18(2), 175-180.

Search for Constituents with Neurotrophic Factor‐Potentiating Activity from the Medicinal Plants of Paraguay and Thailand

Abstract: 20 medicinal plants of Paraguay and 3 medicinal plants of Thailand were examined on nerve growth factor (NGF)-potentiating activities in PC12D cells. The trail results demonstrated that the methanol extracts of four plants, Verbena littoralis, Scoparia dulcis, Artemisia absinthium and Garcinia xanthochymus, markedly enhanced the neurite outgrowth induced by NGF from PC12D cells. Furthermore, utilizing the bioactivity-guided separation we successfully isolated 32, 4 and 5 constituents from V. littoralis, S. dulcis and G. xanthochymus, respectively, including nine iridoid and iridoid glucosides (1-9), two dihydrochalcone dimers (10 and 11), two flavonoids and three flavonoid glycosides (12-16), two sterols (17 and 18), ten triterpenoids (19-28), five xanthones (29-33), one naphthoquinone (34), one benzenepropanamide (35), four phenylethanoid glycosides (36-39) and two other compounds (40 and 41). Among which, 15 compounds (1-4, 10-11, 14-18, 29-31 and 34) were new natural products. The results of pharmacological trails verified that littoralisone (1), gelsemiol (5), 7a-hydroxysemperoside aglucone (6), verbenachalcone (10), littorachalcone (11), stigmast-5-ene 3beta,7alpha,22alpha-triol (18), ursolic acid (19), 3beta-hydroxyurs-11-en-28,13beta-olide (24), oleanolic acid (25), 2alpha,3beta-dihydroxyolean-12-en-28-oic acid (26), 1,4,5,6-tetrahydroxy-7,8-di(3-methylbut-2-enyl)xanthone (29), 1,2,6-trihydroxy-5-methoxy-7-(3-methylbut-2-enyl)xanthone (30), 1,3,5,6-tetrahydroxy-4,7,8-tri(3-methyl-2-butenyl)xanthone (31), 12b-hydroxy-des-D-garcigerrin A (32), garciniaxanthone E (33) and (4R)-4,9-dihydroxy-8-methoxy-alpha-lapachone (34) elicited marked enhancement of NGF-mediated neurite outgrowth in PC12D cells. These substances may contribute to the basic study and the medicinal development for the neurodegenerative disorder.

Isolation and crystal structure of xanthones from Swertia chirayita

Abstract: In order to study the relationship between biological and pharmacological activities with their structures, a series of tri- and tetra-oxygenated xanthones including 1-hydroxyl-2,3,4,7-tetramethoxy xanthone 1, 1-hydroxyl-2,3,4,5-tetramethoxyl xanthone 2, 1-hydroxyl-3,5-dimethoxyxanthone 3,1,8-dihydroxyl-3,5-dimethoxyl xanthone 4 and 1,5,8-trihydroxyl-3-methoxy xanthone 5 have been isolated from Swertia chirayita. Their structures were established on the basis of spectral and chemical evidences. The crystal structure of 5 was also investigated by single-crystal X-ray diffraction analysis. It crystallizes in the triclinic system, space group P1 with a = 7.1540(10), b = 7.520(2), c = 10.671(2) Angstrom, V = 562.7(2) Angstrom(3), alpha = 86.50(3), beta = 80.06(3), gamma = 85.00(3)degrees, Z = 2, D-c = 1.618 g/m(3), R = 0.0405, wR = 0.1028 and F(000) = 284. The molecular structure of 5 is nearly planar and four substituents are much closer to the plane. Compound 5 contains three intermolecular hydrogen bonds. A recent study shows that phenolic hydroxyls in xanthones are the main active groups capable of scavenging (OH)-O-. and O-2(.).

Studies on chemical constituents of Halenia elliptica guided by in vivo absorption and distribution of the constituents

Abstract: Aim To investigate the chemical constituents of the Tibetan herbal medicine Halenia elliptica by guidance of in vivo absorption and distribution of the constituents. Methods HPLC with a diode array detector (DAD) and HPLC-MS were used for detecting the constituents of extracts of Halenia elliptica and animal samples. Several kinds of column chromatography were used for the isolation and purification of the main in vivo absorbed and distributed compounds from the extract of Halenia elliptica . Results Six main components detected in the extracts of the animal samples were isolated from the ethanolic extract of Halenia elliptica . Conclusion After rats were treated with different extracts of Halenia elliptica , low polar components xanthone aglycon of Halenia elliptica were clearly observed in the extracts of liver, lipid, blood, hidney, heart and brain tissue of rats, while the polar components xanthone glycosides were detected in very small amounts in the animal samples. The xanthone glycosides can be decomposed into xanthone aglycons during the digestion, absorption and metabolism procedure. Therefore, the in vivo activity of the xanthone glycosides might be exhibited by their decomposed products. It is an accessibly valuable method to investigate chemical components of herbal medicines under the guidance by detecting in vivo absorption and distribution of chemical components of the herbal medicine extract.

New Phenolic Principles from Hypericum sampsonii.

Abstract: Using the anti-hepatitis B virus (HBV)-producing cell line MS-G2 in vitro cultural system-guided screening was performed, and two new benzophenones, 2,6-dihydroxy-4-[(E)-5-hydroxy-3,7-dimethylocta-2,7-dienyloxy]benzophenone (1) and 2,6-dihydroxy-4-[(E)-7-hydroxy-3,7-dimethylocta-2-enyloxy]benzophenone (2), a new xanthone, hyperxanthone (3), a new bisanthraquinone glycoside, R-(-)-skyrin-6-O-beta-D-xylopyranoside (4), and 2-caffeoyloxy-3-hydroxy-3-(3,4-dihydroxyphenyl)propyl alcohol (5), and 16 known compounds were isolated from the anti-HBV active fraction of the whole herbs of Hypericum sampsonii. Their structures were elucidated using spectroscopic methods, mainly 2D NMR and MS spectrometry. Circular dichroism was used to determine the stereochemistry of bisanthraquinone glycosides.

Topical anti-inflammatory activity of flavonoids and a new xanthone from Santolina insularis

Abstract: Bioactivity-guided fractionation of the methanol extract from the leaves of Santolina insularis led to the isolation of one new xanthone, (E)-3-{6-[(E)-3-hydroxy-3-oxo-1-propenyl]-9- oxo-9H-xanthen-2-yl}-2-propenoic acid, together with six known flavonoids: hispidulin, nepetin, cirsimaritin, rhamnocitrin, luteolin and luteolin 7-O-β-ᴅ-glucopyranoside. The structures were elucidated by means of 1D-, 2D-NMR spectroscopy and mass spectrometry. The topical anti-inflammatory activity of all isolated compounds and extracts was investigated employing the croton oil-induced dermatitis in mouse ear. The most active compound, luteolin, showed an ID50 of 0.3 μmol/cm2 and prevented ear oedema more effectively than an equimolar dose of indomethacin within 24 h.

A new xanthone from Polygala aureocauda Dunn

Abstract: AIM: To study the chemical constituents of Polygala aureocauda Dunn.. METHODS: Chemical compounds were isolated by column chromatography and their structures were determined mainly by spectroscopic means (UV, IR, MS, 1HNMR, 13CNMR, HMQC, HMBC). RESULTS: Three compounds were isolated and identified as 3-hydroxy-1,4-dimethoxyxanthone (I), 1, 7-dihydroxy-2, 3-methylendioxyxanthone (II), 7-hydroxy-1-methoxy-2, 3-methylendioxyxanthone (III). CONCLUSION: Compounds I-III were isolated from Polygala aureocauda Dunn. for the first time, whereas compound I is a new xanthone.

Isogentisin (1,3-di­hydroxy-7-methoxy­xanthone)

Abstract: The crystal structure of isogentisin, C14H10O5, a natural product isolated from Gentiana lutea, has been determined The phenolic ring system is essentially planar and the displacement of the methoxy substituent from the mean molecular plane is very small The structure is stabilized by a one-dimensional chain of intermolecular hydrogen bonds

Isopentenyl xanthone compounds and their use in the preparation of antitumor medicines

Abstract: The present invention belongs to the field of Chinese medicine technology, and is especially isopentenyl ketone compound from cudrania and its application in preparing antitumor medicine. The isopentenyl ketone compound of the present invention has relatively high antitumor activity and function of inhibiting vascularization and may be used in preparing antitumor medicine.

Determination of active constituents in fifteen species Swertia of genus by high performance liquid chromatography

Abstract: This paper deals with quantitave determination of three iridoid glycosides:swertiamarin,gentiopicroside and amarogentin,one flavonoidal glycoside:swertisin and five xanthone glycosides:mangiferin,swertianolin,7-O-[α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranosyl]-1,8-dihydroxy-3-methoxyxanthone),7-O-β-D-xylopy-ranosyl-1,8-dihydroxy-3-methoxyxanthone,and 3-O-β-D-glucopyranosyl-1,8-dihydroxy-5-methoxyxanth in fifteen Swertia species by means of HPLC.U-Bondapak C_(18) was used as the stationary phase,and water-methanol as the gradient solvent system.Analytical results were given.The similarities and diversities of these plants were compared and discussed.

A Xanthone-based Macrocyclic Receptor and Its Possible Applications

Abstract: – A macrocycle ( 2 ) based on xanthone units and diphenylethylenediamine is shown to present strong affinity for chloride ion; the extraction of sodium chloride from water to chloroform is possible in the presence of ( 2 ) and 18-crown-6 ether. Carboxylates also show strong affinities for ( 2 ) in MeOH, but no significant chiral recognition was detected for either naproxenate or ibuprofenate. Zwitterionic amino acids are also extracted from water to chloroform in the presence of 18-crown-6 ether. A modest degree of chiral discrimination was observed for phenylalanine, phenylglycine and t - leucine. INTRODUCTION Although receptors for cations can be found extensively throughout the literature, the study for anion receptors has been started more recently, but has already shown promising results. 1 Positively charged compounds are obvious recept ors for anions, ne vertheless neutral compounds capable to establish H-bonds, 2 like ureas, 3 can also be used to associate anions, and they offer many advantages. Cleft type receptors based on xanthones

Validation of a spectrophotometric method for quantification of xanthone in biodegradable nanoparticles

Abstract: guaranteeing the reliability of the results. Thus, a simple spectrophotometric method was validated according to USP25 and ICH guidelines for its specificity, linearity, accuracy and precision. The method was found to be specific for xanthone in the presence of nanoparticle excipients. The calibration curve was linear over the concentration range of 0.5 to 4.0 mg/mL (r > 0.999). Recovery of xanthone from nanoparticles ranged from 86.5 to 95.9%. Repeatability (intra-assay precision) and intermediate precision were found to be acceptable with relative standard deviations values (RSD) ranging from 0.3 to 3.0% and from 1.4 to 3.1%, respectively. The method was found to be suitable for the evaluation of xanthone content in nanoparticles of PLGA.

A New Naturally Occurring Xanthone Bearing Rare Oxygenation Pattern from Hoppea fastigiata

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.

Sampsoniones and xanthones of Hypericum sampsonii from Yunnan Province

Abstract: Object To study the chemical constituents of Hypericum sampsonii Hance from Yunnan Province Methods Cytotoxicity screening of extracts from wild and cultivated H sampsonii was carried out by L 1210 cell and KB cell Chemical constituents for wild H sampsonii were isolated by column chromatography The chemical structures were identified by physical and chemical properties and spectral data analysis Results Six compounds have been isolated and established as 1 benzoyl 3 (3 methyl 2 butenyl) 6, 6, 13, 13 tetramethyl 11 geranyl 5 lxatetracycol[7 3 1 0 3, 7 0 4, 11 ] tridecane 2, 12 dione (sampsonione A, Ⅰ); 1 benzoyl 5 (1 hydroxy isopropyl) 6, 6, 13, 13 tetramethyl 11 geranyl tetracycol [7 3 1 1 0 3, 7 ] tetradecane 2, 12, 14 trione (sampsonione F, Ⅱ); 3 (1 hydroxy 5 methyl 4 hexenyl) 6, 10 di (3 methyl 2 butyryl) 8 benzoyl 9, 9 dimethyl 4 oxatricycol [6 3 1 0 1, 5 ] 5 dodecene 7, 12 dione (sampsonione K, Ⅲ); 1,2 dihydro 3, 6, 8 trihydroxy 1, 1 bis (3 methyl but 2 enyl) xanthen 2, 9 dione (patulone, Ⅳ); 1, 7 dihydroxy 4 methoxy xanthone (Ⅴ) and 1, 3, 6, 7 tetrahydroxy 8 (3 methyl but 2 enyl) xanthone (Ⅵ) Conclusion Compounds Ⅳ-Ⅵ are first obtained from H sampsonii In addition, the fractions of chloroform extracting and ethyl acetate extracting possess anticancer activities by cytotoxicity tests

A New Regiospecific Preparation of Xanthones.

Abstract: 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.