Showing papers on "Xanthone published in 1998"
TL;DR: Flow cytometric histograms revealed a specific pattern; that is, lawsone and juglone in the naphthaquinone group and alizarin and 1,8-dihydroxy-anthraquin one in the anthraquinones group blocked mainly the S phase of the cell cycle.
Abstract: Quinones were studied for their growth inhibitory effect on cultured malignant cells. HCT-15 cells derived from human colon carcinoma were used for these experiments. Quinones used were arbutin in the benzoquinone group, juglone and lawsone in the naphthaquinone group, alizarin, emodin, 1,8-dihydroxyanthraquinone, and anthraquinone in the anthraquinone group, and xanthone. Cultured cells were incubated with various concentrations of the quinones for four days in a 5% C02 incubator, after which cell numbers were counted and significance of differences was analyzed by Student's t test. Anthraquinones and naphthaquinones used in these experiments were more effective than the monocyclic quinone. The 50% suppression dose was less than 12.5 μg/ml for them. The number of OH groups seemed to play an important role in the degree of the cell growth inhibition: anthraquinones with 2 or 3 OH groups were more effective than those with no OH group like, 9,10-dioxoanthracene and xanthone. In fact, anthraquinones with no...
114 citations
TL;DR: From the aerial part of Hypericum japonicum, one new xanthone glycoside, 1,5-dihydroxyxanthone-6-O-beta-D-glucoside, and one novel dimer xanth one, bijaponicaxanthone, were isolated together with the four known xanthones.
77 citations
TL;DR: In this paper, the dichloromethane extracts of Kielmeyera coriacea leaves and stems were analyzed by high performance liquid chromatography coupled with a photodiode array detector (LC-UV) and thermospray liquid-chromatography-mass spectrometry (TSP/LC-MS) revealed the presence of several xanthones.
68 citations
31 citations
TL;DR: A new xanthone was isolated from the stem bark of Garcinia atroviridis and its structure elucidation and unambiguous NMR spectral assignment were achieved by the aid of the combination of 1D and 2D NMR techniques.
31 citations
TL;DR: As a chemical constituent of Garcinia cambogia, a new xanthone, garbogiol, was isolated from the root; a known Xanthone (rheediaxanthone A) and two known benzophenones (garcinol and isogarcinol) were obtained from the bark.
30 citations
TL;DR: 1,2-Dimethoxy-5-hydroxyxanthone was isolated from the twigs of Mammea siamensis, in addition to six known xanthones, and structures for these compounds were deduced from their spectral data.
28 citations
TL;DR: One new prenylated xanthon, ananixanthone, was isolated from the bark of Symphonia globulifera by NMR spectroscopy including 2D techniques.
23 citations
TL;DR: In this article, a novel antifungal agent, Sch 56036 (1 ), was isolated from the fermentation culture broth of an Actinoplanes sp. Structure elucidation of 1 was accomplished by the analysis of spectroscopic data.
23 citations
TL;DR: A new benzophenone derivative and a new xanthone have been isolated from the wood of Garcinia subelliptica by analysis of the spectroscopic data and comparison of the NMR data with those of the compounds previously reported.
17 citations
Journal Article•
TL;DR: In this article, the physicochemical properties of alkanolamine derivatives of xanthone were described and synthesized by of the reaction of an appropriate aminoalcohol with corresponding 2-bromomethylxanthones.
Abstract: Synthesis and physicochemical properties of alkanolamine derivatives of xanthone are described. Alkanolamines were synthesized by of the reaction of an appropriate aminoalcohol with corresponding 2-bromomethylxanthones. The obtained compounds 1-13 were evaluated for anticonvulsant activity in the maximal electroshock seizure (MES) and subcutaneous pentylenetetrazole seizure threshold (scMet) assays and for neurotoxicity (TOX). Several alkanolamines were found to be active in both the anticonvulsant tests. Most interesting were the 2-amino-1-propanol-, 1-amino-2-propanol- or 1-amino-2-butanol derivatives of 6-methoxy- or 6-chloroxanthone, which displayed anti MES activity with a protective index (TD50/ED50) in the range 2.21-5.84 corresponding with that for phenytoin, carbamazepine and valproate.
TL;DR: Most interesting were the anticonvulsant results of the appropriate 2-amino- or 2-N-methylamino-1-butanol derivatives of 7-chloroxanthone 8-11, which displayed anti-MES activity with a protective index in the range 2.84-3.62 corresponding with that for phenytoin, carbamazepine and valproate.
Abstract: A series of alkanolamides and alkanoamines derivatives of xanthone were prepared and evaluated for antiepileptic activity in the maximal electroshock seizure (MES) and subcutaneous pentylenetetrazol seizure threshold (ScMet) assays and for neurotoxicity (TOX). Several analogues from the appropriate alkanolamines were found to be active in both the anticonvulsant tests. Most interesting were the anticonvulsant results of the appropriate 2-amino- or 2-N-methylamino-1-butanol derivatives of 7-chloroxanthone 8-11, which displayed anti-MES activity with a protective index (TD50/ED50) in the range 2.84-3.62 for 8-11 corresponding with that for phenytoin, carbamazepine and valproate.
Journal Article•
TL;DR: A series of alkanolamides and alkanoamines derivatives of xanthone were prepared and evaluated for antiepileptic activity in the maximal electroshock seizure (MES) and subcutaneous pentylenetetrazol seizure threshold (ScMet) assays and for neurotoxicity (TOX) as mentioned in this paper.
Abstract: A series of alkanolamides and alkanoamines derivatives of xanthone were prepared and evaluated for antiepileptic activity in the maximal electroshock seizure (MES) and subcutaneous pentylenetetrazol seizure threshold (ScMet) assays and for neurotoxicity (TOX). Several analogues from the appropriate alkanolamines were found to be active in both the anticonvulsant tests. Most interesting were the anticonvulsant results of the appropriate 2-amino- or 2-N-methylamino-1-butanol derivatives of 7-chloroxanthone 8-11, which displayed anti-MES activity with a protective index (TD50/ED50) in the range 2.84-3.62 for 8-11 corresponding with that for phenytoin, carbamazepine and valproate.
TL;DR: CIDEP spectra from free radicals produced by the photolysis of xanthone (Xn) in 2-propanol were investigated with FT-EPR.
Abstract: CIDEP spectra from free radicals produced by the photolysis of xanthone (Xn) in 2-propanol were investigated with FT-EPR The spectra were assigned to the 2-hydroxypropan-2-yl (2HP) and xanthone ketyl (XnH) radicals In pure 2-propanol and 2-propanol containing 10% H2O, the spectra display low field emission/high field absorption with net emission (E*/A) type polarization The observed CIDEP pattern is mainly due to the S−T0 radical pair mechanism (RPM) with minor contributions from the triplet mechanism (TM) and radical triplet pair mechanism (RTPM) Upon addition of HCl, the polarization changes to net absorption The rise time of the absorptive signals is determined by the response time of the spectrometer (∼3 × 10-8 s) Transient optical absorption measurements show that the triplet state of xanthone (3Xn*) is quenched by HCl, and the change in spin polarization produced by HCl addition is attributed to this quenching process The dependence of the CIDEP pattern and triplet xanthone lifetime on HCl co
TL;DR: In this article, four xanthone glycosides were isolated from the n-butanol fraction of ethanolic extract of Swertia calycina, and identified using melting points and spectroscopic methods.
Abstract: Four xanthone glycosides were isolated from the n-butanol fraction of ethanolic extract of Swertia calycina Franch., and identified using melting points and spectroscopic methods as 1,3,7,8-tetrahydroxyxanthone-8-O-β-D-glucopyranoside, 1,3,7,8-tetrahydroxyxanthone-1-O-β-D-glucopyranoside, swertianolin and mangiferin.
Mangiferin was tested for potential pharmacological activity and was found to have a significant hepatoprotective effect against liver damage induced by acetaminophen, carbon tetrachloride and D-GalN in rats.
TL;DR: Three antifungal xanthones have been isolated from the dichloromethane root extract of Marila laxiflora (Guttiferae) and their structures were established by spectrometric (UV, EI mass spectrometry, 1 H and 13 C nmr) and chemical methods as discussed by the authors.
Abstract: Three antifungal xanthones have been isolated from the dichloromethane root extract of Marila laxiflora (Guttiferae). Their structures were established by spectrometric (UV, EI mass spectrometry, 1 H and 13 C nmr) and chemical methods. In addition, other compounds were isolated from the methanol extract: a fourth xanthone, rhamnetin, betulinic acid, and a derivative of benzoic acid.
TL;DR: A number of xanthone derivatives bearing the basic chain of naftifine and butenafine antimycotics in 1, 2, 3, and 4 nuclear positions show significant activity against, Cryptococcus neoformans and the regioisomer 4d.
Abstract: A number of xanthone derivatives bearing the basic chain of naftifine and butenafine antimycotics in 1, 2, 3, and 4 nuclear positions are described. The in vitro antifungal activity against representative strains of molds and yeasts is reported. Only butenafine xanthone analogues show significant activity against Cryptococcus neoformans, in particular the regioisomer 4d (1.5 micrograms/ml).
Journal Article•
TL;DR: In this article, a new xanthone was identified from the chloroform and ethyl acetate fractions of Halenia corniculata (Gentianaceae).
Abstract: A new xanthone, a new xanthone glycoside and a known xanthone have been isolated from the chloroform and ethyl acetate fractions of Halenia corniculata (Gentianaceae). They were identified as 1,3-dihydroxy-2,4,5,7-tetramethoxyxanthone, 1-hydroxy-2,7-dimethoxy-3-O-β-D-glucopyranosylxanthone and 1,2,3-trihydroxy-5-methoxyxanthone. 1,3-Dihydroxy-2,4,5,7-tetramethoxyxanthon is a revised structure from 1,6-dihydroxy-2,3,4,8-tetramethoxyxanthone reported by our previous paper.
TL;DR: A new xanthone, clusone, isolated from the fresh flowers of an Amazonian medicinal plant, Clusia insignis, has been characterized as 1-3,4,5,6-pentamethoxy 9H-xanthen-9-one by means of spectroscopic evidence.
TL;DR: In this article, apetalinone A-C and tomentonone were isolated from the roots of Calophyllum apetalum, which indicated a new biosynthetic pathway including Claisen rearrangement and Diels-Alder reaction.
Abstract: Three new xanthonoids, apetalinones A-C, were isolated from the roots of Calophyllum apetalum, as well as the known compounds, calozeyloxanthone and zeyloxanthonone. The stem bark of this species yielded a new xanthonoid, apetalinone D, and another known xanthonoid, tomentonone. Five known xanthones (3,8-dihydroxy-1,2-dimethoxy-, 1,3-dihydroxy-2,5-dimethoxy-, 1,5-dihydroxy-, 1,3,5-trihydroxy-2-methoxy- and 1,3,5-trihydroxyxanthone) and two flavonoids ((−)-epiafzelechin and (−)-epicatechin) were also characterized as constituents in the stem wood. Among them, apetalinone A was a novel xanthone with 1,1-dimethylallyl ether moiety, which indicated a new biosynthetic pathway including Claisen rearrangement and Diels-Alder reaction.
Patent•
04 Aug 1998
TL;DR: In this paper, a Na/H exchange transport-based inhibitor was obtained by including an isoflavone and a xanthone as an active ingredient and a dose is 1-1,000mg calculated as the compound of the formula per adult.
Abstract: PROBLEM TO BE SOLVED: To obtain a Na /H exchange transport-based inhibitor high in activity and slight in adverse effects by including an isoflavone and a xanthone. SOLUTION: This agent comprises an isoflavone of formula I (A is a group of formula II, a group of formula III, etc.; R is OH; R and R are each H or prenyl; R and R are bonded to form a ring, a group of formula IV in which OH is acylated) or a xanthone as an active ingredient. Erythrinin B, euchrenone b10 or 1,3,5-trihydroxy-4-(3-methylbut-2-enyl)-xanthen-9-one may be cited as the compound of formula I. The compound is obtained by chemical synthesis or extraction from a plant for crude medicine and isolation. A dose is 1-1,000mg calculated as the compound of the formula per adult. The agent is effective for preventing and treating especially hypertension, arrhythmia, angina pectoris, hypercardia, diabetic, organopathy and cerebral ischemia disorder caused by ischemia and ischemia reperfusion.