Topic
Xanthone
About: Xanthone is a research topic. Over the lifetime, 1639 publications have been published within this topic receiving 25870 citations. The topic is also known as: 9-oxo-xanthene & Diphenyline ketone oxide.
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TL;DR: In this article, the orientation and reactions of 1-acetyl-2-hydroxyxanthone (I; R 1 Ac, R 2 R 3 ǫ H) leading to the synthesis of angular furanoxanthones (III; R Me) and pyronoxanthone of the type (V) are described.
13 citations
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TL;DR: In this paper, Salicylic acid and C-methylphloroglucinol gave the already known 1,3-dihydroxy-2-methylxanthone (1) along with two new compounds: 1, 3-dhedroxy-4-methyl xanthone(2) and a second one tentatively presented as being 1.3dhedioxymethyl-2.4-(2-hydroxybenzoyl)xanthones (3).
Abstract: Condensation of salicylic acid and C-methylphloroglucinol gave the already known 1,3-dihydroxy-2-methylxanthone (1) along with two new compounds: 1,3-dihydroxy-4-methylxanthone (2) and a second one tentatively presented as being 1,3-dihydroxy-2-methyl-4-(2-hydroxybenzoyl)xanthone (3). The UV., IR., NMR, and mass spectra for the two first compounds are reported and their structures discussed on the basis of δ-values for H(2), H(4), CH3(4) and CH3(2). The UV. and IR. spectra for the third compound are reported too.
12 citations
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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.
12 citations
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TL;DR: Ultrasound assisted extraction (UAE) was employed to extract xanthone from dried M. pericarp and compared with soxhlet extraction and maceration and the optimum conditions from Box-Behnken design were determined to be temperature 33°C, amplitude 75 and 80% ethanol.
Abstract: Mangosteen pericarp has been used for long time as traditional medicine. One of main active ingredient in M. pericarp is xanthone. Xanthone has remarkable effects on cardiovascular health, antiviral and anti-inflammatory. Ultrasonic Assisted Extraction (UAE) was employed to extract xanthone from dried M. pericarp and compared with soxhlet extraction and maceration. The UAE was applied by various temperature (33, 45 and 55°C), amplitude (25, 50 and 75%) and solvent (0, 50 and 95% ethanol) for 1 h extraction time. The conditions for the highest xanthone recovery were determined at temperature 33°C, and 50% ethanol at 50% amplitude, resulting 0.16 mg/g of dried M. pericarp. The Box-Behnken design was applied to investigate the optimum condition of UAE. The optimum conditions from Box-Behnken design to obtain the highest xanthone recovery were determined to be temperature 33°C, amplitude 75 and 80% ethanol. The results presented that for UAE in 0.5 h, soxhlet extraction in 2 h and maceration in 2 h, the extracted xanthones were 0.1760, 0.1221 and 0.0565 mg/g of dried M. pericarp respectively.
Key word: Ultrasound assisted extraction (UAE), Mangosteen pericarp, xanthone, maceration.
12 citations
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TL;DR: In this paper, the chemical structure and relative configuration of a new triterpene 1,3-dioxo-16α-hydroxyfriedelane (15) were established through 1H and 13C NMR including 2D experiments (HMBC, HMQC, COSY and NOESY).
Abstract: The chemical investigation of Salacia elliptica allowed to the isolation of 20 constituents: two polyols, one xanthone, a mixture of long chain hydrocarbons, one carboxylic acid, one polymer, two steroidal compounds, one aromatic ester and eleven pentacyclic triterpenes. These triterpenes include 3β-stearyloxy-oleanane, 3β-stearyloxy-ursane, one seco-friedelane, and eight compounds of the friedelane serie. The chemical structure and the relative configuration of a new triterpene 1,3-dioxo-16α-hydroxyfriedelane (15) were established through 1H and 13C NMR including 2D experiments (HMBC, HMQC, COSY and NOESY) and herein reported for the first time.
12 citations