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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01 Jan 1991
TL;DR: The isolation and structure elucidation of a new xanthone, 1,7-dihydroxy-3,5-dimethoxyxanthone from the aerial parts and roots of Hoppea fastigiata is reported.
Abstract: The petroleum ether (60-80°) extract of the whole plants (aerial parts and roots) of Hoppea fastigiata yielded a new xanthone, 1,7-dihydroxy-3,5-dimethoxyxanthone.Hoppeu fustigiutu Clarke (Gentianaceae) (1) was collected from Santiniketan and identified. The plants are used by tribes for a variety of ailments and apparently have not been investigated previously. In continuation of our studies on plant pigments (2-6), we now report the isolation and structure elucidation of a new xanthone, 1,7-dihydroxy-3,5-dimethoxyxanthone from the aerial parts and roots of this species. This substitution pattern is extremely uncommon in xanthones and is reported previously by Rama Rao et al. (7).
5 citations
TL;DR: In this article, the synthesis of 1-hydroxy-3,6,7-trimethoxy-2,8-bis-(2-oxoethyl)xanthone, first obtained from ozonolysis of dimethylmangostin, is described.
Abstract: The synthesis of the dialdehyde 1-hydroxy-3,6,7-trimethoxy-2,8-bis-(2-oxoethyl)xanthone, first obtained from ozonolysis of dimethylmangostin, is described. Xanthone formation by cyclisation of a benzophenone intermediate is followed by selective demethylations, allylation, and Claisen rearrangement. Oxidative cleavage of the allyl side chains in 2,8-diallyl-1,3,6,7-tetramethoxyxanthone, followed by demethylation with boron trichloride, gave the required dialdehyde (5). Some 13C n.m.r. spectra of xanthones are discussed.
5 citations
TL;DR: Study on NPC- TW01 cell cycle distribution revealed that compound 13 inhibited proliferation of NPC-TW01 by the alteration of cell division and the accumulation of cells in G0/G1 phase.
Abstract: Certain amide-containing anthraquinone, xanthone, and carbazole derivatives have been synthesized and evaluated in vitro for their antiproliferative activities against a panel of human cancer cell lines including nasopharyngeal carcinoma (NPC-TW01), lung carcinoma (NCI-H661), and leukemia (Jurkat). Among them, 2-(9,10-dioxo-9,10-dihydroanthracen-2-yloxy)-N-(naphthalen-2-yl)acetamide (13) was the most active against NPC-TW01 with an IC50 value of 2.62 µM while its xanthone and dibenzofuran counterparts, 14 and 15, were inactive with an IC50 value of 16.10 and 11.09 µM, respectively. Studies on NPC-TW01 cell cycle distribution revealed that compound 13 inhibited proliferation of NPC-TW01 by the alteration of cell division and the accumulation of cells in G0/G1 phase.
5 citations
TL;DR: A new xanthone, 1,5-dihydroxy-2,3,4-trimethoxyxanthone-1-O-gentiobioside, together with 15 known compounds, was isolated from an ethanolic extract of Halenia elliptica D. Don by spectroscopic methods.
5 citations
TL;DR: It is shown that DHXD is a cytosolic enzyme, induced by growth on xanthone and maximally expressed during the stationary phase of growth, and the activity of this extradiol meta-fission dioxygenase is characterized in terms of its basic enzymological properties.
Abstract: Bacterial extradiol ring-fission dioxygenases play a critical role in the transformation of multiring aromatic compounds to more readily biodegradable aromatic or aliphatic intermediates. Arthrobacter sp. strain GFB100 utilizes an extradiol meta-fission dioxygenase, 3,4-dihydroxyxanthone dioxygenase (DHXD), in the catabolism of the three-ring oxygen heterocyclic compound xanthone. In this paper, we show that DHXD is a cytosolic enzyme, induced by growth on xanthone and maximally expressed during the stationary phase of growth. In addition, we characterize the DHXD activity in terms of its basic enzymological properties. 1,10-Phenanthroline and H2O2 treatments eliminated DHXD activity, indicating that the enzyme required Fe2+ ions for activity. Other divalent cations were either inhibitory or had no effect on activity. DHXD had a temperature optimum of 30 degrees C and a pH optimum of 7.0. DHXD followed typical saturation kinetics and had an apparent Km of 10 microM for 3,4-dihydroxyxanthone. The dye celestine blue served as a noncompetitive DHXD inhibitor (Ki, 5 microM). Several other structural analogs served neither as substrates nor inhibitors. DHXD was thermally labile at temperatures above 40 degrees C. The half-life for thermal DHXD inactivation was 5 min at 40 degrees C. DHXD activity was completely stable through one freeze-thaw cycle, and about 80% of the DHXD activity remained after 2 days of incubation at 0 degree C. The apparent tight binding of the Fe2+ cofactor to DHXD may be a factor contributing to the stability of this extradiol dioxygenase when it is stored.
5 citations