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 ionic and radical photobehaviour has been observed for 2-halogeno-1,1-diphenylethylenes, and the three major products being diphenylacetylene, 1, 1-Diphenylthylene, and 1,1,4,4-tetraphenylbutadiene.
Abstract: Competing ionic and radical photobehaviour has been observed for 2-halogeno-1,1-diphenylethylenes. Irradiation of 2-fluoro-1,1-diphenylethylene in cyclohexane or ether afforded cis- and trans-fluorostilbene. Irradiation of the chloro, bromo, or iodo analogues gave a complex mixture of up to eight products, the three major products being diphenylacetylene, 1,1-diphenylethylene, and 1,1,4,4-tetraphenylbutadiene. The product distribution proved to depend on the halogen and on the solvent. Benzophenone or xanthone sensitised irradiation of 2-fluoro-1,1-diphenylethylene in cyclohexane gave 1-cyclohexyl-1-fluoro-2,2-diphenylethane, while irradiation of 2-chloro 1,1-diphenylethylene gave 2-cyclohexyl-1,1-diphenylethylene.
6 citations
Journal Article•
TL;DR: Compounds VIII and IX were isolated from Swertia davidi Franch, for the first time, whereas compound X is a new xanthone, named daviditin B with antioxygenated activity in vitro.
Abstract: AIM To study the active constituents of Swertia davidi Franch. METHODS Chemical components were isolated by column chromatography and their structures were established mainly by spectroscopic means (UV, IR, NMR, 2D-NMR, MS). RESULTS Three substances were identified as 2,5-dimethoxyl-1, 4-dicarboxyl benzene (VIII), 1,5,8-trihydroxyl-3,4-dimethoxyl xanthone (IX) and 1,8-dihydroxyl-3-(3'-hydroxyl-butoxy) xanthone (X). CONCLUSION Compounds VIII and IX were isolated from Swertia davidi Franch, for the first time, whereas compound X is a new xanthone, named daviditin B with antioxygenated activity in vitro.
6 citations
TL;DR: This study revealed that the presence of the C-4 prenyl residue attached to the xanthone core is correlated with the significant PDE5 inhibitory activity.
Abstract: Five flavonoids, one isoflavone and five xanthones were isolated from Anaxagorea luzonensis. Of these eleven isolated compounds, 1,3,5-trihydroxy-4-prenylxanthone (3) was a relatively potent inhibitor of phosphodiesterase type 5 (PDE5), with an IC50 value of 3.0 μM. This is the first report showing that natural xanthones can exhibit promising PDE5 inhibitory activity. Moreover, this study revealed that the presence of the C-4 prenyl residue attached to the xanthone core is correlated with the significant PDE5 inhibitory activity.
6 citations
6 citations
6 citations