Toxyloxanthone B

[Chemical Constituents of Ethyl Acetate Fraction from Hypericum ascyron].[Pubmed:30080367]

Zhong Yao Cai. 2016 Feb;39(2):322-5.

Objective: To study the chemical consituents of Hypericum ascyron. Methods: The constituents were isolated and purified by chromatography on silica gel; the structure of the compound was determined by MS and NMR spectral analysis. Results: On the basis of spectroscopic analysis and comparison with the reported data, they were identified as hyperoside( 1),hypercalin B( 2),hypercalin C( 3),1,7-dihydroxyxanthone( 4),2,3-dimethoxyxanthone( 5),1-hydroxy-7-methoxyxanthone( 6),rutin( 7),kaempferol( 8),Toxyloxanthone B( 9),quercetin( 10),quercitrin( 11),beta-daucosterol( 12) and beta-sitosterol( 13). Conclusion: Compounds 2,3,6 and 9 are obtained from this plant for the first time.

Xanthones from roots, hairy roots and cell suspension cultures of selected Hypericum species and their antifungal activity against Candida albicans.[Pubmed:26194328]

Plant Cell Rep. 2015 Nov;34(11):1953-62.

KEY MESSAGE: Highest xanthone contents were found in Hypericum pulchrum and H. annulatum untransformed roots. The best anti- Candida activity was obtained for hairy roots extracts of H. tetrapterum clone 2 ATCC 15834. Extracts of root cultures, hairy roots and cell suspensions of selected Hypericum spp. were screened for the presence of xanthones and tested for their antifungal activity against Candida albicans strain ATCC 10231. At least one of the following xanthones, 5-methoxy-2-deprenylrheediaxanthone; 1,3,6,7-tetrahydroxyxanthone; 1,3,5,6-tetrahydroxyxanthone; paxanthone; kielcorin or mangiferin was identified in methanolic extracts of the untransformed root cultures. The highest total xanthone content, with five xanthones, was found in untransformed H. pulchrum and H. annulatum root cultures. Hairy roots and the controls of H. tetrapterum contained 1,7-dihydroxyxanthone, while hairy root cultures and the corresponding controls of H. tomentosum contained Toxyloxanthone B, 1,3,6,7- and 1,3,5,6-tetrahydroxyxanthone. Two xanthones, cadensin G and paxanthone, were identified in cell suspension cultures of H. perforatum. Their content increased about two-fold following elicitation with salicylic acid. The anti-Candida activity of the obtained extracts ranged from MIC 64 to >256 microg ml(-1). Among the extracts of Hypericum untransformed roots, the best antifungal activity was obtained for extracts of H. annulatum grown under CD conditions. Extracts of hairy roots clones A4 and 7 ATCC15834 of H. tomentosum and clone 2 ATCC15834 of H. tetrapterum displayed inhibition of 90% of Candida growth with 256 mug ml(-1). Extracts from chitosan-elicitated cells did not show antifungal activity.

Phenolic constituents from the leaves of Cratoxylum formosum ssp. pruniflorum.[Pubmed:24534445]

Fitoterapia. 2014 Apr;94:114-9.

One (formosumone A, 1) new and fifteen (2-16) known phenolic compounds were isolated from the leaves of Cratoxylum formosum ssp. pruniflorumm, a substitute for the popular bitter nail tea ("Kuding Tea") generally used in Southeast Asia. Their structures were determined by extensive spectroscopic analysis and by comparison with literature data. Compound 1 possesses a rare scaffold of a flavanone coupled with a phloroglucinol moiety, representing the first example of such a scaffold from the Clusiaceae family. Among the isolates, Toxyloxanthone B (11) and vismione D (12) were found to show remarkable anti-neuroinflammatory effects by inhibiting nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated murine BV-2 microglial cells. Additionally, Toxyloxanthone B (11) exhibited significant neuroprotective effect against beta-amyloid(25-35) (Abeta(25-35))-induced cell viability decrease in SH-SY5Y neuroblastoma cells.