Xanthones biological activities

Dall Acqua F, see Gambari R (2007) 9 265-276 Daneshtalab M (2006) Novel Synthetic Antibacterial Agents. 2 153-206 Demirkiran O (2007) Xanthones in Hypericum Synthesis and Biological Activities. 9 139-178... 

Xanthones in Hypericum Synthesis and Biological Activities O. Demirkiran... 

The biological activity of flavonoids has attracted much interest in the part twenty years and a few compounds of this class have been shown to have AChEI effects. The flavanone naringenin (74) from Citrus junos (Rutaceae) ameliorated scopolamine-induced amnesia in mice, which may be related to an antiAChE effect, since naringenin was shown to inhibit AChE in vitro dose dependently. A recent theoretical study has shown that flavonoids and xanthones exhibit polyvalent effects such as antioxidant, amyloid reduction and cholinesterase inhibition, which made them interesting candidates for further studies. 

Many constituents with potential biological activity have been extracted from the flowers and leaves, the parts of the plant used for medicinal purposes. These include naphthodianthrones, flavonoids, phlorogluci-nols, and xanthones. Hypericin, one of the naphthodianthrones, has traditionally been considered the main active ingredient, but it is not known whether this is the compound with antidepressant activity. Recent data suggest that a component called hyperforin may be more important than hypericin for the antidepressant activity. 

Biological Activities of Xanthones Isolated from Hypericum Species. .. 169... 

Abstract There has been an increasing interest in the genus Hypericum, because it is a source of a variety of compounds with different biological activities. Xanthones are... 

The aim of this chapter is not only to provide a review of the distribution of xanthones in Hypericum genus, but also to cover some more specific aspects such as biosynthesis, chemotaxonomic significance, biological activities, and synthesis. 

In this chapter, as well as the methods currently used for the isolation, separation, and structure elucidation of xanthones, their biosynthesis, synthesis, and importance as therapeutic agents was also discussed. The use of recently developed chromatographic techniques will provide characterization of these compounds and lead to the discovery of new xanthones. There are still many xanthones waiting to be discovered and evaluated by researchers for their many more biological activities. 

Clusiaceae (Guttiferae) is a family almost exclusively tropical in distribution and comprises about 40 genera and 1200 species most of which are woody [1], Extensive phytochemical studies have shown Clusiaceae to be a rich source of secondary metabolites including xanthones, triterpenoids, flavonoids, lactones and organic acids. In addition plants of this family produce a series of oxidized and polyisoprenylated benzophenones (PBDs), some of which are structurally complex and biologically active. 

Historically, reviews of benzophenones were included as small sections with the biogenetically related xanthones. Previous reviews include Bennett and Lee [1] who discussed the distribution and isolation of 20 benzophenones included in a review focused on xanthones. They also discussed the biosynthetic relationships between xanthones and benzophenones. Kumar and Baslas [2] summarized the chemical composition, medical importance, and biologically active benzophenones, biflavonoids, and xanthones isolated from Garcinia species. Two reviews by Waterman focused on the chemotaxonomic significance of benzophenones, along with biflavonoids and xanthones, of ten African Garcinia species [3,4], Locksley and Murray [5] discussed the distribution of thirteen benzophenones in higher plants and Sultanbawa [6] included five benzophenones in a review on xanthonoids from tropical plants. Sultanbawa also discussed the biosynthesis of benzophenones and xanthones. Erdelmeier et al. [7] discussed 20 polyprenylated benzophenones in a chapter on the various properties of St. John s Wort Hypericum perforatum). 

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