Many fungi, lichens, and bacteria produce xanthones (derivatives of 9H-xanthen-9-one, “xanthone” from the Greek “xanthos”, for “yellow”) as secondary metabolites. Xanthones are typically polysubstituted and occur as either fully aromatized, dihydro-, tetrahydro-, or, more rarely, hexahydro-derivatives. This family of compounds appeals to medicinal chemists because of their pronounced biological activity within a notably broad spectrum of disease states, a result of their interaction with a correspondingly diverse range of target biomolecules. This has led to the description of xanthones as “privileged structures”.(1) Historically, the total synthesis of the natural products has mostly been limited to fully aromatized targets. Syntheses of the more challenging partially saturated xanthones have less frequently been reported, although the development in recent times of novel and reliable methods for the construction of the (polysubstituted) unsaturated xanthone core holds promise for future endeavors. In particular, the fascinating structural and biological properties of xanthone dimers and heterodimers may excite the synthetic or natural product chemist.

Xanthones from Fungi, Lichens, and Bacteria: The Natural Products and Their Synthesis

Xanthones from fungi, lichens, and bacteria : the natural products and their synthesis

Nano silver particle synthesis using Swertia paniculata herbal extract and its antimicrobial activity

Medicinal, biological and phytochemical properties of Gentiana species

Highly sensitive and selective pre-column derivatization high-performance liquid chromatography approach for rapid determination of triterpenes oleanolic and ursolic acids and application to Swertia species: Optimization of triterpenic acids extraction and pre-column derivatization using response surface methodology

A compilation of the constituents isolated from Swertia species covering the literature up to December 2003 is presented. The botanical classification and ethno-pharmacology of Swertia plants, as well as the biological activities and pharmacological applications of both distinct phytochemicals and medicinally acitve plant materials (formulations, extracts, etc.) are discussed in detail.

Shamal Saha

Papers

Swertia (Gentianaceae): chemical and pharmacological aspects.