Xanthones: Biosynthesis and Trafficking in Plants, Fungi and Lichens

Abstract

Xanthones are a class of secondary metabolites produced by plant organisms. They are characterized by a wide structural variety and numerous biological activities that make them valuable metabolites for use in the pharmaceutical field. This review shows the current knowledge of the xanthone biosynthetic pathway with a focus on the precursors and the enzymes involved, as well as on the cellular and organ localization of xanthones in plants. Xanthone biosynthesis in plants involves the shikimate and the acetate pathways which originate in plastids and endoplasmic reticulum, respectively. The pathway continues following three alternative routes, two phenylalanine-dependent and one phenylalanine-independent. All three routes lead to the biosynthesis of 2,3′,4,6-tetrahydroxybenzophenone, which is the central intermediate. Unlike plants, the xanthone core in fungi and lichens is wholly derived from polyketide. Although organs and tissues synthesizing and accumulating xanthones are known in plants, no information is yet available on their subcellular and cellular localization in fungi and lichens. This review highlights the studies published to date on xanthone biosynthesis and trafficking in plant organisms, from which it emerges that the mechanisms underlying their synthesis need to be further investigated in order to exploit them for application purposes.

Antibacterial Potential of Symmetrical Twin-Drug 3,6-Diaminoxanthones

“…Eighteen 3,6-disubstituted xanthones (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19), including fifteen aminated xanthones, were prepared from 3,6-dihydroxy-9H-xanthen-9-one (1). 3,6-Dihydroxy-9H-xanthen-9one (1) was obtained through a dehydrative cyclization of commercially available 2,2 ′ ,4,4 ′tetrahydroxybenzophenone-a straightforward methodology since no purification is needed to furnish 1 in quantitative yields, as previously reported elsewhere [21].…”

“…Xanthones are a class of organic compounds that occur naturally as secondary metabolites in various species of terrestrial and marine plants, fungi, and lichen [ 6 , 7 ]. These heterocyclic polyphenolic compounds with several naturally and synthetically occurring derivatives exhibited significant bactericidal and fungicidal properties against a variety of bacterial and fungal strains [ 8 , 9 ].…”

Secondary Metabolites, Biological Activities, and Industrial and Biotechnological Importance of Aspergillus sydowii

“…Xanthones are commonly found in lichen, fungi, plants, and bacteria [ 61 ]. In fungi, xanthones are mostly derived from acetyl-CoA through a series of polyketide synthase-catalyzed chemical transformations [ 62 ]. These metabolites were found to demonstrate diverse bioactivities.…”

Natural Compounds with Antimicrobial Activities in Oral Candida Infections during Head and Neck Radiotherapy

“…Hypericum perforatum L. (Hypericaceae) has been one of the most investigated medicinal plants due to its antidepressant activity, although it is studied for a broad range of other biological activities including wound-healing, anti-inflammatory, antibacterial, antifungal, and antiviral activities [108]. The roots of H. perforatum produce and accumulate xanthones, bioactive polyphenols, in small amounts, which increase in vitro-regenerated roots [109]. Xanthones showed high anti- Candida activity that increases with increasing concentration.…”