Chemistry and biological activities of naturally occurring C-glycosylxanthones

Abstract

The xanthones represent an important and widely spread class of specialized metabolites in the plant kingdom, fungi, and lichens . Their aromatic and highly oxygenated structures owe them the ability to undergo a series of chemical reactions to form an important number of derivatives as well as to exert a large scale of excellent activities that particularly increased their interest for several researchers. Amongst the reactions observed on their basic nucleus, C-glycosylation leads to the formation of C-glycosylxanthones, a rare subclass of xanthones encountered in nature. Until July 2023, the literature survey on chemical and pharmacological investigations of medicinal plants indicated that a total of 41 distinct natural C-glycosylxanthones have been isolated from 31 plant species belonging to 10 families. Mangiferin ( 1 ) was the most reported one and the most biologically screened. Antioxidant activity was the most performed test on isolated compounds, while some strong and good anti-inflammatory, antiplasmodial, and α-glucosidase inhibitory activities have been also reported in the literature for some C-glycosylxanthones. This paper is a mini-review summarizing the occurrence, chemistry, and biological activities of C-glycosylxanthones. The writing of this paper has been done using the literature collected from online libraries including SciFinder, PubMed, Web of Science, and Google Scholar using keywords xanthone, glycosyl, C-glycosylxanthone, without language restriction. This review represents therefore the easiest access to the information on C-glycosylxanthones for researchers intending to also continue the research investigations on this topic. • This review summarizes the occurrence, the chemistry and pharmacology of C-glycoxanthones. • Forty-one naturally occurring C-glycosylxanthones have been identified and reported in the literature so far. • The distribution, classification and biosynthesis of C-glycosylxanthones are discussed. • The pharmacology of the C-glycosylxanthones is discussed.