Antioxidant Nature Adds Further Therapeutic Value: An Updated Review on Natural Xanthones and Their Glycosides

Abstract

Plants have so much to offer as far as the discovery of new bioactive molecules is concerned. Among the several classes of phytochemicals, xanthones offer greater structural diversity and pharmacological value. They are variable but definitely antioxidant in nature. Thus they are attractive targets for natural product and medicinal chemists. Xanthones and their glycosides possess broad spectrum interesting biological activities, such as cytotoxic, anti-inflammatory, antioxidant, anti-bacterial, neuroprotective, anti-HIV, enzyme inhibition, and hypoglycemic. The radical scavenging ability of these molecules accounts for most of their added therapeutic values. This paper intended to serve as a guide for future endeavors in quest for these molecules. Structure-Activity Relationship (SAR) and mechanism of action is given for better understanding of their role as pharmacological agents. The most recent advances in the isolation of bioactive xanthones and their glycosides were presented here. This paper will assist in directed approaches towards the discovery of analogues of xanthones. Keywords: Xanthones, Xanthone glycosides, Antioxidant, Radical scavenging, Xanthone dimers, Xanthone trimers