Xanthones as potential antioxidants.

Xanthones (dibenzo-γ-pyrones) constitutes an important class of oxygenated heterocycles and occur as secondary metabolites in plants and microorganisms. They are known for various biological activities such as antioxidant, monoamine oxidase inhibitor, antihypertensive, hepatoprotective, antithrombotic, antifungal and anticancer. The tricyclic scaffold as well as the nature and/or position of the substituents present on it play an important role in displaying various biological activities. The unique structural scaffold and medicinal importance of xanthones have therefore attracted many Scientists in the past, to isolate or synthesize xanthones or their analogs as potential drug candidates. It would not be wrong to call them as close cousins to the polyphenol family that are known to possess strong antioxidant effects on the nervous system. The main two sources of xanthones are: Isolation from natural resources or synthesis. Though few reviews have been published in the past, mainly focusing on the anticancer activities of xanthone derivatives, but there is not a single review which is based on their antioxidant activities. We therefore have made efforts to briefly summarize natural and synthetic xanthones possessing antioxidant activity in this review.