Xanthones as Potential Antioxidants

Abstract

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.

Structure–Activity Relationship and Prediction of the Electron‐Transfer Potential of the Xanthones Series

“…Polygala japonica ), the attention they have received is not the same. Whereas some studies have analyzed the structure–activity relationships of antioxidant flavonoids, there are none that have focused on the structure–activity relationships of antioxidant xanthones.…”

Comparative Study of 1,1‐Diphenyl‐2‐picryl‐hydrazyl Radical (DPPH•) Scavenging Capacity of the Antioxidant Xanthones Family

“…Xanthones and flavonoids are important sources of phenolic antioxidants. Sometimes, they co‐exist in the same medicinal plant (especially Chinese herbal medicine) ,. Their frameworks are quite different, however, in the flavonoid framework, there is a σ ‐bond between the B ring and A/C fused‐ring, and the rotation around this σ ‐bond can form different three‐dimensional configurations.…”

“…An in‐depth analysis suggested that the catechols in the xanthone family could be further divided into three types: 6,7‐catechol, 1,2‐catechol (or 7,8‐catechol), and 5,6‐catechol types ,,. For example, six xanthones ( 1, 2, 3, 4, 6 , and 15 ).…”

2,3-Diarylxanthones as Potential Inhibitors of Arachidonic Acid Metabolic Pathways

“…The pharmacological properties of both natural and synthetic xanthones (e.g., anti-inflammatory, antimalarial, antioxidant, and antitumour activities) are associated to different substituents in different positions of their main core [7][8][9][10][11][12]. Aryl groups linked to xanthones are scarce in natural sources, but several publications reporting their synthesis and/or biomedical potential have been highlighted in literature and reviewed in [13].…”