A review on xanthone derivatives with antiinflammatory effects and their structure–activity relationship

Abstract Inflammation is a response to the immune system to protect our body from the infection of foreign organisms, such as bacteria and viruses. However, uncontrolled acute inflammation may lead to a variety of chronic inflammations, which may cause life-threatening hypersensitivity reactions and progressive organ damage, such as cancer, heart, and neurodegenerative diseases. Nonsteroidal antiinflammatory drugs (NSAIDs) are effective but possess adverse effects at therapeutic doses, including stomach ulcers, heart attack, and stroke. Thus, there is an urgent need to look for alternative antiinflammatory drugs. Xanthone, a secondary metabolite from natural products, is a potential lead compound for antiinflammatory drugs. The basic skeleton of xanthone is made up of two aromatic rings that fused through a carbonyl group and an oxygen atom. The biological activities of xanthones are associated with their tricyclic scaffold and varied depending on the nature and/or position of their substituent groups. This compound is well-known for a wide range of biological activities, including anticancer, antibacterial, antioxidant, and antiinflammatory. This chapter is focused on the antiinflammatory activity of xanthones derivatives obtained from both natural resources and chemical synthesis. Various types of bioassay that are commonly used to examine the antiinflammatory activity of xanthones, together with their structure–activity relationship are summarized. The hydroxyl and prenyl substituent groups have contributed the most to the antiinflammatory activity of xanthones.