The antitumor activity of naturally occurring chromones: A review

Chromones are a group of compounds widely distributed in nature with wide range of biological activities, including antitumor, antimicrobial, antiviral, anti-inflammatory, antioxidant, and so on. This review mainly summarizes chromones with antitumor activity in nature and classifies them into three groups, including chromanones, simple chromones, and fused chromones. They exhibit antitumor activity through broad range of mechanisms including cytotoxicity, antimetastasis, antiangiogenesis, chemoprevention, immune regulation, etc.