The potential of epoxide-containing marine natural products: sources, structures and bioactivities

Epoxide-containing natural products represent a structurally diverse and biologically potent class of secondary metabolites. Their characteristic three-membered cyclic ether moiety imparts high chemical reactivity and significant pharmacological potential, as evidenced by several clinically approved epoxide-bearing drugs. However, the relatively limited structural diversity of terrestrial epoxides has driven growing interest in marine-derived alternatives. This review comprehensively summarizes 1360 epoxide-containing marine natural products (ECMNPs) reported between 2005 and 2024, focusing on their biological sources, structural diversity, and bioactivities. Terpenoids, particularly diterpenoids from Cnidaria, dominate this chemical space, comprising over 75 % of all ECMNPs. These compounds exhibit a wide range of pharmacological properties, including cytotoxic, anti-inflammatory, antibacterial, antifungal, and antiviral activities. Notably, among these activities, cytotoxicity emerges as the most prominent characteristic of ECMNPs. This review also summarizes the structure-activity relationship (SAR) studies associated with the cytotoxicity of these compounds. In summary, our objective is to provide an overview of the research progress concerning ECMNPs, with the aim of fostering their continued development and utilization.