Sponges are a vital source of pharmaceutically active secondary metabolites, of which the main structural types are alkaloids and terpenoids. Many of these compounds exhibit biological activities. Focusing specifically on diterpenoids, this article reviews the structures and biological activities of 228 diterpenes isolated from more than 33 genera of sponges from 2009 to 2022. The Spongia sponges produce the most diterpenoid molecules among all genera, accounting for 27%. Of the 228 molecules, 110 exhibit cytotoxic, antibacterial, antifungal, antiparasitic, anti-inflammatory, and antifouling activities, among others. The most prevalent activity is cytotoxicity, present in 54 molecules, which represent 24% of the diterpenes reported. These structurally and biologically diverse diterpenoids highlight the vast, yet largely untapped, potential of marine sponges in the discovery of new bioactive molecules for medicinal use.
