text: Since the 1960s, marine organisms with robust chemical defense systems have been targeted for “molecular mining,” a method of drug discovery that probes organisms of interest for useful compounds.  Chemical agents involved in the defense systems of these organisms often exhibit antibacterial, anti-inflammatory, and chemotherapeutic properties. Capnellene derivatives and their terrestrial counterparts, hirsutanes, demonstrate antibacterial and antitumor properties with pharmacological potential.