Natural and Synthetic Derivatives of Discorhabdin C, a Cytotoxic Pigment from the New Zealand Sponge Latrunculia cf. bocagei

Modification of the spiro-cyclohexadienone skeleton of discorhabdin C (3) led to a series of derivatives 6–11. The biological properties of this series were evaluated in a wide range of screens for selective cytotoxicity, antifungal, and antimicrobial properties. The structure and biological properties of a further discorhabdin, discorhabdin E (5), from a New Zealand sponge Latrunculia cf. bocagei are also presented.