A New α,β,γ,δ-Unsaturated carboxylic acid and three new cyclic peroxides from the marine sponge, Monotria japonica, which selectively lyse starfish oocytes without affecting nuclear morphology Original Research Article

The marine sponge Monotria japonica contains cytolytic constituents, which have been fractionated to a new α,β,γ,δ-unsaturated carboxylic acid designated monotriajaponide A (1) and three new cyclic peroxides designated monotriajaponides B (2), C (3), and D (4), in addition to a known peroxide (5) and a known α,β-unsaturated ester (6). The structures were determined on the basis of spectroscopic data. Compounds 1–5 lysed immature starfish (Asterina pectinifera) oocytes without affecting nuclear morphology at the minimum effective concentrations of 50, 6.3, 6.3, 6.3, and 13 μg/mL, respectively. On the other hand, compound 6, at the minimum effective concentration of 25 μg/mL, lysed both oocyteʹs plasma membrane and the nuclear envelope.