Seven new meroditerpenoids, from the marine sponge Strongylophora strongylata, that inhibited the maturation of starfish oocytes

Abstract

Seven new meroditerpenoids, strongylophorines 13–19 (1–7), have been isolated together with the four known strongylophorines 2 (8), 3 (9), 4 (10), and 8 (11) by a screening method using oocytes of the starfish Asterina pectinifera from a marine sponge Strongylophora strongylata collected at Iriomote Island, Okinawa, Japan. The structures were assigned according to their spectral data. Ten strongylophorines inhibited the maturation of starfish oocytes in the range 1.1–37.6 μM (IC₅₀), while strongylophorine 4 (10) was not active at 250 μM.

Keywords:

• Meroditerpenoid
• Strongylophorine
• Starfish oocyte assay
• Marine sponge
• Strongylophora strongylata

Acknowledgements

This work was supported in part by a grant from the Naito Foundation to MN. We thank Dr H. Watanabe (Varian Technologies Japan. Ltd.) for the measurement of several NMR spectra.