Marine Natural Products. XXXII.1) Absolute Configurations of C-4 of the Manoalide Family, Biologically Active Sesterterpenes from the Marine Sponge Hyrtios erecta

Abstract

Cytotoxic sesterterpenes, manoalide 25-acetals (la, lb), seco-manoalide (2), (E)-neoinanoalide (3), (Z)-neomanoalide (4), and heteronemin (6), were isolated from the marine sponge Hyrtios erecta (collected at Amami Island, Kagoshima Prefecture, Japan) by bioassay-guided separation and the absolute configurations of these manoalide family members have been determined. Manoalide 25-acetals (la, lb) were shown to exhibit in vivo antitumor activity and to inhibit the DNA-relaxing activity of mouse DNA topoisomerase I and the DNA-unknotting activity of calf thymus DNA topoisomerase II. © 1994, The Pharmaceutical Society of Japan. All rights reserved.