AGELASTATIN-C AND AGELASTATIN-D, NEW PENTACYCLIC BROMOPYRROLES FROM THE SPONGE CYMBASTELA SP., AND POTENT ARTHROPOD TOXICITY OF (-)-AGELASTATIN-A

Two new agelastatins, C (3) and D (4), along with the known compound ( -)-agelastatin A ii), were isolated from the Indian Ocean sponge Cymba stela sp. The structures were determined by analysis of spectroscopic data and chemical correlation of 4 with a common derivative 5, also pr epared from 1. Agelastatin A (1) exhibited potent activity against bri ne shrimp (LC50 1.7 ppm) in addition to insecticidal activity against larvae of beet army worm, Spodoptera exigua, and corn rootworm, Diabro tica undecimpunctata.