Six new polybromoindoles (9-14) have been isolated from the red alga Laurencia brongniartii. Two were optically active sulfoxides, the itomanindoles A (12) and B (13) and one was a bisindole (14). The structures of 12 and 14 were elucidated by X-ray analysis. The sulfoxides 12 and 13 were readily converted with diazomethane to the corresponding N- methyl derivatives. Treatment with acetic anhydride at room temperature gave the same ...