New avarone and avarol derivatives from the marine sponge Dysidea cinerea.

Six new avarol and avarone derivatives, 3'-hydroxyavarone [3], 3',6'-dihydroxyavarone [4], 6'-hydroxyavarol [5], 6'-acetoxyavarol [6], 6'-acetoxyavarone [7], and 6'-hydroxy-4'-methoxyavarone [8], are reported from the Red Sea sponge Dysidea cinerea. The structures of the new compounds were determined by spectroscopic data, mainly 1D and 2D nmr measurements. The absolute configurations of 5, 6, and 7, and most likely also of 3, 4, and 8, were established on the basis of cd measurements to be the same as that of avarol. Several of the new compounds are cytotoxic, possess antimicrobial activities, and have anti-HIV-1 reverse transcriptase activities; the most active is compound 8.