A cyclitol derivative as a replication inhibitor from the marine sponge Petrosia sp

A bioactive cyclitol derivative (1) was isolated from the marine sponge Petrosia sp. The chemical structure of 1 was determined as (2S)-1-O-(2',3',4',5'-tetrahydroxycyclopentyl)-3-O-(10' '-methylhexadecyl)glycerol. Compound 1 inhibited DNA replication in vitro at the level of initiation.