Sporolides A and B are polycyclic macrolides extracted from the obligate marine bacterium Salinispora tropica, which is found in ocean sediment. They are composed of a chlorinated cyclopenta[a]indene ring and a cyclohexenone moiety. They were the second group of compounds isolated from Salinispora, and were said to indicate the potential of marine actinomycetes as a source of novel secondary metabolites. The structures and absolute stereochemistries of both metabolites were elucidated using a combination of NMR spectroscopy and X-ray crystallography.