Bioassay-guided fractionation of organic extracts of Cladosporium herbarum, isolated from the marine sponge Callyspongia aerizusa, yielded two new macrolide metabolites: pandangolide 3 and 4 (1 and 2) and the known fungal metabolites pandangolide 2 (3), cladospolide B (4), and iso-cladospolide B (5). Also isolated were the antimicrobially active (against Bacillus subtilis and Staphylococcus aureus) furan carboxylic acids: Sumiki's acid (6) and its new derivative, acetyl Sumiki's acid (7). All structures were elucidated by spectroscopic methods.