In the course of our search for bioactive metabolites from marine organisms, new hexylitaconic acid derivatives (1-4), along with (3S)-hexylitaconic acid (5), were isolated from a sponge-derived fungus Penicillium sp. Based on the NMR and MS data, the structures of compounds 1-4 were defined as α,β-dicarboxylic acid derivatives, such as hexylitaconic acid and tensyuic acids which were previously reported as metabolite of Aspergillus niger, Penicillium striatisporum, or Apiospora montagnei. The isolated compounds were evaluated for cytotoxicity against a panel of five human solid tumor cell lines, and for anti-inflammatory activity gauged by their inhibitory effects on the production of major pro-inflammatory mediators (nitric oxide (NO), interleukin (IL)-6, tumor necrosis factor (TNF)-α, and IL-1β) in murine macrophage cells. Compounds 1 and 4 showed weak inhibition of IL-1β production at the concentration of 200 µM.