Spirolaxine is a long-chain phthalide produced by the fungus S. laxum that has antibacterial properties. Spirolaxine is a potent anti-H. pylori agent (MIC = 0.2 μg/cm3) with weak activity against E. coli. Spirolaxine (1-40 μM) inhibits proliferation of endothelial (BMEC, HUVEC) and tumor (LoVo, HL-60) cells in culture. B. megaterium and C. echinulate produce hydroxylated metabolites of spirolaxine when given spirolaxine as a substrate.
