Actinopyrone A is a pyrone isolated from S. pactum with diverse biological activities. It has selective and potent antimicrobial activity against H. pylori (MIC = 0.1 ng/mL) with no activity against other Gram-negative bacteria including E. coli, K. pneumoniae, P. aeruginosa, and B. fragilis. Actinopyrone A also mildly inhibits growth of Gram-positive bacteria and dermatophytes with MIC values ranging from<6.25 to 25 μg/mL. Intravenous administration of actinopyrone A (30 μg/kg) increases coronary blood flow in dogs by 196.2%.