Tropolone, produced by Pseudomonas sp., is a 7-membered ring bearing hydroxy and carbonyl groups which provides a useful scaffold for chemical modification. Tropolone, the causal agent of seedling blight of rice, is a potent root growth and seed germination inhibitor at concentrations as low as 10 ppm. Tropolone has broad pharmacological profile, including insecticidal, antiviral, antibiotic, adrenergic and catechol-​O-​methyl transferase (COMT) inhibitory activities.