Synthesis and anti-inflammatory activity of natural and semisynthetic geranyloxycoumarins

Nine new 7-geranyloxycoumarin derivatives differently substituted at position 8 were semi-synthesised. Their topical anti-inflammatory activity was evaluated using the Croton oil ear test in mice as a model of acute inflammation. Auraptene (7-geranyloxycoumarin), its 8-methoxy (collinin, 1) and 8-acetoxy derivatives (5) (1 μmol/cm2) provoked 50% oedema reduction, similarly to 0.25 μmol/cm2 of the reference drug indomethacin, a nonsteroidal anti-inflammatory drug.