3,4-Dihydro-2, 2-Dimethyl-H-1 Benzopyran-6-Butyric Acid

Details of the preparation from zanthoxylol of a new anti-sickling agent, 3,4-dihydro-2,2-dimethyl-2-H-1 bezophyran-6-butyric acid, DBA, are given. The reaction involved converting zanthoxylol to its iodo-compound. This in turn was subsequently hydrolysed to DBA. DBA dose-dependently inhibited carrageein-induced rat paw oedema. The ED 50 was approximately 60 mg kg -1 . Indomethacin and aspirin were similarly effective with ED 50 of 2.2 and 91 mg kg -1 respectively. DBA also inhibited acetic acid induced squirming in mice. The ED 50 was 58 mg kg -1 compared with 75 mg kg for aspirin. DBA, indomethacin and aspirin inhibited generation of prostaglandin-like activity by isolated segments of rabbit jejunum as well as the production of PG-like activity from arachidonic by cell-free homogenates of guinea-pig lung. It is concluded that the mechanism of anti-inflammatory and analgesic activity of DBA, like that of aspirin and indomethacin, may involve inhibition of prostaglandin synthesis.