HYDROXYL AND HYDROPEROXY RADICAL SCAVENGING BY COPPER(II) CHELATES RELATED TO NONSTEROIDAL ANTIINFLAMMATORY DRUGS

Solutions of dequalinium chloride with and without added hydrogen pero xide were irradiated in buffer solutions with simulated sunlight at 23 +/- 1 degrees C. The photodegradation of dequalinium chloride solutio n and hydrogen peroxide in buffer at pH 7.0 and 10.7 with the copper(I I) chelates of ethyl N-substituted 4-hydroxy-5-oxo-3-pyrroline-3-carbo xylates and 3,5-diisopropylsalicylic acid showed that only the copper( II) chelate of the latter scavenged hydroxyl radicals at pH 7.0. All t he compounds tested showed hydroxyl radical scavenging effects at pH 1 0.7 and were scavengers for the hydroperoxy radical at pH 7.0. The str ucture-activity relationships in the compounds tested are discussed.