STUDIES ON THE SYNTHESIS AND STRUCTURE-ACTIVITY-RELATIONSHIPS OF 5-(3'-INDOLAL)-2-THIOHYDANTOIN DERIVATIVES AS ALDOSE REDUCTASE ENZYME-INHIBITORS

A new series of 5-(3'-indolal)-2-thiohydantoin derivatives was synthes ized and tested for the ability to inhibit bovine lens aldose reductas e (AR) enzyme. The compounds were prepared by condensation of substitu ted indole-3-aldehyde derivatives with 2-thiohydantoin. The capacity o f inhibiting the semi-purified bovine lens enzyme in vitro was observe d for several of the compounds tested. One of them was found to be eff ective in reducing the enzyme activity compared with a corresponding w ell-known AR inhibitor.