Structure-activity relationships of tyrosinase inhibitory combinatorial library of 2,5-disubstituted-1,3,4-oxadiazole analogues

Here the tyrosinase inhibition studies of library of 2,5-disubstituted-1,3,4-oxadiazoles have been reported and their structure-activity relationship (SAR) also have been discussed. The library of the oxadiazoles was synthesized under the microwave irradiation and was structures of these were characterized by different spectral techniques. From this study it could be concluded that for a better inhibition of tyrosinase, electronegative substitution is essential as most probably the active site of the enzyme contain some hydrophobic site and position is also very important for the inhibition purposes due to the conformational space. The electronegativity of the compounds is somewhat proportional to the inhibitory activity. The compound 3e (3 '-[5-(4 '-bromophenyl)-1,3,4-oxadiazol-2-yl]pyridine) exhibited most potent (IC50 = 2.18 mu M) inhibition against the enzyme tyrosinase which is more potent than the standard potent inhibitor L-mimosine IC50 = 3.68 mu M). This molecule can be the best candidate as a lead compound for further development of drug for the treatments of several skin disorders. (c) 2005 Elsevier Ltd. All rights reserved.