Schiff bases of 3-formylchromone as thymidine phosphorylase inhibitors

3-Formylchromone (1), 3-methyl-7-hydroxychromone (2) and Schiff bases of 3-formylchromone 3-19 have been synthesized and their anti-thymidine phosphorylase inhibitory activity was evaluated. Compounds 1-19 showed a varying degree of thymidine phosphorylase inhibition with IC50 values 19.77 +/- 3.25 to 480.21 +/- 2.34 mu M. Their activity was compared with the standard 7-deazaxanthine (IC50 = 39.28 +/- 0.76 mu M). Compound 12 showed an excellent thymidine phosphorylase inhibitory activity with an IC50 value of 19.77 +/- 3.25 mu M, better than the standard. Compound 4 also showed an excellent inhibitory activity (IC50 = 40.29 +/- 4.56 mu M). The parent 3-formylchromone (1) and 3-methyl-7-hydroxychromone (2) were found to be inactive. The structures of the compounds were elucidated by using spectroscopic techniques, including H-1 NMR, EI MS, IR, UV and elemental analysis. (C) 2009 Elsevier Ltd. All rights reserved.