Benzothiazole Derived Ether Hybrids as Potent Anti-Thymidine Phosphorylase Agents: Synthesis, In Vitro, and Computational Investigations

This work is based on the synthesis of new ether derivatives bearing benzothiazole (BTA) scaffold through multistep reaction process. Initially, BTA was prepared by refluxing 4-hydroxybenzaldehyde with aminothiophenol having sodium metabisulfite in dimethylformamide (DMF); subsequently, the product was further refluxed with different substituted benzyl and alkyl bromides in acetone to get ether hybrids of BTA in good yields. Structurally, these compounds were confirmed by means of 1H, 13C-NMR, and mass spectrometry and evaluated for in vitro thymidine phosphorylase (TP) inhibitory activity. In the series, seven compounds attributed excellent inhibition against TP enzyme better than the standard. Similarly, three compounds showed good activity, whereas two compounds were found inactive. Moreover, all these compounds showed no toxicity to normal human fibroblast cell line (BJ cell line). In addition, Gaussian calculations were performed on the 6-31++g(d,p) basis set to examine the 13 synthesized compounds at the B3LYP, HF, and M062X levels. Additionally, molecular docking calculations were performed on TP enzyme proteins (PDB IDs: 4EAD, 2WK6, and 4LHM), and absorption, distribution, metabolism, excretion/toxicity (ADME/T) calculations were performed to investigate the effects and responses of these compounds in human metabolism.