Synthesis, characterization and biological evaluation of indomethacin derived thioureas as purinergic (P2Y1, P2Y2, P2Y4, and P2Y6) receptor antagonists

Synthesis, structure-activity relationships and biological evaluation of benzimidazole derived sulfonylurea analogues as a new class of antagonists of P2Y1 receptor

The P2Y receptors are responsible for the regulation of various physiological processes including neurotransmission and inflammatory responses. These receptors are also considered as novel potential therapeutic targets for prevention and treatment of thrombosis, neurological disorders, pain, cardiac diseases and cancer. Previously, number of P2Y receptor antagonists has been investigated but they are less potent and non-selective with poor solubility profile. Herein, we present the synthesis of new class of benzimidazole derived sulfonylureas (1a-y) as potent antagonists of P2Y receptors, with the specific aim to explore selective antagonists of P2Y1 receptors. The efficacy and selectivity of the synthesized derivatives 1) against four P2Y receptors i.e., t-P2Y1, h-P2Y2, h-P2Y4, and r-P2Y6Rs was carried out by calcium mobilization assay. The results revealed that except 1b, 1d, 1l, 1m, 1o, 1u, 1v, 1w, and 1y, rest of the synthesized derivatives exhibited moderate to excellent inhibitory potential against P2Y1 receptors. Among the potent antagonists, derivative 1h depicted the maximum inhibition of P2Y1 receptor in calcium signalling assay, with an IC₅₀ value of 0.19 ± 0.04 µM. The potential of inhibition was validated by computational investigations where bonding and non-bonding interactions between ligand and targeted receptor further strengthen the study. The best identified derivative 1h revealed the same binding mechanism as that of already reported selective antagonist of P2Y1 receptor i.e (1-(2- (2-tert-butyl-phenoxy) pyridin-3-yl)-3-4-(trifluoromethoxy) phenylurea but the newly synthesized derivative exhibited better solubility profile. Hence, this derivative can be used as lead candidate for the synthesis of more potential antagonist with much better solubility profile and medicinal importance.

New acetylphenol-based acyl thioureas broaden the scope of drug candidates for urease inhibition: synthesis, in vitro screening and in silico analysis

Helicobacter pylori urease remains a validated drug target for the eradication of pervasive chronic stomach infection that leads to severe human health diseases such as gastritis and stomach cancer. The increased failure of current treatment protocols because of resistance to broadband antibiotics, severe side effects and low compliance underscore the need for a targeted eradication therapy. Therefore, in the present research, we have developed a new series of acetylphenol-based acyl thioureas that can potentially provide a new template for drug candidates to inhibit urease enzyme. Newly synthesized compounds 7a-j were evaluated for urease inhibitory strength using thiourea as a positive control. In vitro inhibitory results revealed that all the tested compounds were significantly potent than the standard drug. The most active lead 7f competitively inhibited the enzyme and displayed an IC₅₀ value of 0.054 ± 0.002 μM, a ~413-fold strong inhibitory potential than thiourea (IC₅₀ = 22.3 ± 0.031 μM). Various insightful structure-activity relationships were developed showing the key structural requirements for potent inhibitory effects. Molecular docking analysis of 7f inside the active pocket of urease suggested several important interactions with amino acid residues such as ILE411, MET637, ARG439, GLN635, ALA636 and ALA440. Finally, pharmacokinetic properties suggested that the tested derivatives are safe to develop as low-molecular-weight drugs to treat ureolytic bacterial infections.