Synthesis of 5-Thioxo-hexahydrobenzo[b]thiopheno[2,3-d]-1,2,4-triazolo[1,5-c]pyrimidines and Related Compounds Based on Cyclocondensations of 2-Isothiocyanato-3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophene

Pharmacophore-based, rationale design, and efficient synthesis of novel tetrahydrobenzo[b]thiophene candidates as potential dual Topo I/II inhibitors and DNA intercalators

A series of tetrahydrobenzo[b]thiophene derivatives was designed and synthesized as dual topoisomerase (Topo) I/II inhibitors implicating potential DNA intercalation. Ethyl-2-amino-3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophene-4-carboxylate (1) was prepared by modification of the Gewald reaction procedure using a Fe2O3 nanocatalyst and then it was used as a building block for the synthesis of tetrahydrobenzo[b]thiophene candidates (2-14). Interestingly, compound 14 showed the best cytotoxic potential against hepatocellular, colorectal, and breast cancer cell lines (IC50 = 7.79, 8.10, and 3.53 µM), respectively, surpassing doxorubicin at breast cancer (IC50 = 4.17 µM). Meanwhile, the Topo I and II inhibition assay displayed that compound 3 could exhibit the best inhibitory potential among the investigated candidates (IC50 = 25.26 and 10.01 nM), respectively, in comparison to camptothecin (IC50 = 28.34 nM) and doxorubicin (IC50 = 11.01 nM), as reference standards. In addition, the DNA intercalation assay showed that compound 14 could display the best binding affinity with an IC50 value of 77.82 µM in comparison to doxorubicin (IC50 = 58.03 µM). Furthermore, cell cycle and apoptosis analyses described that compound 3 prompts the G1 phase arrest in michigan cancer foundation-7 cancer cells and increases the apoptosis ratio by 29.31% with respect to untreated cells (2.25%). Additionally, the conducted molecular docking assured the promising binding of the investigated members toward Topo I and II with potential DNA intercalation. Accordingly, the synthesized compounds could be treated as promising anticancer candidates for future optimization.

Fragment merging approach for design, synthesis, and biological assessment of urea/acetyl hydrazide clubbed thienopyrimidine derivatives as GSK-3β inhibitors

New thienopyrimidine derivatives were designed and synthesized as GSK-3β inhibitors based on the structure of active binding site of GSK-3β enzyme. In this study, compounds 6b and 6a were found to be moderate GSK-3β inhibitors with IC50s 10.2 and 17.3 μM, respectively. Molecular docking study was carried out by docking the targeted compounds in the binding site of the GSK-3β enzyme using the MOE program. Moreover, ADME study was performed to predict certain pharmacokinetic properties. The results showed that all synthesized compounds may not be able to penetrate the blood brain barrier; so, the chances of CNS side effects are predicted to be low. CYP1D6 is predicted to be inhibited by compounds (5a, 5d, 6a, 9a and 9b), So drug-drug interactions are expected upon administration of these compounds.