Synthesis, biological evaluation, and molecular docking studies of novel N-substituted piperazine-tethered thiophene-3-carboxamide selenides as potent antiproliferative agents with EGFR kinase inhibitory activity.

In the context of structural investigation and optimization of various potential EGFR inhibitors, a novel series of asymmetrical piperazine-tethered trisubstituted thiophene-3-carboxamide selenide derivatives were synthesized and evaluated for their antiproliferative potential against selected human cancer cell lines. These derivatives, built based on a previously identified hit molecule, were synthesized via multiple-step reactions, including optimization of the C-Se cross-coupling reaction. Two compounds, 17i and 18i, displayed significant cytotoxicity (IC50 value: 4.82 ± 0.80 µM and 1.43 ± 0.08 µM) against HCT116 and A549 cancer cell lines, respectively. Quantitative analysis of apoptotic stages using Annexin V-FITC/PI double staining validated their apoptotic potential. Further, compound 18i demonstrated a remarkable inhibition of EGFR kinase, with an IC50 concentration of 42.3 nM. The lead compound 18i, with remarkable in vitro cytotoxicity, apoptosis induction capability, and EGFR inhibition, emerges as a promising candidate for anticancer therapy.

Development of trisubstituted thiophene-3-arboxamide selenide derivatives as novel EGFR kinase inhibitors with cytotoxic activity.

Overexpression of EGFR is one of the eminent oncogenic drivers detected in the development of several human cancers. The increasing incidences of mutation-based resistance in the tyrosine kinase domain call upon the need for the development of a newer class of small-molecule TK inhibitors. Accordingly, a new series of symmetrical trisubstituted thiophene-3-carboxamide selenide derivatives was developed via the hybridization of complementary pharmacophores. Most of the compounds showed a modest to excellent antiproliferative action at 20 µM concentration. The utmost antiproliferative activity was portrayed by compound 16e on the selected cancer cell lines with IC50 < 9 µM, the lowest being 3.20 ± 0.12 µM in the HCT116 cell line. Further, it also displayed an impressive EGFR kinase inhibition with an IC50 value of 94.44 ± 2.22 nM concentration. As a corollary of the reported EGFR inhibition, the nature, energy, and stability of the binding interactions were contemplated via in silico studies.

Molecular modeling evaluation of non-steroidal aromatase inhibitors.

A recent discovery of aromatase crystal structure triggered the efforts to design novel aromatase inhibitors for breast cancer therapy. While correlating docking scores with inhibitory potencies of known ligands, feeble robustness of scoring functions toward prediction was observed. This prompted us to develop new prediction models using stepwise regression analysis based on consensus of different docking and their scoring methods (GOLD, LIGANDFIT, and GLIDE). Quantitative structure-activity relationships were developed between the aromatase inhibitory activity (pIC(50) ) of flavonoid derivatives (n=39) and docking scores and docking descriptors. QSAR models have been validated internally [using leave-one-out cross-validated r(2)(cv) (LOO-Q2))] and externally to ensure the predictive capacity of the models. Model 2 [M2] developed using consensus of docking scores of scoring functions viz. ASP, potential of mean force and DOCK Score (r(2)(cv)=0.850, r(2) = 0.870, r(2)(pred) = 0.633, RMSE = 0.363 µm, r(2)(m(test)) =0.831, r(2)(m(overall)) =0.832) was found to be better in predicting aromatase inhibitory potency (pIC(50) ) compared to the Model 1 [M1] based on docking descriptors (r(2)(cv)= 0.848, r(2) = 0.825, r(2)(pred) =0.788, RMSE=0.421µm, r(2)(m(test)) =0.808, r(2)(m(overall)) =0.821). It has been observed that the natural flavonoids and their derivatives were less potent compared to these scaffolds with imidazolylmethyl substitution owing to the interaction of nitrogen atom of the imidazole ring toward the heme (Fe(3+) ) of the aromatase. Results confirm the potential of our methodology for the design of new potent non-steroidal aromatase inhibitors.

Iodine-sodium cyanoborohydride-mediated reductive ring opening of 4,6-O-benzylidene acetals of hexopyranosides.

A quick, efficient and convenient method for the regiospecific reductive ring opening of 4,6-O-benzylidene acetals of O-/S-alkyl/aryl glycosides of mono- and disaccharides, leading to the exclusive formation of the corresponding 6-O-benzyl ethers, using sodium cyanoborohydride in the presence of molecular iodine, is reported. It has been observed that common protecting groups such as ethers and esters are well tolerated under the conditions studied. The reaction was proved unsuccessful when applied to a glucosamine-derived benzylidene acetal.