New 2-alkoxycyanopyridine derivatives as inhibitors of EGFR, HER2, and DHFR: Synthesis, anticancer evaluation, and molecular modeling studies

New series of substituted 2-alkoxycyanopyridine derivatives were synthesized and evaluated for their in vitro and in vivo anticancer activities. Comparing the evaluated activities against cancer cell lines to the broad-spectrum anticancer doxorubicin, and the kinase inhibitor sorafenib, compounds 3a, 4b, 4c, 7a, and 8d demonstrated superior anticancer efficacy with elevated safety profiles and selectivity indices, particularly against MCF7 breast cancer. For exploration of their mechanism of action, assays for inhibition of EGFR, HER2 kinase, and DHFR were performed. The promising synthesized compounds exhibited potent dual kinase EGFR/HER2 inhibitory activity with IC50values of 0.248/0.156 μM for 4b and 0.138/0.092 μM for 4c. Additionally, with IC50 values of 0.138 and 0.193 M, respectively, 4b and 4c had the greatest DHFR inhibitory activity that was comparable to methotrexate. In the MCF7 breast cancer cell line, they caused arrest at the S phase of the cell cycle and exhibited apoptosis induction activity. With restored caspase-3 immunoexpression, the anti-breast cancer assay performed in vivo of 4b and 4c demonstrated a substantial decrease in tumor volume. Results from molecular modeling were in agreement with biological assays proving the importance of the 3-caynopyridine, two substituted phenyl rings attached to central pyridine ring, and propoxy side chain moieties for binding with the receptors. As 4c works by inhibiting both EGFR/HER2 kinase, DHFR enzymes, in addition to cellular apoptosis, it could be viewed as a model of compounds possessing a multi-targeting anticancer activity. Collectively, compounds 4b and 4c might represent prototypes for further development as anticancer molecules.

Diarylpyrazole Ligated Dihydropyrimidine Hybrids as Potent Non-Classical Antifolates and Their Efficacy Against Plasmodium falciparum

A series of diarylpyrazole clubbed dihydropyrimidine derivatives (J1-J30) was synthesized under microwave-assisted heating conditions by employing Biginelli reaction methodology and utilizing triethylammonium acetate both as a catalyst and as reaction medium, leading towards a greener reaction pathway. The synthesized entities were screened for their antimalarial efficacy against a Plasmodium falciparum strain in vitro. The active entities (J9, J15, J21, J25, and J27) obtained out of the in vitro screening were further evaluated for their enzyme inhibitory potency against the Pf-DHFR enzyme in vitro as well as in silico using Glide. Furthermore, the active scaffolds were tested for their cytotoxicity against Vero cells, proving their nontoxic behavior and selectivity. The ADME parameters were also evaluated and predicted in silico, indicating good oral bioavailability of the compounds.

Ultrasound mediated synthesis of dihydropyrano[3,2-d][1,3]dioxin-7-carbonitrile derivatives in H2O/EtOH medium

A one-pot cyclocondensation of 1,3-dioxane-5-one (1) with malononitrile and aromatic aldehydes in aqueous sodium hydroxide under ultrasonic irradiation furnishes a series of pyrano[3,2-d][1,3]dioxin derivatives 3. Reactions are completed after a few minutes and the precipitated products are purified by simple crystallization from ethanol. The reaction with ethyl cyanoacetate instead of malononitrile gives the respective analogous products in high yields.