The use of privileged scaffolds as starting point for the construction of libraries of bioactive compounds is a widely used strategy in drug discovery and development. Scaffold decoration, morphing and hopping are additional techniques that allow to modify the privileged framework chosen and better explore the chemical space around it. In this study, two series of highly functionalized pyrimidine and pyridine derivatives were synthesized by scaffold morphing approach of triazine compounds obtained previously as antiviral agents. Newly synthesized azines were evaluated against lymphoma, hepatocarcinoma, and colon epithelial carcinoma cells showing in five cases acceptable to good anticancer activity associated to low cytotoxicity on healthy fibroblasts. Finally, ADME in vitro studies were conducted on the best derivatives of the two series showing good passive permeability and resistance to metabolic degradation.

Imidazo[1,2-a]pyridines have been studied regarding drug development. The objective of this work was to evaluate the antileukemic capacity of imidazo[1,2-a]pyridine derivatives by screening its ability as a pro-oxidant. Imidazo[1,2-a]pyridine derivatives were synthesized and oral bioavailability and toxicity were analyzed in silico. Redox screening was performed on human Kasumi, KG-1, K562 and Jurkat leukemia cells. The imidazo[1,2-a]pyridine derivative and the most responsive leukemic cell were selected for cytotoxicity, cell proliferation, cell senescence and oxidative stress assays. The predictive toxicity analysis showed a possible effect on the reproductive system, but without mutagenic, carcinogenic or irritability effects. MRK-107 against K562 cells was the compound that showed the best redox profile. MRK-107 did not induce cell death in K562 and monocyte cells. However, this compound was able to decrease cell proliferation and increase cell senescence after 48 and 72 hours. Furthermore, MRK-107 induced oxidative stress in K562 cells after 72h, increasing lipid peroxidation and decreasing reduced glutathione (GSH) contents. This study demonstrated that MRK-107-induced senescence with the involvement of oxidative stress as a possible mechanism of action, addressing this compound as a potential antitumor drug against chronic myeloid leukemia.

New [1,2]dithiolo[3,4-b]pyridine-5-carboxamides were synthesized through the reaction of dithiomalondianilide (N,N'-diphenyldithiomalondiamide) with 3-aryl-2-cyanoacrylamides or by a three-component reaction involving aromatic aldehydes, cyanoacetamide and dithiomalon- dianilide in the presence of morpholine. The structure of 6-amino-4-(2,4-dichlorophenyl)- 7-phenyl-3-(phenylimino)-4,7-dihydro-3H-[1,2]dithiolo[3,4-b]pyridine-5-carboxamide was con-firmed using X-ray crystallography. To understand the reaction mechanism in detail, density functional theory (DFT) calculations were performed with a Grimme B97-3c composite computa-tional scheme. The results revealed that the rate limiting step is a cyclization process leading to the closure of 1,4-dihydropyridine ring with an activation barrier of 28.8 kcal/mol. Some of dithiolo[3,4-b]pyridines exhibited moderate herbicide safening effects against 2,4-D . Additional-ly, ADMET parameters were calculated and molecular docking studies were performed to identify potential protein targets.