Design, synthesis, molecular docking and molecular dynamics studies of novel triazolothiadiazine derivatives containing furan or thiophene rings as anticancer agents.

Breast cancer is the most common cancer type amoung post-menopausal women. Aromatase inhibitors were used in the treatment of patients. However, drug resistance may develop in long-term drug use, especially in 3rd and 4th stage (advanced) cancer cases. Therefore, there is a constant need for new agents. In this study, new triazolothiadiazine derivatives were synthesized and their anticancer activities were investigated. Compounds 2k, 2s, and 2w showed inhibitor activity against MCF-7 cell line with IC50 = 4.63 ± 0.10; 2.23 ± 0.16; 3.13 ± 0.08 µM value, respectively. As a result of in vitro aromatase enzyme inhibition test, compound 2s was the most active derivative with IC50 = 0.058 ± 0.023 µM. In addition, DNA synthesis inhibition percentages of the compounds were measured by the BrdU method. The intermolecular interactions of the promising compounds with aromatase enzyme were investigated through the SP docking approach, which revealed significant binding interaction energies associated with these compounds. Following that, the interaction's stability was assessed using a typical atomistic 100 ns dynamic simulation study. A number of parameters derived from MD simulation trajectories were computed and validated for the protein-ligand complex's stability under the dynamic conditions.

Design and synthesis of novel chalcone derivatives and evaluation of their inhibitory activities against acetylcholinesterase.

According to the cholinergic hypothesis, an increase in the acetylcholine level in Alzheimer's disease patients relatively slows down the symptoms of the disease. The most commonly used drug, donepezil, is a cholinesterase inhibitor. In this study, 12 new chalcones (2a-l) were designed and synthesized. In biological activity studies, the acetylcholinesterase (AChE) and butyrylcholinesterase inhibitory potentials of all compounds were evaluated using the in vitro Ellman method. The biological evaluation showed that compounds 2d, 2f, 2j, and 2l displayed significant activity against AChE. The compounds 2d, 2f, 2j, and 2l displayed IC50 values of 0.042, 0.024, 0.053, and 0.033 µM against AChE, respectively. The reference drug donepezil (IC50 = 0.021 µM) also displayed significant inhibition of AChE. The inhibitory activities of these compounds for ß-amyloid plaque aggregation were investigated. The enzyme kinetic study was performed to observe the effect of the most active compound 2f on the substrate-enzyme relationship, and a mixed-type inhibition of AchE was determined. Further, docking simulation also revealed that these compounds (2d, 2f, 2j, and 2l) interacted with the enzyme active site in a similar manner to donepezil. The most active derivative, compound 2f, interacted with the amino acids Trp286, Phe295, Tyr341, Trp86, and Glu202.

Synthesis of novel benzothiazole derivatives and investigation of their enzyme inhibitory effects against Alzheimer's disease.

The use of dual acetylcholinesterase (AChE)-monoamine oxidase B (MAO-B) inhibitors is a new approach in the treatment of Alzheimer disease (AD). In this work, 14 new benzothiazoles (4a-4n) were designed and synthesized. In biological activity studies, the AChE, butyrylcholinesterase (BChE), MAO-A and MAO-B inhibitory potentials of all compounds were evaluated using the in vitro fluorometric method. Additionally, amyloid beta (Aß)-aggregation inhibitory effects of active compounds were evaluated by means of an in vitro kit-based method. The biological evaluation showed that compounds 4a, 4d, 4f, 4h, 4k and 4m displayed significant activity against AChE and MAO-B enzymes. Compound 4f displayed inhibitory activity against AChE and MAO-B enzyme with IC50 values of 23.4 ± 1.1 nM and 40.3 ± 1.7 nM, respectively. It has been revealed that compound 4f may have the potential to inhibit AChE and MAO-B enzymes, as well as the ability to prevent the formation of beta amyloid plaques accumulated in the brains of patients suffering from AD. In silico studies also support the obtained biological activity findings. Compound 4f provided strong interactions with the active site of both enzymes. In particular, the interaction of compound 4f with flavin adenine dinucleotide (FAD) in the MAO-B enzyme active site is a promising and exciting finding.