Unveiling piperazine-quinoline hybrids as potential multi-target directed anti-Alzheimer's agents: design, synthesis and biological evaluation.

Multi-target directed ligands (MTDLs) have recently been popularized due to their outstanding efficacy in combating the complicated features of Alzheimer's disease. This study details the synthesis of piperazine-quinoline-based MTDLs through a multicomponent Petasis reaction, targeting multiple factors such as AChE, BuChE, metal chelation to restore metal dyshomeostasis, and antioxidant activity. Some of the synthesized compounds exhibited notable inhibitory activity against AChE and BuChE enzymes at specific concentrations. Among the synthesized compounds compound (95) containing a 4-chloroaniline moiety and a 4-methoxybenzyl group displayed the most promising inhibitory activities against AChE (IC50 3.013 µM) and BuChE (IC50 = 3.144 µM). Compound (83) featuring 2-methoxyaniline and 4-fluorobenzyl substituents, exhibited the highest BuChE inhibition (IC50 1.888 µM). Notably, compound (79) demonstrated 93-times higher selectivity for BuChE over AChE. Molecular docking and molecular dynamics simulations were also performed to explore the binding modes and stability of these compounds with the AChE amd BuChE proteins. Further, kinetics study was performed against AChE for comounds (83 and 95) which indicated mixed inhibition of the enzyme by these compounds, Amongs the synthesized compounds, nine compounds were assessed for their antioxidant activity, displaying significant antioxidant properties with IC50 values ranging from 156 µM to 310 µM. Moreover, all the compounds demonstrated metal chelating tendency with Cu+2, Zn+2, Fe+2, Fe+3 and Al+3. This study provides insights into the design of novel MTDLs, highlighting compound (95) as a potential candidate for combating Alzheimer's disease.

In silico analysis, synthesis and biological evaluation of DHFR inhibitors.

INTRODUCTION: Malaria is one of the varieties of fatal diseases caused by a protozoan parasite that is now considered to be the greatest global health challenge. A parasite of Plasmodium species triggers it transmitting the disease to humans by the bites of female Anopheles mosquitoes. AIM: To screen out designed molecules by molecular docking analysis and assess their pharmacokinetic properties using SwissADME. To synthesize the designed compounds. To characterize the synthesized compounds by TLC, melting point, IR spectroscopy, mass spectrometry, 1H NMR, and 13C NMR. To evaluate the synthesized compounds for antimalarial activity. MATERIALS AND METHODS: In silico analysis was performed with SWISSADME, and molecular docking was performed by AutoDock Vina version 4.2. In vitro antimalarial activity study was performed. RESULTS: In-vitro studies of synthesized molecules showed that compounds C2 (IC50 1.23), C6 (IC50 0.48), C10 (IC50 0.79), and C14 (IC50 0.19) possess good antimalarial activity. CONCLUSIONS: 7-chloroquinoline-piperazine derivatives exhibited potential antimalarial compounds for pf-DHFR inhibitors.

The β-Secretase Enzyme BACE1: A Biochemical Enigma for Alzheimer's Disease.

Beta site amyloid precursor protein cleaving enzyme 1 (BACE1) is a rational target in Alzheimer's Disease (AD) drug development due to its role in amyloidogenic cleavage of Amyloid Precursor Protein (APP) in generating Amyloid ß (Aß). This ß-secretase cleaves not only Amyloid Precursor Protein (APP) and its homologues, but also small series of substrates including neuregulin and ß subunit of voltage-gated sodium channel that play a very important role in the development and normal function of the brain. Moreover, BACE1 is modulated at the post-translational level by several factors that are associated with both physiological and pathological functions. Since the discovery of BACE1 over a decade ago, medicinal chemistry and pharmacokinetics of BACE1 small molecule inhibitors have proven challenging for the treatment of Alzheimer's disease.