Multifunctional cholinesterase inhibitors for Alzheimer's disease: Synthesis, biological evaluations, and docking studies of o/p-propoxyphenylsubstituted-1H-benzimidazole derivatives

This study indicates the synthesis, cholinesterase (ChE) inhibitory activity, and molecular modeling studies of 48 compounds as o- and p-(3-substitutedethoxyphenyl)-1H-benzimidazole derivatives. According to the ChE inhibitor activity results, generally, para series are more active against acetylcholinesterase (AChE) whereas ortho series are more active against butyrylcholinesterase (BuChE). The most active compounds against AChE and BuChE are compounds A12 and B14 with IC50 values of 0.14 and 0.22 μM, respectively. Additionally, the most active 16 compounds against AChE/BuChE were chosen to investigate the neuroprotective effects, and the results indicated that most of the compounds have free radical scavenging properties and show their effects by reducing free radical production; moreover, some of the compounds significantly increased the viability of SH-SY5Y cells exposed to H2 O2 . Overall, compounds A12 and B14 with potential AChE and BuChE inhibitory activities, high neuroprotection against H2 O2 -induced toxicity, free radical scavenging properties, and metal chelating abilities may be considered as lead molecules for the development of multi-target-directed ligands against Alzheimer's disease.

Covariance and sensitivity data generation at ORNL

Covariance data are required to assess uncertainties in design parameters in several nuclear applications. The error estimation of calculated quantities relies on the nuclear data uncertainty information available in the basic nuclear data libraries, such as the US Evaluated Nuclear Data Library, ENDF/B. The uncertainty files in the ENDF/B library are obtained from the analysis of experimental data and are stored as variance and covariance data. In this paper we address the generation of covariance data in the resonance region done with the computer code SAMMY. SAMMY is used in the evaluation of the experimental data in the resolved and unresolved resonance energy regions. The data fitting of cross sections is based on the generalised least-squares formalism (Bayesian theory) together with the resonance formalism described by R-matrix theory. Two approaches are used in SAMMY for the generation of resonance parameter covariance data. In the evaluation process SAMMY generates a set of resonance parameters that fit the data, and, it provides the resonance parameter covariances. For resonance parameter evaluations where there are no resonance parameter covariance data available, the alternative is to use an approach called the 'retroactive' resonance parameter covariance generation. In this paper, we describe the application of the retroactive covariance generation approach for the gadolinium isotopes.

Design, synthesis, acetylcholinesterase, butyrylcholinesterase, and amyloid-β aggregation inhibition studies of substituted 4,4'-diimine/4,4'-diazobiphenyl derivatives

A series of 4,4'-diimine/4,4'-diazobiphenyl derivatives were designed, synthesized, and evaluated for their ability to inhibit both the acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes, as well as Aβ_1-42 aggregation, in vitro. The AChE and BChE inhibition assays demonstrated that all compounds displayed moderate AChE inhibitory activity in the range of IC₅₀  = 5.77-16.22 μM, while they displayed weak or no BChE inhibition. Among the title compounds, compound 2l, 4,4'-bis(quinolin-8-yldiazenyl)-1,1'-biphenyl, having a diazo-quinoline moiety demonstrated the most potent inhibition against AChE with an IC₅₀ value of 5.77 μM. Furthermore, diazo derivatives 2d, 4,4'-bis[(4-methoxyphenyl)diazenyl]-1,1'-biphenyl, and 2i, 4,4'-bis(pyridin-3-yldiazenyl)-1,1'-biphenyl, provided better potency on Aβ_1-42 aggregation, with an inhibition value of 74.08% and 78.39% at 100 μM and 55.35% and 61.36% at 25 μM, respectively. Molecular modeling studies were carried out for the most active compound against AChE, compound 2l. All the results suggested that compounds 2d and 2i have better inhibitory potencies on Aβ_1-42 aggregation and moderate AChE enzyme activity, and therefore can be highlighted as promising compounds.