Discovery of Potent Cholinesterase Inhibition-Based Multi-Target-Directed Lead Compounds for Synaptoprotection in Alzheimer's Disease.

Drug development efforts that focused on single targets failed to provide effective treatment for Alzheimer's disease (AD). Therefore, we designed cholinesterase inhibition (ChEI)-based multi-target-directed ligands (MTDLs) to simultaneously target AD-related receptors. We built a library of 70 compounds, sequentially screened for ChEI, and determined σ1R, σ2R, NMDAR-GluN2B binding affinities, and P2X7R antagonistic activities. Nine fulfilled in silico drug-likeness criteria and did not display toxicity in three cell lines. Seven displayed cytoprotective activity in two stress-induced cellular models. Compared to donepezil, six showed equal/better synaptic protection in a zebrafish model of acute amyloidosis-induced synaptic degeneration. Two P2X7R antagonists alleviated the activation state of microglia in vivo. Permeability studies were performed, and four did not inhibit CYP450 3A4, 2D6, and 2C9. Therefore, four ChEI-based lead MTDLs are promising drug candidates for synaptic integrity protection and could serve as disease-modifying AD treatment. Our study also proposes zebrafish as a useful preclinical tool for drug discovery and development.

Lead Optimization and Structure-Activity Relationship Studies on Myeloid Ecotropic Viral Integration Site 1 Inhibitor.

The pivotal role of the myeloid ecotropic viral integration site 1 (MEIS1) transcriptional factor was reported in cardiac regeneration and hematopoietic stem-cell (HSC) regulation with our previous findings. MEIS1 as a promising target in the context of pharmacological inhibition, we identified a potent myeloid ecotropic viral integration site (MEIS) inhibitor, MEISi-1, to induce murine and human HSC expansion ex vivo and in vivo. In this work, we performed lead optimization on MEISi-1 by synthesizing 45 novel analogues. Structure-activity relationship studies revealed the significance of a para-methoxy group on ring A and a hydrophobic moiety at the meta position of ring B. Obtained biological data were supported by inhibitor docking and molecular dynamics simulation studies. Eleven compounds were depicted as potent inhibitors demonstrating a better inhibitory profile on MEIS1 and target genes Meis1, Hif-1α, and p21. Among those, 4h, 4f, and 4b were the most potent inhibitors. The predicted pharmacokinetics properties fulfill drug-likeness criteria. In addition, compounds exerted neither cytotoxicity on human dermal fibroblasts nor mutagenicity.

Design, synthesis, and biological evaluation of new urolithin amides as multitarget agents against Alzheimer's disease.

A series of urolithin amide (i.e., URO-4-URO-10 and THU-4-THU-10) derivatives was designed and synthesized, and their chemical structures were confirmed with spectroscopic techniques and elemental analysis. The title compounds and synthesis intermediates (THU-1-THU-10 and URO-1-URO-10) were evaluated for their potential to inhibit acetylcholinesterase (AChE), butyrylcholinesterase (BuChE), and monoamine oxidase B (MAO-B). Compounds THU-4 and THU-8 were found to be the most potent inhibitors for the cholinesterases and MAO-B, respectively. The docking studies were also employed to evaluate the binding modes of the most active compounds with AChE, BuChE, and MAO-B. Furthermore, the moderate-to-strong activities of the compounds were also displayed in amyloid-beta inhibition and antioxidant assay systems. The results pointed out that the urolithin scaffold can be employed in drug design studies for the development of multitarget ligands acting on various cascades shown to be important within the pathophysiology of Alzheimer's disease.

Synthesis, Antimicrobial, Antioxidant and Molecular Docking Studies on Novel 6-Methoxybenzothiazole-piperazine Derivatives with Propanamide Chain.

BACKGROUND: Infectious diseases are a major threat in the developing world and the discovery of novel antimicrobial agents remains to be crucial due to acquired resistance by the microorganisms. Additionally, various diseases can be prevented with antioxidant agents as they can eliminate the harmful effects of reactive oxygen species. OBJECTIVE: In this study, it was aimed to synthesize novel compounds bearing N-(6- methoxybenzothiazol-2-yl)-3-(4-substitued piperazinyl)propanamide backbone that had antimicrobial and antioxidant activities. Mechanisms of activity were aimed to be revealed by docking studies. METHODS: Antimicrobial activities were tested by agar-based disc diffusion assay, and antioxidant activities were determined by CUPRAC assay. RESULTS: In agar-based disc diffusion assay, the most active compounds were 2b and 2e against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Candida albicans. Compounds 2e and 2j showed promising antioxidant activity in CUPRAC assay. Docking studies were performed to optimize the interactions of compounds with DNA gyrase subunit B of S. aureus. Under the light of docking studies, a new compound with potential GyrB inhibition was designed. Antioxidant activity was also supported by docking studies on superoxide dismutase 1 enzyme in which interactions with key residues were observed. CONCLUSION: Ten novel benzothiazole-piperazine derivatives were synthesized and their antimicrobial and antioxidant activities were evaluated. Superoxide dismutase 1 enzyme was suggested to be a possible target for the antioxidant activity of the series.

Synthesis of Novel Benzothiazole-Piperazine Derivatives and Their Biological Evaluation as Acetylcholinesterase Inhibitors and Cytotoxic Agents.

OBJECTIVE AND METHOD: A new series of benzothiazole-piperazine derivatives was synthesized and a complete chemical characterization of the novel compounds was provided. In vitro cytotoxic activities were screened against colorectal (HCT-116), breast (MCF-7) and hepatocellular (Huh7) cancer cell lines by Sulforhodamine B assay. RESULT AND DISCUSSION: All compounds showed cytotoxic activity against hepatocellular (Huh7) and breast (MCF-7) cancer cell lines. Dihalo substituted benzylpiperazine derivatives (2a, 2e) had the highest cytotoxic activities in all the tested cell lines. In addition, acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory activities of synthesized compounds were investigated by in vitro Ellman's method. Compound 2j led to moderate and selective inhibition against AChE. Docking study was utilized to understand the binding mode of compound 2j in comparision with donepezil on AChE. The other tested compounds showed weak or no inhibition against AChE as promising anticancer agents.

Synthesis and anticancer activity evaluation of some benzothiazole-piperazine derivatives.

Synthesis, characterization and cytotoxic activities of ten benzothiazole-piperazine derivatives were reported. In vitro cytotoxic activities of compounds were screened against hepatocellular (HUH-7), breast (MCF-7) and colorectal (HCT-116) cancer cell lines by sulphorhodamine B assay. Based on the GI50 values of the compounds, most of the benzothiazole-piperazine derivatives are active against HUH-7, MCF-7 and HCT-116 cancer cell lines. Aroyl substituted compounds 1h and 1j were found to be the most active derivatives. In addition, further investigation of compounds 1h and 1j by Hoechst staining and FACS revealed that these compounds cause apoptosis by cell cycle arrest at subG1 phase.

Cytotoxic activities of some benzothiazole-piperazine derivatives.

Synthesis, characterization and cytotoxic activities of ten benzothiazole-piperazine derivatives were reported. In vitro cytotoxic activities of compounds were screened against hepatocellular (HUH-7), breast (MCF-7) and colorectal (HCT-116) cancer cell lines by sulphorhodamine B assay. Based on the GI50 values of the compounds, most of the benzothiazole-piperazine derivatives are active against HUH-7, MCF-7 and HCT-116 cancer cell lines. Compound 1d is highly cytotoxic against all tested cancer cell lines. Further investigation of compound 1d by Hoechst Staining and Fluorescence-Activated Cell Sorting Analysis (FACS) revealed that this compound causes apoptosis by cell cycle arrest at subG1 phase.

Synthesis and cytotoxicity studies of novel benzhydrylpiperazine carboxamide and thioamide derivatives.

Synthesis and cytotoxic activities of 32 benzhydrylpiperazine derivatives with carboxamide and thioamide moieties were reported. In vitro cytotoxic activities of compounds were screened against hepatocellular (HUH-7), breast (MCF-7) and colorectal (HCT-116) cancer cell lines by sulphorhodamine B assay. In general, 4-chlorobenzhydrylpiperazine derivatives were more cytotoxic than other compounds. In addition, thioamide derivatives (6a-g) have higher growth inhibition than their carboxamide analogs.

Cancer cell cytotoxicities of 1-(4-substitutedbenzoyl)-4-(4-chlorobenzhydryl)piperazine derivatives.

A series of novel 1-(4-substitutedbenzoyl)-4-(4-chlorobenzhydryl)piperazine derivatives 5a-g was designed by a nucleophilic substitution reaction of 1-(4-chlorobenzhydryl)piperazine with various benzoyl chlorides and characterized by elemental analyses, IR and (1)H nuclear magnetic resonance spectra. Cytotoxicity of the compounds was demonstrated on cancer cell lines from liver (HUH7, FOCUS, MAHLAVU, HEPG2, HEP3B), breast (MCF7, BT20, T47D, CAMA-1), colon (HCT-116), gastric (KATO-3) and endometrial (MFE-296) cancer cell lines. Time-dependent cytotoxicity analysis of compound 5a indicated the long-term in situ stability of this compound. All compounds showed significant cell growth inhibitory activity on the selected cancer cell lines.

Synthesis and in vitro Evaluation of Novel Indole-Based Sigma Receptors Ligands.

To investigate the molecular features involved in sigma (σ) receptors binding, a series of compounds based on indole scaffolds were synthesized and their chemical structures were confirmed by (1) H-NMR, IR, and elemental analysis. Their affinity toward σ(1) and σ(2) receptor subtypes was evaluated. 1-{[4-(2-phenylethyl)piperazin-1-yl]methyl}-3-methyl-1H-indole 3b had a high affinity to σ(1) receptors, while three compounds, 1-{3-[4-(substitutedphenyl)piperazin-1-yl]propyl}-1H-indole derivatives 4a-c had shown high affinity and selectivity for σ(2) receptors. Cytotoxicity of the compounds was demonstrated on cancer cell lines from liver (HUH7), breast (MCF7), and colon (HCT-116) cancer cell lines. Compound 1c (3-{[4-(3,4-dichlorobenzyl)piperazin-1-yl]methyl}-1H-indole) showed significant cell growth inhibitory activity on the selected cancer cell lines.

Application of QSAR analysis to organic anion transporting polypeptide 1a5 (Oatp1a5) substrates.

Organic anion transporting polypeptide 1a5, Slco1a5 (previously called Oatp3, Slc21a7) is a multispecific transmembrane transport protein that belongs to the OATP/SLCO superfamily of solute carriers. It is expressed in several epithelial barriers such as the small intestine and the choroid plexus where it might play an important role in the disposition of numerous endogenous and exogenous organic compounds. Since the molecular basis of the multispecificity of Oatp1a5 is not known and the three-dimensional structure not solved yet, we used three-dimensional quantitative structure-activity relationship (3D-QSAR) techniques to obtain topological information on the substrate binding site of the protein. We aligned a heterogeneous data set of 18 Oatp1a5 substrates using the Genetic Algorithm Similarity Program (GASP) and performed comparative molecular field analysis (CoMFA) using this alignment. This resulted in a reasonable QSAR model including steric and electrostatic fields with a leave-one-out cross-validated r(cv)2 value of 0.705 and a no-cross-validated regression coefficient r2 value of 0.949. Based on the derived model we identified new potential Oatp1a5 substrates and confirmed their predicted apparent affinity values experimentally.

Synthesis and in vitro calcium antagonist activity of 4-aryl-7,7-dimethyl/1,7,7-trimethyl-1,2,3,4,5,6,7,8-octahydroquinazoline-2,5-dione derivatives.

In this study, a series of 4-aryl-7,7-dimethyl and 1,7,7-trimethyl-1,2,3,4,5,6,7,8-octahydroquinazoline-2,5-diones (1-25) were synthesized by condensing urea or N-methylurea with 5,5-dimethyl-1,3-cyclohexanedione and appropriate aromatic aldehydes according to the Biginelli reaction. The structures of the compounds were confirmed by spectral data and elementary analysis. The calcium antagonist activity of the compounds was tested in vitro on isolated rat ileum and lamb carotid artery. Compounds 16 and 19 were the most active derivatives on isolated rat ileum compared with the standard nicardipine. On isolated aortic strips of lamb the calcium antagonist activity of compound 16 (maximum relaxant effect: 38.83+/-5.84%) was found as high as that of nicardipine (maximum relaxant effect: 35.50+/-4.16%) used as a reference drug.

Synthesis and antimicrobial activity evaluation of some new adamantane derivatives.

In this study, some new Schiff bases were synthesized as antimicrobial agents using benzaldehyde derivatives and 1- or 2-aminoadamantane. The structures of the synthesized compounds were confirmed by IR, 1H-NMR and elementary analysis. Antimicrobial activities of the synthesized compounds were tested against some bacteria and yeast-like fungi. The antimicrobial activity of the compounds was investigated by broth microdilution method using two Gram positive (Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212) and two Gram negative (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853) bacteria and yeast-like fungi (Candida albicans ATCC 90028, Candida krusei ATCC 6258, Candida parapsilosis ATCC 22019). The antifungal activity of 1-((2-chloro-3,4-dimethoxybenzylidene) amino(adamantane (compound 3) against C. krusei and C. parapsilosis (minimal inhibitory concentration 32 micrograms/ml) was higher than that of the other tested compounds.

Synthesis, enantioseparation and pharmacological activity of 4-aryl-7,7-dimethyl-5-oxo-1,2,3,4,5,6,7,8-octahydroquinazoline-2-thiones.

4-Aryl-7,7-dimethyl-5-oxo-1,2,3,4,5,6,7,8-octahydroquinazoline-2-thione derivatives (1-8) have been prepared by modified Biginelli reaction from 5,5-dimethyl-1,3-cyclohexanedione, the aromatic aldehydes and thiourea. The structures of the compounds were confirmed by spectroscopic and elemental analysis. Racemic compounds were resolved into their enantiomers by HPLC using an amylose tris-(3,5-dimethylphenylcarbamate) chiral stationary phase in the normal phase mode. The calcium antagonist activities of the compounds were determined by the tests performed on isolated rat ileum and lamb carotid artery. Compounds 2, 3, 4 and 6 were the most active compounds on isolated rat ileum. Compounds 2 and 3 were significantly active on lamb carotid artery.