Development of new benzil-hydrazone derivatives as anticholinesterase inhibitors: synthesis, X-ray analysis, DFT study and in vitro/in silico evaluation.

Alzheimer's disease (AD) is a complex neurodegenerative disorder affecting the central nervous system. Current drugs for AD have limited effectiveness and often come with side effects. Consequently, there is a pressing need to develop new, safe, and more effective treatments for Alzheimer's disease. In this work, two novel benzil-hydrazone compounds, abbreviated 2-ClMHB and 2-ClBHB, were synthesized for the first time by refluxing the benzil with 2-Chloro phenyl hydrazine and they have been tested for their in vitro anti-cholinesterase activities and in silico acetyl and butyryl enzymes inhibition. The resulting products were characterized using UV-Vis and IR spectroscopy, while the single-crystal X-ray diffraction investigation was successful in establishing the structures of these compounds. DFT calculations have been successfully made to correlate the experimental data. According to biological studies, the synthesized hydrazones significantly inhibited both butyrylcholinesterase (2-ClMHB: 20.95 ± 1.29 µM and 2-ClBHB: 31.21 ± 1.50 µM) and acetylcholinesterase (2-ClMHB: 21.80 ± 1.10 µM and 2-ClBHB: 10.38 ± 1.27 µM). Moreover, molecular docking was also employed to locate the molecule with the optimum interaction and stability as well as to explain the experimental findings. The compound's dynamic nature, binding interaction, and protein-ligand stability were investigated using molecular dynamics (MD) simulations. Analyzing parameters such as RMSD and RMSF indicated that the compound remained stable throughout the 100 ns MD simulation. Finally, the drugs displayed high oral bioavailability, as per projected ADME and pharmacokinetic parameters.Communicated by Ramaswamy H. Sarma.

Chalcone-based imidazo[2,1-b]thiazole derivatives: synthesis, crystal structure, potent anticancer activity, and computational studies.

In this work, two novel chalcone-based imidazothiazole derivatives ITC-1 and ITC-2 were synthesized and characterized by 1H NMR, 13C NMR and high-resolution mass spectrometry with electrospray ionization, and chemical structure of ITC-1 was confirmed by single-crystal X-ray diffraction. Also, the anticancer activity of ITC-1 and ITC-2 was evaluated. First, antiproliferative activity tests were performed against cancer cells namely, human-derived breast adenocarcinoma (MCF-7), lung carcinoma (A-549), and colorectal adenocarcinoma (HT-29) cell lines, and mouse fibroblast healthy cell line (3T3-L1) by XTT assay. Afterward, mitochondrial membrane disruption (MMP), caspase activity, and apoptosis tests were performed on MCF-7 cells to elucidate the anticancer mechanism of action of the test compounds by flow cytometry analysis. XTT results revealed that both compounds exhibited a very high degree of antiproliferative effects on each tested cancer cell line with very low IC50 values while showing much lower antiproliferation on 3T3-L1 normal cells with much higher IC50 values. Besides, ITC-2 was determined to have a striking cytotoxic power competing with the chemotherapeutic drug carboplatin. Flow cytometry results demonstrated the mitochondrial-mediated apoptotic effects of both compounds through membrane disruption and multi-caspase activation in MCF-7 cells. Finally, molecular docking studies were performed to determine the structural understanding of the test compounds by their interactions on caspase-3 and DNA dodecamer enzymes, respectively. The interactions between the compound and the crystal structure were determined according to parameters such as free binding energies (ΔGBind), Glide score values, and determination of the active binding site. The obtained data suggest that ITC-1 and ITC-2 may be considered remarkable anticancer drug candidates. In addition to molecular docking via in silico approaches, the pharmacokinetic properties of compounds ITC-1 and ITC-2 were calculated using the Schrödinger 2021-2 Qikprop wizard.Communicated by Ramaswamy H. Sarma.

Bifunctional Cu(II)-based 2D coordination polymer and its composite for high-performance photocatalysis and electrochemical energy storage.

Coordination polymers (CPs) have been widely proven as sacrificial electrode materials for energy storage applications because of their high porosity, specific surface area and tunable structural topology. In this work, a new 2D Cu(II)-based CP, formulated as [Cu2(btc)(µ-Cl)2(H2O)4]n (CP-1) (H3btc = benzene-1,3,5-tricarboxylic acid), fabrication of copper oxide nanoparticles (CuO NPs) and its composite (CuO@CP-1) were successfully synthesized using solvothermal, precipitation and mechanochemical grinding approaches. Single-crystal X-ray analysis authenticated a two-dimensional (2D) layered network of CP-1. Further, CP-1, CuO NPs and composite were characterized by diffraction (Powder-XRD), spectroscopic (FTIR), microscopic (SEM), and thermal (TGA) techniques. The porosity and surface behavior of CP-1 and the composite were demonstrated using BET analyzer. Topological simplification of CP-1 shows a 3-c connected hcb periodic net. The photocatalytic behavior of CP-1 was examined over methyl red (MR) dye in the presence of sunlight and showed a promising degradation efficiency of 96.80%. The electrochemical energy storage properties of CP-1, CuO NPs and composite were investigated using cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) analysis under aqueous 1 M H2SO4 electrolyte. The electrochemical results show better charge storage performance of CP-1 with a specific capacitance of 602.25 F g-1 at 1 A g-1 current density by maintaining a retention of up to 84.51% after 5000 cycles at 10 A g-1 current density. Comparative electrochemical studies reveal that CP-1 is a promising electrode material for energy storage.

Experimental and Theoretical Biological Probing of Schiff Bases as Esterase Inhibitors: Structural, Spectral and Molecular Insights.

The present study was designed to evaluate the in vitro and in silico potential of the Schiff bases (Z)-4-ethoxy-N-((5-nitrothiophen-2-yl)methylene)benzenamine (1) and (Z)-2,4-diiodo-6-((2-methyl-3-nitrophenylimino)methyl)phenol (2). These Schiff bases were synthesized according to a reported method using ethanol as a solvent, and each reaction was monitored on a TLC until completion of the reaction. The structures of both compounds were elucidated using spectroscopic techniques such as UV-Vis, FTIR, 1H NMR and 13C NMR. Molecular structure was determined using single-crystal XRD, which revealed that compounds 1 and 2 were monoclinic and triclinic, respectively. Hirshfeld surface analysis (HS) and 2D fingerprint plots were used to determine the intermolecular interactions along the contact contribution in the crystalline molecules. The structures of both compounds were optimized through a hybrid functional method B3LYP using the 6-31G(d,p) basis set, and various structural parameters were studied. The experimental and theoretical parameters (bond angle and bond length) of the compounds were compared with each other and are in close agreement. The in vitro esterase potential of the synthesized compounds was checked using a spectrophotometric model, while in silico molecular docking studies were performed with AutoDock against two enzymes of the esterase family. The docking studies and the in vitro assessment predicted that such molecules could be used as enzyme inhibitors against the tested enzymes: acetylcholine esterase (AChE) and butyrylcholine esterase (BChE).

Computational modeling of imines based anti-oxidant and anti-esterases compounds: Synthesis, single crystal and In-vitro assessment.

Molecular modeling strategy was adopted to check the biological potential of the imine based molecules against free radical, acetylcholine esterase and butyrylcholine esterase. Three Schiff based compounds as (E)-2-(((4-bromophenyl)imino)methyl)-4-methylphenol (1), (E)-2-(((3-fluorophenyl)imino)methyl)-4-methylphenol (2) and (2E,2E)-2-(2-(2-hydroxy-5-methylbenzylidene)hydrazono)-1,2-diphenylethanone (3) were synthesized with high yield. The synthesized compounds were characterized with the help of modern techniques such as UV, FTIR and NMR while exact structure was depicted with Single Crystal X-Ray diffraction technique which disclosed that compound 1 is orthorhombic, while 2 and 3 are monoclinic. A hybrid functional (B3LYP) method with general basis set of 6-31 G(d,p) were applied to optimize synthesized Schiff bases. The contribution of in-between molecular contacts within a crystalline assembly of compounds were studied using Hirshfeld surface analysis (HS). In order to check the ability of the synthesized compounds toward free radical and enzyme inhibition, in vitro models were used to assess the radical scavenging and enzyme inhibition potential which depicted that compound 3 showed highest potential (57.43 ± 1.0%; DPPH, 75.09 ± 1.0%; AChE and 64.47 ± 1.0%; BChE). The ADMET assessments suggested the drug like properties of the synthesized compounds. It was concluded from results (in vitro and in silico) that synthesized compound have ability to cure the disorder related to free radical and enzyme inhibition. Compound 3 was shown to be the most active compared to other compounds.

Crystal structure, Hirshfeld surface analysis and DFT study of (5E,5'E,6Z,6'Z)-6,6'-[ethane-1,2-diyl-bis(aza-nylyl-idene)]bis-{5-[2-(4-fluoro-phen-yl)hydra-zono]-3,3-di-methyl-cyclo-hexa-none} 2.5-hydrate.

The title compound, C30H34F2N6O2·2.5H2O, was obtained by condensation of 2-[2-(4-fluoro-phen-yl)hydrazono]-5,5-di-methyl-cyclo-hexan-1,3-dione with ethyl-enedi-amine in ethanol and crystallized as a 1:2.5 hydrate in space group C2/c. The two independent mol-ecules, with approximate crystallographic C 2 symmetries, have different conformations and packing environments, are stabilized by intra-molecular N-H⋯N hydrogen bonds and linked by O-H⋯O hydrogen bonds involving the water mol-ecules. A Hirshfeld surface analysis showed that H⋯H contacts make by far the largest (48-50%) contribution to the crystal packing. From DFT calculations, the LUMO-HOMO energy gap of the mol-ecule is 0.827 eV.

Synthesis, crystal structure, DFT, Hirshfeld surface analysis, energy framework, docking and molecular dynamic simulations of (E)-4-(4-methylbenzyl)-6-styrylpyridazin-3(2H)-one as anticancer agent.

In this work, a novel crystal, (E)-4-(4-methylbenzyl)-6-styrylpyridazin-3(2H)-one (E-BSP) was synthesized via Knoevenagel condensation of benzaldehyde and (E)-6-(4-methoxystyryl)-4,5-dihydropyridazin-3(2H)-one. The molecular structure of E-BSP was confirmed by using FT-IR, 1H-NMR, 13C-NMR, UV-vis, ESI-MS, TGA/DTA thermal analyses and single crystal X-ray diffraction. The DFT/B3LYP methods with the 6-311++G(d,p) basis set were used to determine the vibrational modes over the optimized structure. Potential energy distribution (PED) and the VEDA 4 software were used to establish the theoretical mode assignments. The same approach was used to compute the energies of frontier molecular orbitals (HOMO-LUMO), global reactivity descriptors, and molecular electrostatic potential (MEP). Additionally, experimental and computed UV spectral parameters were determined in methanol and the obtained outputs were supported by FMO analysis. Molecular docking and molecular dynamics (MD) simulation analyses of the E-BSP against six proteins obtained from different cancer pathways were carried out. The proteins include; epidermal growth factor receptor (EGFR), Estrogen receptor (ERα), Mammalian target of rapamycin (mTOR), Progesterone receptor (PR) (Breast cancer), Human cyclin-dependent kinase 2 (CDK2) (Colorectal cancer), and Survivin (Squamous cell carcinoma/Non-small cell lung cancer). The results of the analyses showed that the compound had less binding energies ranging between -6.30 to -9.09 kcal/mol and formed stable complexes at the substrate-binding site of the proteins after the 50 ns MD simulation. Therefore, E-BSP was considered a potential inhibitor of different cancer pathways and should be used for the treatment of cancer after experimental validation and clinical trial.Communicated by Ramaswamy H. Sarma.

Crystal structure and Hirshfeld surface analysis of 2,4,6-tri-amino-pyrimidine-1,3-diium dinitrate.

The title compound, C4H9N5 2+·2NO3 -, crystallizes in the monoclinic crystal system, space group P21/c. The asymmetric unit, which comprises a diprotonated tri-amino-pyrimidine dication and two nitrate anions, has an almost planar geometry with a dihedral angle of 0.92 (4)° between the mean plane of the cation and that defined by both anions. In the crystal, hydrogen-bonding inter-actions between the 2,4,6-tri-amino-pyrimidine cation and the nitrate anions lead to a one-dimensional supra-molecular network with weak anionic inter-actions forming a three-dimensional network. These inter-actions were investigated using Hirshfeld surface analysis, which indicates that the most important contributions for the packing arrangement are from O⋯H/H⋯O (53.2%), N⋯H/H⋯N (12.5%) and C⋯H/H⋯C (9.6%) inter-actions. Energy framework analysis showed that of the components of the framework energies, electrostatic repulsion (E rep) is dominant.

New Organic-Inorganic Salt Based on Fluconazole Drug: TD-DFT Benchmark and Computational Insights into Halogen Substitution.

In this study, we report the synthesis of a new organic-inorganic molecular salt of the clinically used antifungal drug fluconazole, (H2Fluconazole).SnCl6.2H2O. By detailed investigation and analysis of its structural properties, we show that the structure represents a 0D structure built of alternating organic and inorganic zig-zag layers along the crystallographic c-axis and the primary supramolecular synthons in this salt are hydrogen bonding, F···π and halogen bonding interactions. Magnetic measurements reveal the co-existence of weak ferromagnetic behavior at low magnetic field and large diamagnetic contributions, indicating that the synthesized material behaves mainly as a diamagnetic material, with very low magnetic susceptibility and with a band gap energy of 3.6 eV, and the salt is suitable for semiconducting applications. Extensive theoretical study is performed to explain the acceptor donor reactivity of this compound and to predict the Cl-substitution effect by F, Br and I. The energy gap, frontier molecular orbitals (FMOs) and the different chemical reactivity descriptors were evaluated at a high theoretical level. Calculations show that Cl substitution by Br and I generates compounds with more important antioxidant ability and the intramolecular charge transfer linked to the inorganic anion.

Synthesis of 3-Methoxy-6- [(2, 4, 6-trimethyl-phenylamino)-methyl]-phenol Schiff base characterized by spectral, in-silco and in-vitro studies.

The structure of the title compound (I) (C17H19NO2)2 the Schiff base, {3-Methoxy-6-[(2,4,6-trimethyl-phenylamino)-methyl]-phenol} was characterized by 1H, 13C NMR, UV-VIS and IR spectroscopic techniques. The crystal structure was determined by X-ray analysis. The compound (I) was crystallized in the Monoclinic space group P21/c, with a = 25.9845 (12), b = 7.3318 (4), c = 16.3543 (8) Å, ß = 100.713(°) (4), and Z = 8. The intermolecular interactions of the compound (I) was analyzed using Hirshfeld surface and Fingerprint analysis. Based on the crystal-void calculation, the volume of the void and surface area of the Schiff base compound (I) was described. The frontier molecular orbital energy gap reveals charge transfer interactions involving donors and acceptors. The invitro studies on antibacterial property of the title compound shows best MIC value for Staphylococcus aureus and the compound effect on MTT assay on A549 lung cancer cell line. The molecular docking result shows that the compound has good molecular-level interaction with anticancer drug target having good interactions with active site residues. The non-covalent interactions in the protein-ligand complex were well established from NCI analysis.

Synthesis, Structure and Biological Evaluations of Zn(II) Pincer Complexes Based on S-Triazine Type Chelator.

2,4-bis (3,5-dimethyl-1H-pyrazol-1-yl)-6-methoxy-1,3,5-triazine (BPMT) pincer ligand was used to synthesize the new [Zn(BPMT)(NCS)2] (1) and [Zn(BPMT)(Br)2] (2) complexes by a reaction with Zn(NO3)2·6H2O in the presence of either KSCN or KBr, respectively. The structure of complex 1 has been exclusively confirmed using single crystal X-ray diffraction. In this neutral heteroleptic complex, the BPMT is a pincer chelate coordinating the Zn(II) ion via three interactions with the two pyrazole moieties and the s-triazine core. Hence, BPMT is a tridentate NNN-chelate. The coordination environment of Zn(II) is completed by two strong interactions with two terminal SCN- ions via the N-atom. Hence, the Zn(II) is penta-coordinated with a distorted square pyramidal coordination geometry. Hirshfeld analysis indicated the predominance of H…H, H…C and N…H intermolecular interactions. Additionally, the S…H, S…C and S…N contacts are the most significant. The free ligand has no or weak antimicrobial, antioxidant and anticancer activities while the studied Zn(II) complexes showed interesting biological activity. Complex 1 has excellent antibacterial activity against B. subtilis (2.4 µg/mL) and P. vulgaris (4.8 µg/mL) compared to Gentamycin (4.8 µg/mL). Additionally, complex 1 (78.09 ± 4.23 µg/mL) has better antioxidant activity than 2 (365.60 ± 20.89 µg/mL). In addition, complex 1 (43.86 ± 3.12 µg/mL) and 2 (30.23 ± 1.26 µg/mL) have 8 and 12 times the anticancer activity of the free BPMT ligand (372.79 ± 13.64 µg/mL).

Crystal structure and Hirshfeld surface analysis of dimethyl 3,3'-{[(1E,2E)-ethane-1,2-diyl-idene]bis(aza-nylyl-idene)}bis-(4-methyl-benzoate).

The title Schiff base compound, C20H20N2O4, synthesized by the condensation reaction of methyl 3-amino-4-methyl-benzoat and glyoxal in ethanol, crystallizes in the the monoclinic space group P21/n. The mol-ecule is Z-shaped with the C-N-C-C torsion angle being 47.58 (18)°. In the crystal, pairs of mol-ecules are linked via C-H⋯N hydrogen bonds, forming centrosymetric dimers with an R 2 2(8) ring motif; this connectivity leads to the formation of columns running along the a-axis direction. Hirshfeld surface analysis and two-dimensional fingerprint plots were used to explore the inter-molecular inter-actions and revealed that the most significant contributions to the crystal packing are from H⋯H (49.4%), H⋯O/O⋯H (19.0%) and H⋯C/C⋯H (17.5%) contacts. Energy frameworks were constructed through different inter-molecular inter-action energies to investigate the stability of the compound. The net inter-action energies for the title compound were found to be electrostatic (E ele = -48.4 kJ mol-1), polarization (E pol = -9.7 kJ mol-1), dispersion (E dis = -186.9 kJ mol-1) and repulsion (E rep = 94.9 kJ mol-1) with a total inter-action energy, E tot, of -162.4 kJ mol-1.

Crystal structure of (E)-3-({6-[2-(4-chloro-phen-yl)ethen-yl]-3-oxo-2,3-di-hydro-pyridazin-4-yl}meth-yl)pyridin-1-ium chloride dihydrate.

In the title compound, C18H15ClN3O+·Cl-·2H2O, three intra-mol-ecular hydrogen bonds are observed, N-H⋯O, O-H⋯Cl and O-H⋯O. In the crystal, mol-ecules are connected by C-H⋯Cl and N-H⋯O hydrogen bonds. Strong C-H⋯Cl, N-H⋯O, O-H⋯Cl and O-H⋯O hydrogen-bonding inter-actions are implied by the Hirshfeld surface analysis, which indicate that H⋯H contacts make the largest contribution to the overall crystal packing at 33.0%.

Therapeutical Potential of Imines; Synthesis, Single Crystal Structure, Computational, Molecular Modeling, and ADMET Evaluation.

Imines are multipurpose pharmacophores, simply accessible compounds, and have a broad range of usage in several areas of chemistry especially in medicine. Two novel compound imines, (E)-4-methyl-2-((o-tolylimino)methyl)phenol (1) and (E)-2-(((4-methoxybenzyl)imino)methyl)-4-methylphenol (2), were synthesized with effective product via reported protocol in the literature. Single crystal X-ray diffraction (SCXRD) was employed for structural exposition, disclosing that both compounds are orthorhombic. To optimize the newly designed imines, a B3LYP functional with a basis set 6-31G(d,p) was mainly considered. DFT results were utilized to check correlation between the data recovered from SCXRD outcomes and also to measure the energy difference. Hirshfeld surface study was done to demonstrate the intermolecular contacts along the percentage of interaction in the overall crystalline compound. Molecular operating environment program was tested against AChE and BChE enzymes to perform a modeling study of the compounds. The docking score and binding affinity of the compounds revealed that 2 showed comparatively more inhibition than 1. In silico ADMET studies exposed the physiochemical nature of these novel compounds, and it also unveiled that both compounds behaved as drug-like candidates.

Synthesis, solid state self-assembly driven by antiparallel π⋯π stacking and {⋯H-C-C-F}2 dimer synthons, and in vitro acetyl cholinesterase inhibition activity of phenoxy pendant isatins.

A series of novel phenoxy pendant isatins PI1-12 have been synthesized in excellent yields by a simple nucleophilic substitution reaction involving isatins and 1-(2-bromoethoxy)-4-substituted benzenes, and characterized by their FT-IR, 1H NMR, 13C NMR and GC-MS data, and in the case of PI4 by its single crystal X-ray analysis. The solid-state structure of PI4 showed an intriguing and unique 1D-supramolecular chain-based self-assembled structure, the driving force of which is mainly the strong antiparallel π⋯π stacking and {⋯H-C-C-F}2 dimer synthons. This compound not only highlights the potential of the isatin moiety in forming strong antiparallel π⋯π stacking interactions but also provides a platform to have considerable insight into the nature, strength and directionality of much debated π-π and C-H⋯F-C interactions. The in vitro biological studies revealed that three phenoxy pendant isatins PI1, PI2 and PI4 are highly potent inhibitors of acetylcholinesterase enzyme with IC50 values of 0.52 ± 0.073 µg ml-1, 0.72 ± 0.012 µg ml-1 and 0.68 ± 0.011 µg ml-1, respectively, showing comparable activity to the standard drug, donepezil (IC50 = 0.73 ± 0.015 µg ml-1). A simple and efficient synthesis of phenoxy pendant isatins PI1-12 from inexpensive and commercially available starting materials, and their high potential of acetyl cholinesterase inhibition provide an attractive opportunity to find more effective medication for Alzheimer's disease (AD).

Crystal structure and Hirshfeld surface analysis of 2-oxo-2-phenyl-ethyl 3-nitroso-2-phenyl-imidazo[1,2-a]pyridine-8-carboxyl-ate.

The title compound, C22H15N3O4, is built up from a central imidazo[1,2-a]pyridine ring system connected to a nitroso group, a phenyl ring and a 2-oxo-2-phenyl-ethyl acetate group. The imidazo[1,2-a] pyridine ring system is almost planar (r.m.s. deviation = 0.017 Å) and forms dihedral angles of 22.74 (5) and 45.37 (5)°, respectively, with the phenyl ring and the 2-oxo-2-phenyl-ethyl acetate group. In the crystal, the mol-ecules are linked into chains parallel to the b axis by C-H⋯O hydrogen bonds, generating R 2 1 (5) and R 4 4 (28) graph-set motifs. The chains are further linked into a three-dimensional network by C-H⋯π and π-stacking inter-actions. The inter-molecular inter-actions were investigated using Hirshfeld surface analysis and two-dimensional fingerprint plots, revealing that the most important contributions for the crystal packing are from H⋯H (36.2%), H⋯C/C⋯H (20.5%), H⋯O/O⋯H (20.0%), C⋯O/O⋯C (6.5%), C⋯N/N⋯C (6.2%), H⋯N/N⋯H (4.5%) and C⋯C (4.3%) inter-actions.

Growth, crystal structure, Hirshfeld surface analysis, DFT studies, physicochemical characterization, and cytotoxicity assays of novel organic triphosphate.

A novel organic-inorganic hybrid compound, named (1-phenylpiperazinium) trihydrogen triphosphate, with the formula (C10H15N2)2H3P3O10 has been obtained by low speed of evaporation of a mixture of an alcoholic solution of 1-phenylpiperazine and triphosphoric acid H5P3O10 at room temperature after using the ion exchange chemical procedure. To carry out a detailed crystallographic structure analysis, single-crystal X-ray diffraction has been reported. In the molecular arrangement, the different entities are held together through N-H…O, O-H…O, and C-H…O hydrogen bonds, building up a three-dimensional packing. Powder X-ray diffraction analysis is acquired to confirm the purity of the product. The nature and the proportion of intermolecular interactions were investigated by Hirshfeld surface analysis. In order to support the experimental results, a density functional theory (DFT) calculation was performed, using the Becke-3-parameter-Lee-Yang-Parr (B3LYP) function with LANL2DZ basis set, and the data indicate much agreement between the experimental and the theoretical results. Thus, the physicochemical properties were studied employing a variety of techniques (FTIR, NMR, UV-visible, and photoluminescence). To get an insight of the possible employment of the present material in biology, cell viability assays were performed.

Crystal structure and Hirshfeld surface analysis of (Z)-4-{[4-(3-methyl-3-phenyl-cyclo-but-yl)thia-zol-2-yl]amino}-4-oxobut-2-enoic acid.

The title cyclo-butyl compound, C18H18N2O3S, was synthesized by the inter-action of 4-(3-methyl-3-phenyl-cyclo-but-yl)thia-zol-2-amine and maleic anhydride, and crystallizes in the ortho-rhom-bic space group P212121 with Z' = 1. The mol-ecular geometry is partially stabilized by an intra-molecular N-H⋯O hydrogen bond forming an S 1 1(7) ring motif. The mol-ecule is non-planar with a dihedral angle of 88.29 (11)° between the thia-zole and benzene rings. In the crystal, the mol-ecules are linked by O-H⋯N hydrogen bonds, forming supra-molecular ribbons with C 1 1(9) chain motifs. To further analyze the inter-molecular inter-actions, a Hirshfeld surface analysis was performed. The results indicate that the most important contributions to the overall surface are from H⋯H (43%), C⋯H (18%), O⋯H (17%) and N⋯H (6%), inter-actions.

Synthesis, structure and acetylcholinesterase inhibition activity of new diarylpyrazoles.

A variety of diarylpyrazole derivatives III-VI were synthesized and structurally characterized using FTIR, 1H and 13C NMR spectroscopy, and in case of compound VIb by X-ray single crystal analysis. The in vitro biological studies revealed that seven of the diarylpyrazole derivatives IIIa, IIIb, IIId, IIIe, IVa, IVb and IVd are highly potent inhibitors of acetylcholinesterase enzyme with IC50 values of 0.48 ± 0.092 µg/mL, 0.45 ± 0.093 µg/mL, 0.30 ± 0.014 µg/mL, 0.59 ± 0.072 µg/mL, 0.29 ± 0.084 µg/mL, 0.56 ± 0.010 µg/mL and 0.28 ± 0.096 µg/mL, respectively. All these seven products were more potent than the standard drug, donepezil (IC50 = 0.73 ± 0.015 µg/mL), while compounds IIIc (0.67 ± 0.099 µg/ml) and VIa (0.66 ± 0.069 µg/ml) are almost equipotent to the donepezil. Particularly, compounds IVa and IVd are highly active acetylcholinesterase enzyme inhibitors, demonstrating more than two-fold inhibitory activity than the reference inhibitor. Molecular docking studies were carried out to identify the possible binding modes of the diarylpyrazoles within the active pocket of the enzymes. The docking interactions of the synthesized compounds with acetylcholinesterase also provided high docking scores. These results clearly indicate the potential of these compound as powerful lead molecules for further investigations.

Crystal structure and Hirshfeld surface analysis of 6-((E)-2-{4-[2-(4-chloro-phen-yl)-2-oxoeth-oxy]phen-yl}ethen-yl)-4,5-di-hydro-pyridazin-3(2H)-one.

The pyridazine ring in the title compound, C20H17ClN2O3, adopts a screw-boat conformation. The whole mol-ecule is flattened, the dihedral angles subtended by the least-squares plane of the central aromatic ring with those of the terminal benzene and pyridazine rings being 15.18 (19) and 11.23 (19)°, respectively. In the crystal, the mol-ecules are linked by pairs of N-H⋯O bonds into centrosymmetric dimers and by C-H⋯π contacts into columns. The results of the Hirshfeld surface analysis show that the most prominent inter-actions are H⋯H, accounting for 36.5% of overall crystal packing, and H⋯O/O⋯H (18.6% contribution) contacts.