Synthesis, characterization, X-ray, α-glucosidase inhibition and molecular docking study of new triazolic systems based on 1,5-benzodiazepine via 1,3-dipolar cycloaddition reactions

We report in this work a synthesis of novel triazolo[1,5]benzodiazepine derivatives by the 1,3-dipolar cycloaddition reaction of N-aryl-C-ethoxycarbonylnitrilimines with 1,5-benzodiazepines. All the structures of the new compounds were determined from their NMR (1H and 13C) and HRMS. Then, X-ray crystallography analysis of compound 4d confirmed the stereochemistry of cycloadducts. The compounds 1, 4a-d, 5a-d, 6c, 7 and 8 were evaluated for their in vitro anti-diabetic activity against α-glucosidase. The compounds 1, 4d, 5a and 5b showed potential inhibitory activities compared to standard acarbose. Additionally, an in silico docking study was conducted to look into the active binding mode of the synthesized compounds within the target enzyme.Communicated by Ramaswamy H. Sarma.

Exploring the Efficacy of Benzimidazolone Derivative as Corrosion Inhibitors for Copper in a 3.5 wt.% NaCl Solution: A Comprehensive Experimental and Theoretical Investigation

This study focuses on the synthesis, theoretical analysis, and application of the corrosion inhibitor known as benzimidazolone, specifically 1-(cyclohex-1-enyl)-1,3-dihydro-2H-benzimiazol-2-one (CHBI). The structure of CHBI was determined by X-ray diffraction (XRD). The inhibitory properties of CHBI were investigated in a 3.5 wt.% NaCl solution on pure copper using various electrochemical techniques such as potentiodynamic polarization curves (PDPs) and electrochemical impedance spectroscopy (EIS), as well as scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), UV-visible spectroscopy, and theoretical calculations. The obtained results indicate that CHBI is an excellent inhibitor, exhibiting remarkable effectiveness with an inhibition rate of 86.49% at 10-3 M. To further confirm the extent of adsorption of the inhibitory molecule on the copper surface, density functional theory (DFT) and Monte Carlo (MC) simulation studies were conducted. The results of this study demonstrate the synthesis and characterization of CHBI as a corrosion inhibitor. The experimental and theoretical analyses provide valuable insights into the inhibitory performance of CHBI, indicating its strong adsorption on the copper surface.

Synthesis, Characterization, Antibacterial, Antifungal and Anticorrosion Activities of 1,2,4-Triazolo[1,5-a]quinazolinone

The synthesis of 5,6,7,8-tetrahydro-[1,2,4]triazolo[5,1-b]quinazolin-9(4H)-one (THTQ), a potentially biologically active compound, was pursued, and its structure was determined through a sequence of spectral analysis, including ¹H-NMR, ¹³C-NMR, IR, and HRMS. Four bacterial and four fungal strains were evaluated for their susceptibility to the antibacterial and antifungal properties of the THTQ compound using the well diffusion method. The impact of THTQ on the corrosion of mild steel in a 1 M HCl solution was evaluated using various methods such as weight loss, potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM) analysis. The study revealed that the effectiveness of THTQ as an inhibitor increased with the concentration but decreased with temperature. The PDP analysis suggested that THTQ acted as a mixed-type inhibitor, whereas the EIS data showed that it created a protective layer on the steel surface. This protective layer occurs due to the adsorption behavior of THTQ following Langmuir's adsorption isotherm. The inhibition potential of THTQ is also predicted theoretically using DFT at B3LYP and Monte Carlo simulation.

Synthesis, X-ray Crystal Structure, Anticancer, Hirshfeld Surface Analysis, DFT, TD-DFT, ADMET, and Molecular Docking of 3-Phenyl-1,2,4-triazolo[3,4-h]-13,4-thiaza-11-crown-4

In this work, we describe the synthesis of new macrocycles derived from 3-phenyl-1,2,4-triazole-5-thione 1 in a heterogeneous medium using liquid–solid phase transfer catalysis (PTC) conditions. The structures of the two compounds (3 and 4) isolated were elucidated based on spectral data (1H-NMR, 13C-NMR) and confirmed in the case of 3-phenyl-1,2,4-triazolo [3,4-h]-13,4--thiaza-11-crown-4 (3) by a single-crystal X-ray diffraction analysis. Furthermore, the experimental spectral and the X-ray geometrical parameters were compared with their corresponding predicted ones obtained at the B3LYP/6-311++G(d,p) level of theory. The intercontacts between crystal units were investigated through Hirshfeld surface analysis. The drug-like macrocycles were predicted using ADMET and drug-likeness properties, which showed that 3 may act as an inhibitor of DNA-dependent protein kinase (DNA-PK). This assumption was confirmed by the well-binding fitting of 3 into the binding site of DNA-PK and the formation of a stable 3-DNA-PK complex with a binding energy of −7 kcal-mol−1. Finally, the anticancer activity of 3 was assessed by an MTT assay against A549 cells, which showed that 3 has moderate anticancer activity compared to that of the doxorubicin reference drug.

Synthesis, structural characterization, antioxidant and antidiabetic activities, DFT calculation, and molecular docking of novel substituted phenolic and heterocyclic compounds

The current work describes the preparation of three unexpected compounds: a tetrasubstituted phenolic compound, an isocoumarin, and a pyranopyridine, bearing various substituent groups obtained through the condensation of 6-methyl-4-hydroxypyran-2-one 1 with 2-aminopyridine 2 under mild conditions. Plausible mechanisms explaining the formation of these compounds have been presented. Their structures have been elucidated using spectral data and confirmed by crystallographic studies. Furthermore, optimized geometries of and electronic distribution of FMOs orbitals are investigated in the PCM solvent model at the B3LYP/6-311++G(d,p) level of theory. The compounds were tested for their antioxidant and antidiabetic activities. Moreover, the binding interactions between the compounds and α-glucosidase and α-amylase were determined through their docking into the binding sites of the target enzymes using the Autodock package.Communicated by Ramaswamy H. Sarma.

Crystal structure, Hirshfeld surface analysis and density functional theory study of 1-nonyl-3-phenyl-quinoxalin-2-one

In the title mol-ecule, C23H28N2O, the phenyl ring is inclined to the quinoxaline ring system at a dihedral angle of 20.40 (9)°. In the crystal, C-H⋯O inter-actions between neighbouring mol-ecules form chains along the a-axis direction. Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H⋯H (70.6%), H⋯C/C⋯H (15.5%) and H⋯O/O⋯H (4.6%) inter-actions. The optimized structure calculated using density functional theory at the B3LYP/6-311 G(d,p) level is compared with the experimentally determined structure in the solid state. The calculated highest occupied mol-ecular orbital (HOMO) and lowest unoccupied mol-ecular orbital (LUMO) energy gap is 3.8904 eV. Part of the n-nonyl chain attached to one of the nitro-gen atoms of the quinoxaline ring system shows disorder and was refined with a double conformation with occupancies of 0.604 (11) and 0.396 (11).

Crystal structure, Hirshfeld surface analysis and inter-action energy calculation of 4-(furan-2-yl)-2-(6-methyl-2,4-dioxo-pyran-3-yl-idene)-2,3,4,5-tetra-hydro-1H-1,5-benzodiazepine

The title compound {systematic name: (S,E)-3-[4-(furan-2-yl)-2,3,4,5-tetra-hydro-1H-benzo[b][1,4]diazepin-2-yl-idene]-6-methyl-2H-pyran-2,4(3H)-dione}, C19H16N2O4, is constructed from a benzodiazepine ring system linked to furan and pendant di-hydro-pyran rings, where the benzene and furan rings are oriented at a dihedral angle of 48.7 (2)°. The pyran ring is modestly non-planar [largest deviation of 0.029 (4) Å from the least-squares plane] while the tetra-hydro-diazepine ring adopts a boat conformation. The rotational orientation of the pendant di-hydro-pyran ring is partially determined by an intra-molecular N-HDiazp⋯ODhydp (Diazp = diazepine and Dhydp = di-hydro-pyran) hydrogen bond. In the crystal, layers of mol-ecules parallel to the bc plane are formed by N-HDiazp⋯ODhydp hydrogen bonds and slipped π-π stacking inter-actions. The layers are connected by additional slipped π-π stacking inter-actions. A Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (46.8%), H⋯O/O⋯H (23.5%) and H⋯C/C⋯H (15.8%) inter-actions, indicating that van der Waals inter-actions are the dominant forces in the crystal packing. Computational chemistry indicates that in the crystal the N-H⋯O hydrogen-bond energy is 57.5 kJ mol-1.

Crystal structure and Hirshfeld surface analysis of 3-(4-meth-oxy-phen-yl)-1-methyl-4-phenyl-1H-pyrazolo-[3,4-d]pyrimidine

In the title mol-ecule, C19H16N4O, the planar pyrazolo-pyrimidine moiety is inclined to the attached phenyl rings by 35.42 (4) and 54.51 (6)°. In the crystal, adjacent mol-ecules are linked into chains parallel to [110] and [10] by C-H⋯O and C-H⋯N hydrogen bonds. Additional C-H⋯π(ring) inter-actions lead to the formation of the final three-dimensional network structure. The Hirshfeld surface analysis of the title compound suggests that the most significant contributions to the crystal packing are from H⋯H (48.2%), C⋯H/H⋯C (23.9%) and N⋯H/H⋯N (17.4%) contacts.

Crystal structure and Hirshfeld surface analysis of 5-[(5-nitro-1H-indazol-1-yl)meth-yl]-3-phenyl-4,5-di-hydro-isoxazole

In the title compound, C17H14N4O3, the indazole unit is planar to within 0.0171 (10) Å and makes dihedral angles of 6.50 (6) and 6.79 (4)°, respectively, with the nitro and pendant phenyl groups. The conformation of the oxazole ring is best described as an envelope. In the crystal, oblique stacks along the a-axis direction are formed by π-π stacking inter-actions between the indazole unit and the pendant phenyl rings of adjacent mol-ecules. The stacks are linked into pairs through C-H⋯O hydrogen bonds. Hirshfeld surface analysis and two-dimensional fingerprint plots indicate that the most important contributions to the crystal packing are from H⋯H (36.3%), O⋯H/H⋯O (23.4%), C⋯H/H⋯C (13.4%) and N⋯H/H⋯N (11.4%) inter-actions.

Crystal structure and Hirshfeld surface analysis of 5-methyl-1,2,4-triazolo[1,5-a]pyrimidine

The nine-membered ring system of the title compound, C6H6N4, is essentially planar. In the crystal, mol-ecules are linked via C-HTrz⋯NTrz and C-HPyrm⋯NTrz (Trz = triazole and Pyrm = pyrimidine) hydrogen bonds together with weaker C-HPyrm⋯NPyrm hydrogen bonds to form layers parallel to (02). The layers are further connected by π-π-stacking inter-actions between the nine-membered ring system [centroid-centroid = 3.7910 (8) Å], forming oblique stacks along the a-axis direction. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯N/N⋯H (40.1%), H⋯H (35.3%), H⋯C/C⋯H (9.5%), N⋯C/C⋯N (9.0%), N⋯N (3.1%) and C⋯C (3.0%) inter-actions and that hydrogen-bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. No significant C-H⋯π inter-actions are observed.

1-(3-Hydroxypropyl)-3-phenylquinoxalin-2(1H)-one

In the title molecule, C17H16N2O2, the quinoxaline portion is slightly folded about the N...N axis with an angle of 4.27 (4)°. In the crystal, O—H...O and weak C—H...O hydrogen bonds link molecules along the b-axis direction. In addition, two sets of weak C—H...π(ring) interactions form a two-dimensional `step' motif parallel to the bc plane.

2-Amino-5-methyl-1,2,4-triazolo[1,5-a]pyrimidin-7(4H)-one

The asymmetric unit of the title compound, C6H7N5O, consists of two molecules with almost identical conformations. In the crystal, inversion dimers linked by pairs of N—H...N hydrogen bonds occur for both molecules; further N—H...N and N—H...O hydrogen bonds connect the dimers into a three-dimensional network.

Ethyl 2-(5-methyl-1,2,4-triazolo[1,5-a]pyrimidin-7-yl)pent-4-enoate

In the title molecule, C13H16N4O2, the fused triazolopyrimidine ring system is planar. In the crystal, inversion-related C—H...O hydrogen bonds form dimers that are linked into chains extending along the a-axis direction by inversion-related C—H...π(ring) interactions.

1-Methyl-4-phenyl-3-[4-(trifluoromethyl)phenyl]-1H-pyrazolo[3,4-d]pyrimidine

In the title molecule, C19H13F3N4, the pyrazolopyrimidine unit is slightly non-planar [dihedral angle between the five- and six-membered rings = 3.03 (15)°]. In the crystal, offset head-to-tail π-stacking interactions between pyrazolopyrimidine units [centroid–centroid separation = 3.665 (2) Å] together with weak C—H...N hydrogen bonds form stepped chains propagating along the c-axis direction. The structure was refined as a two-component twin.

1-Methyl-1H-pyrazolo[3,4-d]pyrimidin-4(5H)-one

The title molecule, C6H6N4O, is essentially planar [dihedral angle between the rings = 0.46 (9)°]. The crystal structure consists of sheets of molecules lying parallel to (-111) formed by a combination of N—H...O, C—H...O and C—H...H hydrogen bonds. The sheets are connected through π–π stacking interactions.

N,N-Dimethyl-1H-pyrazolo[3,4-d]pyrimidin-4-amine monohydrate

The asymmetric unit of the title compound, C7H9N5·H2O, consists of two formula units differing slightly in the orientation of the dimethylamino groups. In the crystal, a combination of O—H...N and N—H...O hydrogen bonds involving the water molecules of crystallization, as well as slipped π-stacking interactions between pyrazolopyrimidine units form layers parallel to thebcplane.

Ethyl 2-allyl-2-(5-methyl-1,2,4-triazolo[1,5-a]pyrimidin-7-yl)pent-4-enoate

In the title molecule, C16H20N4O2, the dihedral angle between the planes of the fused rings is 2.26 (8)°. In the crystal, [\overline{2}10] chains of molecules linked by C—H...O and C—H...N hydrogen bonds arise, which are further linked by weak C—H...π interactions.

5-Nitro-1-(prop-2-en-1-yl)-1H-indazole

In the crystal, the title molecule, C10H9N3O2, packs in layers approximately parallel to (100), which are formed by the association of zigzag chains constructed by weak C—H...O interactions. The allyl group is disordered over two positions, with a ratio of their occupancies close to 70:30.

3-Acetyl-2-methyl-4H-pyrido[1,2-a]pyrimidin-4-one

In the title compound, C11H10N2O2, the pyridopyrimidine moiety deviates slightly from planarity. In the crystal, molecules stack along the a-axis direction assisted by π–π stacking interactions and C—H...O hydrogen bonds. The stacks are associated in centrosymmetric pairs through C—H...N hydrogen bonds.

(2Z)-2-Benzylidene-4-octadecyl-3,4-dihydro-2H-1,4-benzothiazin-3-one

The octadecyl chain in the title compound, C33H47NOS, is in the `fully extended' conformation. A puckering analysis of the thiazine ring was performed. The molecules form micellar blocks in the crystal by intercalation of the extended octadecyl chains and association of the dihydro benzothiazine units through C—H...O hydrogen bonds. These blocks are associated through intercalation of the pendant phenyl groups which reside on the outer edges of each block.

(3S)-3,8-Dibromo-4-phenyl-2,3-dihydro-1H-1,5-benzodiazapin-2-one

In the title compound, C15H10Br2N2O, one Br atom is disordered over two non-chemically equivalent sites, and as a consequence, the crystallized sample contains a mixture of isomers, viz. 98.4% of 3,8-dibromo-4-phenyl-2,3-dihydro-1H-1,5-benzodiazapin-2-one and 1.6% of 3,6-dibromo-4-phenyl-2,3-dihydro-1H-1,5-benzodiazapin-2-one. The seven-membered ring adopts a boat conformation. In the crystal, pairwise N—H...O hydrogen bonds form centrosymmetric dimers, which are associated in the crystal through a combination of π–π stacking and C—H...π(ring) interactions.

3,5-Diamino-4H-1,2,4-triazol-1-ium 4-nitrobenzoate dihydrate

The crystal of the title salt hydrate, C2H6N5+·C7H4NO4−·2H2O, is built up from a 3,5-diamino-4H-1,2,4-triazol-1-ium cation linked to a 4-nitrobenzoate anion and to two water molecules through strong hydrogen bonds. The triazolyl ring is virtually planar, with the maximum deviation from the mean plane being 0.003 (1) Å. Small twists are noted in the anion with the dihedral angles between the ring and carboxylate and nitro groups being 7.82 (13) and 9.10 (15)°, respectively. In the crystal, molecules are linked by N—H...O, N—H...N, O—H...O and C—H...O interactions, forming layers parallel to (-101). The sheets are linked by O—H...O hydrogen bonds and π–π interactions between triazole and benzene rings [inter-centroid separation = 3.4967 (8) Å] to form a three-dimensional structure.

Ethyl (2E)-3-dimethylamino-2-(5-methyl-1,2,4-triazolo[1,5-a]pyrimidin-7-yl)prop-2-enoate

In the title molecule, C13H17N5O2, the triazolopyrimidine ring system and the (dimethyamino)acrylate unit are nearly perpendicular to each other, subtending a dihedral angle of 78.55 (6)°. In the crystal, molecules are linked into aC(6) chain along theb-axis directionviaC—H...O hydrogen bonds.

1-Benzyl-4-phenyl-1H-1,5-benzodiazepin-2(3H)-one

In the title molecule, C22H18N2O, the seven-membered ring adopts a boat conformation with the planes of the pendant phenyl rings nearly perpendicular to the plane of the aromatic portion of the benzodiazepine core. Pairwise C—H...π(ring) interactions form inversion dimers which pack in zigzag layers associated through weak C—H...O hydrogen bonds.

2-Methyl-3-(3-methylisoxazol-5-yl)-4-oxo-4H-pyrido[1,2-a]pyrimidin-1-ium chloride

In the title molecular salt, C13H12N3O2+·Cl−, the oxazolyl ring is disordered over two orientations in a 0.536 (15):0.464 (15) ratio, both of which approximate to envelopes with the N atom as the flap in each case. The cation and anion are linked by a charge-assisted N—H...Cl hydrogen bond. In the extended structure, C—H...N, C—H...O and C—H...Cl interactions link the components into a three-dimensional network.

2-(2-Amino-5-methyl-1,2,4-triazolo[1,5-a]pyrimidin-7-yl)acetohydrazide monohydrate

In the crystal structure of the title molecule, C8H11N7O·H2O, a network of O—H...O, O—H...N, N—H...O and N—H...N hydrogen bonds links the components, forming layers which include the lattice water molecules. The layers are held together by π–π stacking interactions.

Crystal structure of (Z)-7,8-di-chloro-4-(2-oxo-propyl-idene)-4,5-di-hydro-1H-1,5-benzodiazepin-2(3H)-one

In the title compound, C12H10Cl2N2O2, the seven-membered heterocycle displays a half-chair conformation. The mean plane through the oxo-propyl-idene group makes a dihedral angle of 36.44 (9)° with the fused benzene ring. An intra-molecular N-H⋯O hydrogen bond to close an S(6) loop is noted. An important feature of the mol-ecular packing are N-H⋯O hydrogen bonds that lead to the formation of helical supra-molecular chains along the b axis.

A genome-wide scan for coronary heart disease suggests in Indo-Mauritians a susceptibility locus on chromosome 16p13 and replicates linkage with the metabolic syndrome on 3q27

Prevalence of coronary heart disease (CHD), of type 2 diabetes (T2DM) and of the metabolic syndrome are in Mauritius amongst the highest in the world. As T2DM and CHD are closely associated and have both a polygenic basis, we conducted a 10 cM genome scan with 403 microsatellite markers in 99 independent families of North-Eastern Indian origin including 535 individuals. Families were ascertained through a proband with CHD before 52 years of age and additional sibs with myocardial infarction (MI) or T2DM. Model-free two-point and multipoint linkage analysis were performed using the Mapmarker-Sibs (MLS) and maximum-likelihood-binomial (MLB) programs for autosomal markers and the Aspex program for chromosome X markers. In a second step, additional markers were studied to increase the genetic map density in three regions on chromosomes 3, 8 and 16 where initial indication for linkage was found. Our data show suggestive linkage with CHD on chromosome 16p13-pter with the MLS statistics at 8.69 cM (LOD = 3.06, P = 0.00017) which partially overlaps with a high pressure (HBP) peak. At the same locus, a nominal indication for linkage with T2DM was found in 35 large T2DM Pondicherian families also having Indian origin. With respect to region 8q23, we found suggestive linkage with T2DM (LOD = 2.55, P = 0.00058) as well as with HBP. On 3q27, we replicated previous indication for linkage found in Caucasians (for the metabolic syndrome and for diabetes) according to the categorized trait for CHD and MI with the MLB statistics (LOD = 2.13, P = 0.0009). The genome scan also revealed nominal evidence of linkage with CHD on 10q23 (LOD = 2.06, P = 0.00188). Interestingly, we detected in the same region overlapping linkages with three QTLs: age of onset of CHD (LOD = 2.03), HDL cholesterol (LOD = 1.48) and LDL/HDL ratio (LOD = 1.34). Ordered-subset analysis based on family body mass index ranking replicated finding on 2q37 for T2DM (at Calpain 10 locus). These results show the first evidence for susceptibility loci that predispose to CHD, T2DM and HBP in the context of the metabolic syndrome.