A Combined Experimental and Computational Study of Novel Benzotriazinone Carboxamides as Alpha-Glucosidase Inhibitors.

Diabetes is a chronic metabolic disorder of the endocrine system characterized by persistent hyperglycemia appears due to the deficiency or ineffective use of insulin. The glucose level of diabetic patients increases after every meal and medically recommended drugs are used to control hyperglycemia. Alpha-glucosidase inhibitors are used as antidiabetic medicine to delay the hydrolysis of complex carbohydrates. Acarbose, miglitol, and voglibose are commercial drugs but patients suffer side effects of flatulence, bloating, diarrhea, and loss of hunger. To explore a new antidiabetic drug, a series of benzotriazinone carboxamides was synthesized and their alpha-glucosidase inhibition potentials were measured using in vitro experiments. The compounds 14k and 14l were found to be strong inhibitors compared to the standard drug acarbose with IC50 values of 27.13 ± 0.12 and 32.14 ± 0.11 µM, respectively. In silico study of 14k and 14l was carried out using molecular docking to identify the type of interactions developed between these compounds and enzyme sites. Both potent compounds 14k and 14l exhibited effective docking scores by making their interactions with selected amino acid residues. Chemical hardness and orbital energy gap values were investigated using DFT studies and results depicted affinity of 14k and 14l towards biological molecules. All computational findings were found to be in good agreement with in vitro results.

Experimental and Computational Analysis of Newly Synthesized Benzotriazinone Sulfonamides as Alpha-Glucosidase Inhibitors.

Diabetes mellitus is a chronic metabolic disorder in which the pancreas secretes insulin but the body cells do not recognize it. As a result, carbohydrate metabolism causes hyperglycemia, which may be fatal for various organs. This disease is increasing day by day and it is prevalent among people of all ages, including young adults and children. Acarbose and miglitol are famous alpha-glucosidase inhibitors but they complicate patients with the problems of flatulence, pain, bloating, diarrhea, and loss of appetite. To overcome these challenges, it is crucial to discover new anti-diabetic drugs with minimal side effects. For this purpose, benzotriazinone sulfonamides were synthesized and their structures were characterized by FT-IR, 1H-NMR and 13C-NMR spectroscopy. In vitro alpha-glucosidase inhibition studies of all synthesized hybrids were conducted using the spectrophotometric method. The synthesized compounds revealed moderate-to-good inhibition activity; in particular, nitro derivatives 12e and 12f were found to be the most effective inhibitors against this enzyme, with IC50 values of 32.37 ± 0.15 µM and 37.75 ± 0.11 µM. In silico studies, including molecular docking as well as DFT analysis, also strengthened the experimental findings. Both leading compounds 12e and 12f showed strong hydrogen bonding interactions within the enzyme cavity. DFT studies also reinforced the strong binding interactions of these derivatives with biological molecules due to their lowest chemical hardness values and lowest orbital energy gap values.

Synthesis, antioxidant, in silico and computational investigation of 2,5-dihydroxyacetophenone derived chloro-substituted hydroxychalcones, hydroxyflavanones and hydroxyflavindogenides.

An imbalance between reactive oxygen species (ROS) and their elimination by antioxidants damages the cell and infect whole organism. The biological defence system against oxidative stress injury is Kelch-like ECH associated protein 1 (Keap1)-nuclear factor erythroid 2-related factor 2 (Nrf2)-antioxidant response elements (ARE) pathways. Antioxidants activate the Nrf2-ARE-Keap1 pathway and suppress the oxidative stress. Flavonoids are well known medicinal compounds inheriting antioxidant efficacy and wide spectrum of pharmacological activities. The study is aimed to synthesise, characterize and evaluate pharmacological activities of synthesized chloro-derivatives of flavonoids. Chloro-derivatives of flavonoids were synthesized and characterized by IR, 1H NMR and 13C NMR. Antioxidant potential of each synthesized compound was evaluated and then subjected to molecular docking with Keap1 (PDB ID: 2FLU) for the activation of Nrf2 and computational studies were performed by using DFT approach. Among the synthesized compounds compound 1a exhibited lower IC50 value. While docking and computational studies infer that compound 3c is a good Nrf2 activator and radical scavenger with highest docking score and lower energy gaps and IP values compared to references. Hence, it might be considered for further molecular studies for the treatment of inflammatory diseases through Nrf2-ARE-Keap1 pathway. Communicated by Ramaswamy H. Sarma.HighlightsChloro-substituted hydroxychalcones, hydroxyflavanones and hydroxyflavindogenides were synthesized.Antioxidant potential was accessed, compound 1a exhibited good antioxidant potential.In silico study was performed with Keap1, compound 3c have shown highest docking score with Keap1.DFT approach was used to explore the structure activity relationship.

Synthesis and optical studies of Y-shaped imidazole derivatives.

A novel series Y-shaped π-expanded imidazole based chromophores was designed and synthesized. The series contains thirteen 2-aryl-4,5-bis[2-(aryl)vinyl)]-1H-imidazoles (6a-6m), which were characterized by spectroscopic analysis. The structures of compounds 6d and 6j were also confirmed by X-ray crystallographic analysis. The optical studies were investigated using absorption and emission measurements in dichloromethane. The fluorescence quantum yields were observed varying in 0.22-0.59 range, but the compounds with nitro substituent did not show the fluorescence. The absorption and emission study of the series helped us to understand the effect of substituents on the optical properties of compounds as well.

Imidazole-pyrazole hybrids: Synthesis, characterization and in-vitro bioevaluation against α-glucosidase enzyme with molecular docking studies.

Herein, substituted imidazole-pyrazole hybrids (2a-2n) were prepared via a multi component reaction employing pyrazole-4-carbaldehydes (1a-1d), ammonium acetate, benzil and arylamines as reactants. All the new compounds were characterized through their spectral and elemental analyses. Further these compounds were tested against α-glucosidase enzyme. The compounds 2k, 2l and 2n possessed good inhibition potencies, however, compounds 2f (IC50 value: 25.19 ±â€¯0.004 µM) and 2m (IC50 value: 33.62 ±â€¯0.03 µM) were the most effective compounds of the series. Furthermore, molecular docking helped to understand the binding interactions of 2f and 2m with the understudy yeast's α-glucosidase enzyme.

Molecular Docking, Computational, and Antithrombotic Studies of Novel 1,3,4-Oxadiazole Derivatives.

A new series of 1,3,4-oxadiazoles derivatives was synthesized, characterized, and evaluated for their in vitro and in vivo anti-thrombotic activity. Compounds (3a⁻3i) exhibited significant clot lysis with respect to reference drug streptokinase (30,000 IU), and enhanced clotting time (CT) values (130⁻342 s) than heparin (110 s). High affinity towards 1NFY with greater docking score was observed for the compounds (3a, 3i, 3e, 3d, and 3h) than the control ligand RPR200095. In addition, impressive inhibitory potential against factor Xa (F-Xa) was observed with higher docking scores (5612⁻6270) with Atomic Contact Energy (ACE) values (-189.68 to -352.28 kcal/mol) than the control ligand RPR200095 (Docking score 5192; ACE -197.81 kcal/mol). In vitro, in vivo, and in silico results proposed that these newly synthesized compounds might be used as anticoagulant agents.

Biological evaluation of new imidazole derivatives tethered with indole moiety as potent α-glucosidase inhibitors.

A series of triarylimidazoles substituted with 2-arylindoles (4a-4j) were prepared and evaluated for their in vitro α-Glucosidase inhibition. α-Glucosidase inhibition assay displayed a new class of highly potent agents The new compounds showed significant α-glucosidase inhibitory activity as compared to the standard inhibitor acrabose. Structures of synthesized compounds were determined by using Mass spectrometry FT-IR, 1H NMR and 13C NMR.

Hetarylcoumarins: Synthesis and biological evaluation as potent α-glucosidase inhibitors.

In search of better α-glucosidase inhibitors, a series of novel hetarylcoumarins (3a-3j) were designed and synthesized through a facile multicomponent route where p-toluenesulfonic acid (PTSA) was explored as an efficient catalyst. These new scaffolds were further evaluated for their α-glucosidase inhibition potentials. All the derivatives exhibited good to excellent results which were comparable or even better than of standard drug acarbose. Of these compounds, a dihalogenated compound 3f was found to be the most effective one with IC50: 2.53±0.002µM. Molecular docking has predicted the plausible binding interactions of compounds 3f, 3g and 3j with α-glucosidase.

Green synthesis, inhibition studies of yeast α-glucosidase and molecular docking of pyrazolylpyridazine amines.

An efficient and environmentally benign simple fusion reaction of 3-chloro-6-(3,5-dimethyl-1H-pyrazol-1-yl)pyridazine (1a) or 3-chloro-6-(3,5-dimethyl-4-nitro-1H-pyrazol-1-yl)pyridazine (2a) with different aliphatic/aromatic amines have produced a series of novel pyrazolylpyridazine amines (4a-4c &5a-5m). All compounds exhibited moderate in vitro yeast α-glucosidase inhibition except m-chloro derivative 5g, which was found potent inhibitor of this enzyme with IC50 value of 19.27±0.005µM. The molecular docking further helped in understanding the structure activity relationship of these compounds including 5g.

In search of new α-glucosidase inhibitors: Imidazolylpyrazole derivatives.

Under three different reaction conditions (conventional heating, microwave irradiations and amino acid catalysis), a series of imidazolylpyrazoles (2a-2k) were synthesized in good to excellent yields from a mixture of three precursors: aryl(hetaryl)pyrazole-4-carbaldehydes (1a-1k), benzil and ammonium acetate. α-Glucosidase inhibition assay revealed a new class of highly potent agents wherein each compound displayed significant inhibitory potentials (in terms of percentage inhibition and relative IC50 values) as compared to that of the reference drug (Acarbose). Moreover, molecular modelling of most potent compounds 2h, 2j and 2k also helped in understanding the structure and activity relationship.

Crystal structure of 3,4-di-chloro-anilinium hydrogen phthalate.

In the title salt, C6H6Cl2N(+)·C8H5O4 (-), the carb-oxy-lic acid and carboxyl-ate groups of the anion form dihedral angles of 20.79 (19) and 74.76 (14)°, respectively, with the plane of the benzene ring. In the crystal, mol-ecules are assembled into a two-dimensional polymeric network parallel to (100) via N-H⋯O and O-H⋯O hydrogen bonds. In addition, within the layer, there are π-π stacking inter-actions between the benzene rings of the cation and the anion [centroid-centroid distance = 3.6794 (17) Å]. A weak C-H⋯O interaction is also observed.

Discovery of indole-based tetraarylimidazoles as potent inhibitors of urease with low antilipoxygenase activity.

A series of tetraarylimidazoles (5A-5O) were prepared by one pot four component condensation reactions of 2-arylindole-3-carbaldehydes, substituted anilines, benzil and ammonium acetate in acetic acid. The synthesized compounds exhibited potent antiurease activity with IC50 values ranging from 0.12 ± 0.06 µM to 29.12 ± 0.18 µM as compared with thiourea. However, low inhibition profiles were observed for lipoxygenase. The data show that tetraarylimidazoles containing a substituted 2-penylindole have emerged as a new class of potent inhibitors of urease enzyme.

Crystal structure of (4Z)-4-[(2E)-1-hydroxy-3-(naphthalen-2-yl)prop-2-en-1-yl-idene]-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one.

In the title compound, C23H18N2O2, the pyrazole ring subtends dihedral angles of 2.01 (13) and 1.55 (10)° with the pendant benzene ring and the naphthalene ring system, respectively. The mol-ecule is almost planar (r.m.s. deviation for the 27 non-H atoms = 0.025 Å) and intra-molecular O-H⋯O and C-H⋯O hydrogen bonds both close S(6) loops. In the crystal, very weak aromatic π-π stacking inter-actions between the benzene and the pyrazole rings, with centroid-centroid distances of 3.8913 (14) and 3.9285 (15) Å, are observed.

Crystal structure of (4Z)-4-[(2E)-3-(4-chloro-phen-yl)-1-hy-droxy-prop-2-en-1-yl-idene]-5-methyl-2-phenyl-1H-pyrazol-5(4H)-one.

In the the asymmetric unit of the title compound, C19H15ClN2O2, there are two symmetry-independent mol-ecules, which adopt similar conformations. The largest difference is observed in the dihedral angles between the phenyl and the pyrazole fragments [17.00 (12) and 23.42 (10)°]. A strong intra-molecular O-H⋯O hydrogen bond with the S (6) motif is observed in both mol-ecules. Pairs of π-π stacking inter-actions between the phenyl groups [centroid-centroid distances = 3.6627 (13) and 3.7156 (14) Å] assemble the mol-ecules into two types of centrosymmetric dimers. Weak C-H⋯O inter-actions connect mol-ecules into chains along the b axis.

Crystal structure of (4Z)-4-[(2E)-3-(2-chloro-phen-yl)-1-hy-droxy-prop-2-en-1-yl-idene]-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one.

In the title compound, C19H15ClN2O2, the pyrazole ring is almost planar (r.m.s. deviation = 0.002 Å) and subtends dihedral angles of 5.31 (16) and 1.86 (16)° with the phenyl and chloro-benzene rings, respectively. An intra-molecular O-H⋯O hydrogen bond closes an S(6) ring and a short C-H⋯O contact is also observed. In the crystal, mol-ecules are linked by weak C-H⋯O inter-actions to generate (001) sheets. Weak aromatic π-π inter-actions between the chloro-benzene and pyrazole rings, with a centroid-centroid distance of 3.7956 (17) Šare also observed.

Crystal structure of 3-(3,4-di-methyl-anilino)-2-benzo-furan-1(3H)-one.

In the title compound, C16H15NO2, the 2-benzo-furan-1(3H)-one and 3,4-di-methyl-aniline fragments are oriented with a dihedral angle of 89.12 (5)°. N-H⋯O hydrogen-bond inter-actions join mol-ecules into C(6) chains propagating along the a axis. In addition, there are π-π stacking inter-actions between the 2-benzo-furan-one benzene rings [centroid-centroid dis-tance = 3.7870 (13) Å] and C-H⋯π inter-actions between one of the methyl groups and the 3,4-di-methyl-aniline benzene ring.

Crystal structure of (4E)-4-(8-meth-oxy-2H-chromen-2-yl-idene)-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one.

In the title compound, C20H16N2O3, the phenyl substituent attached to the pyrazole ring makes a dihedral angle of 4.87 (7)° with the rest of the mol-ecule. In the crystal, mol-ecules are connected into inversion dimers of the R 2 (2)(14) type by pairs of C-H⋯O inter-actions. π-π inter-actions exist between the benzene and pyrazole rings at a distance of 3.701 (1) Å. Similarly, π-π inter-actions are present at a centroid-centroid distance of 3.601 (1) Šbetween the oxygen-containing heterocyclic ring and meth-oxy substituted aromatic ring of a neighbouring mol-ecule. Additional C-H⋯π and C=O⋯π inter-actions are also observed.

Crystal structure of 4-chloro-2-{(E)-[(3,4-di-methyl-phen-yl)imino]-meth-yl}phenol.

In the title compound, C15H14ClNO, which is isostructural with its bromo analogue [Tahir et al. (2012 ▶). Acta Cryst., E68, o2730], the dihedral angle between the planes of the aromatic rings is 2.71 (7)° and an intra-molecular O-H⋯N hydrogen bond closes an S(6) ring. In the crystal, extremely weak C-H⋯π inter-actions link the mol-ecules into a three-dimensional network.

1-{[(E)-(4-{[(2Z)-2,3-Di-hydro-1,3-thia-zol-2-yl-idene]sulfamo-yl}phen-yl)iminium-yl]meth-yl}naphthalen-2-olate.

In the title zwitterionic compound, C20H15N3O3S2, the 2-hy-droxy-naphthalene-1-carbaldehyde group A, the anilinic unit B and the 1,3-thia-zol-2(3H)-imine group C are each approximately planar with r.m.s. deviation of 0.0721, 0.0412 and 0.0125 Å, respectively. The dihedral angles between A/B, A/C and B/C are 24.70 (10), 79.97 (7) and 83.14 (6)°, respectively. There is an intra-molecular S(6) motif involving the imine N-H and the naphtho-late O atom. In the crystal, inversion-related mol-ecules form dimers as a result of N-H⋯N and N-H⋯O hydrogen bonds with R 2 (2)(8) and R 1 (2)(4) motifs, respectively. Weak π-π inter-actions between the benzene and naphthyl rings of inversion-related mol-ecules have ring centroid-centroid distances of 3.638 (2) and 4.041 (2) Å. A C-H⋯π inter-action occurs between the thia-zol ring and the benzene ring of an adjacent mol-ecule.

Potential antibacterial activity of coumarin and coumarin-3-acetic acid derivatives.

Coumarin and coumarin-3-acetic acid derivatives were synthesized by reacting phenols with malic acid, ethyl acetoacetate and ethyl acetylsuccinate in appropriate reaction conditions. All synthesized compounds were subjected to test for their antimicrobial activities against variety of gram positive (Bacillus subtilis, Staphylococcus aureus) and gram negative bacterial stains (Shigella sonnei, Escherichia coli) by agar dilution method. Several of them exhibited appreciable good antibacterial activity against the different strains of gram positive and gram negative bacteria. These findings suggest a great potential of these compounds for screening and use as antibacterial agents for further studies with a battery of bacteria.