Anti-HIV activity of new pyrazolobenzothiazine 5,5-dioxide-based acetohydrazides

A series of fifteen new 2-[3-(3-chlorophenyl)-5,5-dioxidobenzo[e]pyrazolo[4,3-c][1,2]thiazin-4(2H)-yl]-N'-arylmethyleneacetohydrazides (5a-o) were synthesized and screened for their anti-HIV-1 and cytotoxicity activity. Out of fifteen pyrazolobenzothiazine-based hydrazones, thirteen were found to be active inhibitors of HIV with EC50 values <20 μM. Moreover, the cytotoxicity results showed that most of the compounds were toxic to PBM, CEM and Vero cell lines. This information could be used for structural modifications to acquire good candidates of HIV drugs.

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.

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.

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)-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 (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) Å between 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 (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) Å are also observed.

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.

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.

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.

Cholinesterase Inhibitory Activities of N-Phenylthiazol-2-Amine Derivatives and their Molecular Docking Studies

Alzheimer's disease (AD) is a type of neurodegenerative disorder which is responsible for many cognitive dysfunctions. According to the most accepted cholinergic hypothesis, cholinesterases have a major role in AD symptoms. The use of small molecules as inhibitors is one of the most useful strategies to control AD. In the present work, a series of N-phenylthiazol-2-amine derivatives was screened against acetylcholinesterase (AChE) from Electrophorus electricus and butyrylcholinesterase (BChE) from horse serum by using Ellman's method, using neostigmine and donepezil as reference drugs. Some of the assayed compounds proved to be potent inhibitors for AChE and BChE activity. N-(2,3-dimethylphenyl)thiazol-2-amine, 3j was found to be the most active inhibitor among the series with IC50 value of 0.009 ± 0.002 µM and 0.646 ± 0.012 µM against AChE and BChE, respectively. Molecular docking studies were carried out in order to better understand the ligand binding site interactions.

Synthesis of novel indenoquinoxaline derivatives as potent α-glucosidase inhibitors

A series of new N-(11H-Indeno[1,2-b]quinoxalin-11-ylidene)benzohydrazide derivatives (3a-3p) were synthesized and evaluated for their α-glucosidase inhibitory activity. The synthesized compounds 3d, 3f, 3g, 3k, 3n, 3p and 4 showed significant α-glucosidase inhibitory activity as compared to acrabose, a standard drug used to treat type II diabetes. Structures of the synthesized compounds were determined by using FT-IR, (1)H NMR, (13)C NMR, mass spectrometry and elemental analysis techniques.