Syed Umar Farooq Rizvi

Anti-HIV-1 and cytotoxicity studies of piperidyl-thienyl chalcones and their 2-pyrazoline derivatives

A series of 12 new pyrazoline derivatives was prepared from piperidyl chalcones, which in turn were synthesized by condensing 4-piperidin-1-ylbenzaldehyde with diverse acetylthiophenes. The target compounds were characterized by spectroscopic techniques (NMR, IR, MS) and elemental analysis. All the compounds were screened for cytotoxic and anti-HIV-1 activities. Compounds 1c, 1g, 1j, 2a, 2c, 2e, 2g, and 2k demonstrated potential anti-HIV activity but were cytotoxic except for 2e and 2k, which displayed no cytotoxicity in primary human cells. Bioassay results show that the type and positions of the substituents seem to be critical for their cytotoxic and anti-HIV-1 activities.

Discovery and molecular docking of quinolyl-thienyl chalcones as anti-angiogenic agents targeting VEGFR-2 tyrosine kinase.

Vascular endothelial growth factor Receptor-2 (VEGFR-2) kinase inhibition is one of the well established strategies to promptly tackle tumor growth by suppression of angiogenesis. In the current study, structure-based virtual screening methodology of a series of quinolyl-thienyl chalcones indicated their strong potential as VEGFR-2 kinase inhibitors. In vitro VEGFR-2 kinase inhibitory activity was found to be significant (compound 19, IC(50): 73.41nM). All compounds showed significant inhibition of human umbilical vein endothelial cells (HUVEC) proliferation (compound 19, IC(50): 21.78nM). Molecular interactions of the compounds were studied using molecular docking studies.

Novel quinolyl-thienyl chalcones and their 2-pyrazoline derivatives with diverse substitution pattern as antileishmanial agents against Leishmania major

A series of twenty-two new pyrazoline derivatives was prepared from quinoline-based chalcones which in turn were synthesized by condensing formylquinolines with diverse acetylthiophenes. The titled compounds were characterized by spectroscopic techniques (NMR, IR and MS) and elemental analysis. All the compounds were screened for antileishmanial activities. Compounds 1e, 1f, 2a, 2c, 2d, 2g, 2k, and 4a were found potentially active antileishmanial agents. Bioassay results show that the type and positions of the substituents seem to be critical for their antileishmanial activities.

Molecular docking and antiviral activity of N-substituted benzyl/phenyl-2-(3,4-dimethyl-5,5-dioxidopyrazolo[4,3-c][1,2]benzothiazin-2(4H)-yl)acetamides.

Two series of fifteen N-substituted benzyl/phenyl-2-(3,4-dimethyl-5,5-dioxidopyrazolo[4,3-c][1,2]benzothiazin-2(4H)-yl)acetamides were screened for anti-HIV-1 activity and cytotoxicity. The compounds 6a, 6d, 6e, 6g and 6i from the series 6a-i of benzylamides and 7a, 7b, 7c, 7d and 7e from the series 7a-f of anilides were identified as effective anti-HIV-1 agents with EC50 values <20μM. Among these compounds that displayed anti-HIV-1 activity, 6a, 6e, 6g and 6i showed no toxicity in human PBM, CEM and Vero cells, with the exception of 6a which displayed toxicity in Vero cells. Molecular docking of these compounds provided insight into the molecular mechanism and it was found that 6e, 6g and 6i bound deeply in the NNRTI binding pocket of the HIV-1 reverse transcriptase, using RT-bound nevirapine X-ray data and molecular docking for validation, showing the potential of these new structures as inhibitors of this viral enzyme.

(E)-3-(2-Chloro-6-methyl-3-quinol-yl)-1-(2,3-dihydro-1,4-benzodioxin-6-yl)prop-2-en-1-one.

In the title molecule, C21H16ClNO3, the quinoline and benzene rings are inclined at 56.96 (6)° with respect to each other and the dioxine ring is in a twist-chair conformation. The structure is devoid of any classical hydrogen bonds. Rather weak intermolecular hydrogen-bonding interactions of the types C—H⋯N and C—H⋯O are present, consolidating the crystal structure.

Erratum to: Synthesis and biological studies of a novel series of 4-(4-(1H-imidazol-1-yl)phenyl)-6-arylpyrimidin-2-amines

A novel series of eleven 4-(4-(1H-imidazol-1-yl)phenyl)-6-arylpyrimidin-2-amines has been prepared from synthesized 3-[4-(1H-imidazol-1-yl) phenyl]prop-2-en-1-ones and evaluated for phosphodiesterase (PDE) inhibition and antimicrobial activities. N-arylation of imidazole with 4-fluorobenzaldehyde using hexadecyltrimethylammonium bromide as catalyst gave 4-(1H-imidazol-1-yl) benzaldehyde which on treatment with substituted acetophenones yielded corresponding chalcones (1a–1k). Each chalcone on further reaction with guanidine hydrochloride resulted in title compounds (2a–2k). Pyrimidines thus synthesized were subjected to biological studies. Some compounds showed marked activities in PDE inhibition and anti-bacterial and anti-fungal bioassays.

(2E)-3-(2-Chloro-6-methyl-3-quinol­yl)-1-(1-naphth­yl)prop-2-en-1-one

In the title molecule, C23H16ClNO, the quinoline and naphthalene ring systems are individually planar, with maximum deviations of 0.020 (2) and 0.033 (2) Å, respectively, and are inclined at a dihedral angle of 30.01 (4)°. Intramolecular C—H⋯O and C—H⋯Cl interactions occur. The crystal structure is devoid of any classical hydrogen bonds, but symmetry-related molecules are linked via weak C—H⋯Cl interactions, forming chains propagating in [001].

Quinoline containing chalcone derivatives as cholinesterase inhibitors and their in silico modeling studies

Cholinesterases (ChEs) play a vital role in regulating cholinergic transmission. Inhibition of ChEs is thought to be an emerging and useful therapeutic target for neurodegenerative disorders through restoration of acetylcholine (ACh) levels in the brain (e.g. Alzheimers disease). To increase the chemical diversity of cholinesterase inhibitors, a series of quinoline chalcones derivatives were tested against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) isoenzymes. All tested compounds (4a-1; 5a-s) exhibited inhibitory activities against AChE and BChE to a considerable extent. Molecular docking studies were performed by using homology models on both AChE and BChE isoenzymes with the aim of exploring probable binding modes of the most potent inhibitor. In order to evaluate drug likeness of newly tested molecules, we carried out in-silico ADME evaluation. All compounds displayed favourable ADME findings which predict good oral bioavailability of these derivatives. Due to an excellent ADME profile the tested compounds were predicted to be safer which can be considered as novel cholinesterase inhibitors.

N'-[(E)-4-(Diethyl-amino)benzyl-idene]-4-nitro-benzohydrazide monohydrate.

In the title compound, C18H20N4O3·H2O, the two aromatic rings are linked through a methylidenehydrazide fragment, which is fully extended with C—C—N—N, C—N—N=C and N—N=C—C torsion angles of 179.4 (2), 174.7 (2) and 178.3 (2)°, respectively. The dihedral angle between the two aromatic rings is 7.01 (8)°. In the crystal structure, the water of hydration is involved in extensive hydrogen bonding. Intermolecular O—H⋯O, N—H⋯O and O—H⋯N hydrogen bonds link the components of the structure into a two-dimensional network and additional stabilization is provided by weak intermolecular C—H⋯O hydrogen bonds.