Kanuprasad D. Patel

Pyrazole clubbed triazolo[1,5-a]pyrimidine hybrids as an anti-tubercular agents: Synthesis, in vitro screening and molecular docking study.

A series of novel pyrazole linked triazolo-pyrimidine hybrids were synthesized and evaluated for their anti-tuberculosis activity against M.tb H37Rv strain. Some of the screened entities rendered promising anti-tb activity (MIC: 0.39μg/mL) and were found non toxic against Vero cells (IC50: ⩾20μg/mL). Further, the docking study against wild type InhA enzyme of Mycobacterium tuberculosis using Glide reproduced the most active inhibitors (J21 and J27) with lowest binding energies and highest Glide XP scores demonstrating efficient binding to the active pocket. Additionally, the enzyme inhibition assay and ADME prediction of the active proved to be an attest to the possibility of developing compound J27 as a potent anti-tubercular lead.

Dicoumarol complexes of Cu(II) based on 1,10-phenanthroline: Synthesis, X-ray diffraction studies, thermal behavior and biological evaluation

A series of Cu(II) complexes containing dicoumarol derivatives and 1, 10-phenanthroline have been synthesized. Structural and spectroscopic properties of ligands were studied on the basis of mass spectra, NMR ((1)H and (13)C) spectra, FT-IR spectrophotometry and elemental analysis, while physico-chemical, spectroscopic and thermal properties of mixed ligand complexes have been studied on the basis of infrared spectra, mass spectra, electronic spectra, powder X-ray diffraction, elemental analysis and thermogravimetric analysis. X-ray diffraction study suggested the suitable octahedral geometry for hexa-coordinated state. The kinetic parameters such as order of reaction (n), energy of activation (Ea), entropy (S(*)), pre-exponential factor (A), enthalpy (H(*)) and Gibbs free energy (G(*)) have been calculated using Freeman-Carroll method. Ferric-reducing antioxidant power (FRAP) of all complexes were measured. All the compounds were screened for their antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Streptococcus pyogenes and Bacillus subtilis, while antifungal activity against Candida albicans and Aspergillus niger have been carried out. Also compounds against Mycobacterium tuberculosis shows clear enhancement in the anti-tubercular activity upon copper complexation.

Thermal, kinetic, spectroscopic studies and anti-microbial, anti-tuberculosis, anti-oxidant properties of clioquinol and benzo-coumarin derivatives mixed complexes with copper ion

A series of six Cu(II) complexes of clioquinol with benzo-coumarin derivatives have been synthesized. Physico-chemical, spectroscopic, and thermal properties of the complexes have been studied on the basis of infrared spectra, mass spectra, NMR spectra, electronic spectra, elemental analyses, and thermogravimetric analyses. The kinetic parameters such as order of reaction (n), energy of activation (Ea), entropy (S*), pre-exponential factor (A), enthalpy (H*), and Gibbs free energy (G*) have been calculated using Freeman-Carroll method. All the compounds were screened for their anti-bacterial activity against Escherichia coli, Pseudomonas aeruginosa, Streptococcus pyogenes, Bacillus subtilis, and anti-fungal activity against Candida albicans and Aspergillus niger. Ferric-reducing anti-oxidant power of all complexes were measured. Also the compounds against Mycobacterium tuberculosis shows clear enhancement in the anti-tubercular activity upon copper complexation.Graphical abstractStructural, spectroscopic, and biological aspects of ligands and its metal complexes have been studied on the basis of mass spectra, NMR, FT-IR spectrophotometry, and elemental analyses. Thermal behavior and kinetic properties of complexes were discussed. The structure of compounds has been monitored for their in vitro anti-microbial, anti-oxidant, and anti-tuberculosis activity.

Microwave Assisted Synthesis of Pyrimidines in Ionic Liquid and Their Potency as Non‐Classical Malarial Antifolates

Synthesis of pyrazole‐linked triazolo‐pyrimidine hybrids was achieved by employing Biginelli‐type reaction methodology in an ionic liquid (triethylammonium acetate) under microwave irradiation. This method proved to be highly efficient and the ionic liquid employed was found recyclable for up to five consecutive cycles. The synthesized molecules were further screened for their antimalarial efficacy screening out the active scaffolds J15, J18, J21, J24, J27, and J30. The active molecules were evaluated in an enzyme inhibition study against the active Plasmodium falciparum dihydrofolate reductase (Pf‐DHFR), computationally as well as in vitro, demonstrating their potency as DHFR inhibitors. The active entities were also investigated for their oral bioavailability by predicting ADME properties in silico, indicating good bioavailability.

Cu(II) and Ni(II) complexes of coumarin derivatives with fourth generation flouroquinolone: synthesis, characterization, microbicidal and antioxidant assay

New Cu(II) and Ni(II) complexes of acetyl coumarin derivatives with gatifloxacin were synthesized. Characterization of the complexes was carried out by elemental analysis, FT-IR, FAB-MS, electronic spectra and magnetic measurement along with thermo gravimetric studies. Thermal study reveals the absence of coordinated water molecule in case of Cu(II) complexes. All the Cu(II) complexes were found more potent antibacterial activity compared to Ni(II) complexes. The antituberculosis data have shown that copper conjugation may be advantageous in designing highly effective drugs for antitubercular therapy. These complexes were also found to be potent antioxidizing agents comprising radical scavenging capability and ferric reducing abilities.

Diarylpyrazole Ligated Dihydropyrimidine Hybrids as Potent Non-Classical Antifolates and Their Efficacy Against Plasmodium falciparum

A series of diarylpyrazole clubbed dihydropyrimidine derivatives (J1–J30) was synthesized under microwave‐assisted heating conditions by employing Biginelli reaction methodology and utilizing triethylammonium acetate both as a catalyst and as reaction medium, leading towards a greener reaction pathway. The synthesized entities were screened for their antimalarial efficacy against a Plasmodium falciparum strain in vitro. The active entities (J9, J15, J21, J25, and J27) obtained out of the in vitro screening were further evaluated for their enzyme inhibitory potency against the Pf‐DHFR enzyme in vitro as well as in silico using Glide. Furthermore, the active scaffolds were tested for their cytotoxicity against Vero cells, proving their nontoxic behavior and selectivity. The ADME parameters were also evaluated and predicted in silico, indicating good oral bioavailability of the compounds.

Synthesis, Thermal, and Biological Studies of Newly Synthesized Cu(II) Complexes With Ciprofloxacin Based on Bromo-Coumarins Derivatives

The authors describe synthesis, characterization, and biological evaluation of Cu(II) complexes. Characterization of ligands has been carried out by elemental analysis, melting point, mass spectra, (1H & 13C) NMR, and FT-IR, while structure of metal complexes was confirmed by electronic spectra and FAB-mass spectral studies. Spectral studies confirm ligands is mono functional bidentate and octahedral environment around metal ions. Thermal behavior of Cu(II) complexes were investigated by means of TGA and magnetic measurements. The kinetic parameters are reported using the Freeman-Carroll method. Complexes were found significant potent antimicrobial and antioxidant activities compared to parent ligands employed for complexation. Supplemental materials are available for this article. Go to the publishers online edition of Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry to view the supplemental file.