Papers by Narendra Kr Chaudhary
Today, the entire globe is struggling to deal with the greatest pandemic of the century, COVID-19... more Today, the entire globe is struggling to deal with the greatest pandemic of the century, COVID-19. With no clinically approved treatments available, we are left with no options other than following the preventive measures issued by the World Health Organization (WHO). Among many others, hand washing with soap and water has been emphasized the most because it is cost-effective and easily accessible to the general public. Various studies have reported that soaps offer unique chemical properties that can disinfect the virus as a whole. However, there is still ambiguity in the general public about whether soaps can really shield us from this highly contagious disease. In an attempt to help eliminate the ambiguity, we analyzed the mechanisms underlying the efficacy of soap and its prospect for preventing the spread of COVID-19. In this paper, we have provided an overview of the history and characteristics of SARS-CoV-2 (COVID-19), the detailed mechanisms of the deactivation of viruses by...
Complexation behavior of novel ligand derived from biologically active tetracycline and oxime wit... more Complexation behavior of novel ligand derived from biologically active tetracycline and oxime with ZR (IV), TH (IV), CE (IV) and HF (IV) synthesis, spectroscopic characterization and molecular modeling Abstract The aim of this paper is to synthesis novel ligand derived from biologically active molecules, tetracycline and oxime and study of its complexation behavior with transition and inner transition metal ions. The crystallinity and cell dimensions were carried out by Crysfire software programme having different crystal systems as well as optimized structure was studied by MM2 programme.
International Research Journal of Pure and Applied Chemistry, 2015
A novel Schiff base ligand was synthesized from Kanamycin and methyl ester of Amoxicillin in stoi... more A novel Schiff base ligand was synthesized from Kanamycin and methyl ester of Amoxicillin in stoichiometric ratio. Three metal chlorides viz. CuCl 2 .2H 2 O, CoCl 2 .6H 2 O and ZnCl 2 were used for the synthesis of respective metal complexes from synthesized novel ligand. The proposed structure of the complexes have been established by various microanalytical and spectral techniques like elemental analysis, TG/DTA studies, conductivity measurement, IR, 1 H NMR, Electronic and mass spectrometry. Various shifting in the band positions in IR spectra of the complexes suggested coordination of metal ions through azomethine N and O-atoms of the novel ligand. Spectral studies concluded pentadentate nature of ligand. The correct stereochemistry of the complexes was optimized by MM2 calculations programmed in CsChem3D Ultra-11 software. The crystal
British Journal of Pharmaceutical Research
Aims: To isolate and investigate the antibacterial potency of novel compound obtained from methan... more Aims: To isolate and investigate the antibacterial potency of novel compound obtained from methanolic extract of Curcuma longa rhizome. Place and Duration of Study: Bio-inorganic and Materials Chemistry Research laboratory, MMAM Campus (Tribhuvan university), Biratnagar, Nepal. The experimental work was done between March 2014 and August 2014. Methodology: The crude methanolic extract was prepared by digesting powdered Curcuma longa rhizome in distilled methanol and chromatographic technique like TLC and column chromatography were applied to isolate the new compound. The structural determination with proposed molecular structure was ascertained by different spectral techniques like IR, 1 H NMR and TOF-MS studies and correct stereochemistry was assured by molecular modeling programmed software. The antibacterial potency of the compound was checked by Kirby Bauer paper disc diffusion method, using Mueller-Hinton's nutrient agar media.
Science Journal of Analytical Chemistry, 2015
American Journal of Applied Chemistry, 2014
A series of three new metal (II) complexes of Schiff base were synthesized from the novel ligand ... more A series of three new metal (II) complexes of Schiff base were synthesized from the novel ligand derived from Streptomycin and Amoxicillin in stoichiometric ratio. They were characterized by elemental analysis and spectral techniques like IR, 1 H NMR, electronic spectrum and mass spectrum. IR spectral data suggested that the tetradentate ligand has coordination to metal ions through azomethine nitrogen, glycosidic oxygen and two amine nitrogens. Electronic spectral measurement indicated square planar geometry of Ni and Zn-complexes and tetrahedral geometry of Cu-complex with diamagnetic behavior. Molar conductivity measurements revealed non-electrolyte nature of the complexes where metal ions have coordination through doubly negative charged anions of the Schiff base. The thermal behavior (TGA/DTA) of the complexes was studied and kinetic parameters were determined by Coats-Redfern method. XRPD technique revealed monoclinic crystal systems for Ni-and Zn-complexes and hexagonal crystal system for Cu-complex. The possible geometries of the metal complexes with their bond length were optimized by MM2 calculations using CsChem3D Ultra-11 program package software. Antibacterial sensitivity of the ligand and its metal complexes were assayed in vitro against four bacterial pathogens viz. E. coli, B. subtilis, S. aureus and K. pneumonia by Kirby Bauer paper disc diffusion method and showed moderate to better potency.
BIBECHANA, 2010
The switching in materials is the most interesting phenomenon discovered in materials, both organ... more The switching in materials is the most interesting phenomenon discovered in materials, both organic and inorganic. The switching materials opened a large class of applications in electronics and informatics. Rotaxane is one such type of molecule which shows switching ability by the action of external stimuli either chemical or physical. Reversible structural change occurring in rotaxane due to external stimulus is described and its application in nanorecording is also studied. Keywords: CBPQT (cyclobis(paraquat-p-phenylene); TTF (tetrathiafulvalene); DNP (1,5- dioxynaphthalene)DOI: 10.3126/bibechana.v7i0.4044BIBECHANA 7 (2011) 44-48
BIBECHANA, 2012
Different Schemes for the synthesis of Schiff bases have been discussed. Solvent free synthesis b... more Different Schemes for the synthesis of Schiff bases have been discussed. Solvent free synthesis by microwave irradiation technique is observed to be rapid, more efficient and more economical and at the same time may play a pivotal role in the progress of Schiff base synthesis. Mechanism for the synthesis of Schiff bases at controlled pH range has been studied. Biological functions of metal complexes of Schiff bases have found to be increased potentiality in presence of transition metal ions. DOI: http://dx.doi.org/10.3126/bibechana.v9i0.7178 BIBECHANA 9 (2013) 75-80
Journal of Chemistry, 2015
Two new metal complexes of general formula M(Haαft)2[M =NiIIandCuII] of asymmetrical Schiff base ... more Two new metal complexes of general formula M(Haαft)2[M =NiIIandCuII] of asymmetrical Schiff base ligand (HL = Haαft) derived from amoxicillin andα-formylthiophene have been prepared and characterized by various physicochemical and spectral techniques. Molar conductance measurement indicates nonelectrolytic nature of the metal complexes. FT-IR spectral study reveals the ligation of metal ions at two different nitrogen [NN] donor sites of Haαft. FT-IR and electronic absorption spectral evidences suggest distorted tetrahedral and square planar geometry forCuIIandNiIIcomplexes, respectively. The structure optimization by molecular mechanics (MM) force field calculation through ArgusLab 4.0.1 version software also supports the concerned geometry of the complexes. The cell dimensions as suggested by XRPD study,a(6.753 Å),b(13.904 Å),c(20.122 Å),α(142.76°),β(106.580°), andγ(72.4343°) forCuIIanda(24.2547 Å),b(6.6371 Å),c(5.5047 Å) (α=β=γ= 90°) forNiIIcomplexes, are in good agreement with th...
A new Schiff base ligand AMXPC was prepared by refluxing Amoxicillin trihydrate and Pyrrole-2-car... more A new Schiff base ligand AMXPC was prepared by refluxing Amoxicillin trihydrate and Pyrrole-2-carbaldehyde in aqueous methanol solution in weak acidic medium. The metal complexes have been synthesized by using chloride salts of Copper, Cobalt and Zinc and they were characterized by analytical techniques viz: IR, 1 H NMR, TOF mass and elemental analysis. The synthesized ligand along with their metal(II) complexes were screened for their in vitro antibacterial activity against three pathogenic bacteria E. coli, B. subtilis and S. aureus, by measuring diameter of zone of inhibition in mm. Amoxicillin trihydrate was taken as control drug. The result of these studies show the strong antibacterial activity of metal(II) complexes compared to ligand and control drug.
Bioinorganic Chemistry and Applications
A novel Schiff base ligand of type HL was prepared by the condensation of amoxicillin trihydrate ... more A novel Schiff base ligand of type HL was prepared by the condensation of amoxicillin trihydrate and nicotinaldehyde. The metal complexes of Co+2, Ni+2, Cu+2, and Zn+2 were characterized and investigated by physical and spectral techniques, namely, elemental analysis, melting point, conductivity, 1H NMR, IR, UV-Vis spectra, ESR, SEM, and mass spectrometry measurements. They were further analyzed by thermal technique (TGA/DTA) to gain better insight about the thermal stability and kinetic properties of the complexes. Thermal data revealed high thermal stability and nonspontaneous nature of the decomposition steps. The Coats-Redfern method was applied to extract thermodynamic parameters to explain the kinetic behavior. The molar conductance values were relatively low, showing their nonelectrolytic nature. The powder XRD pattern revealed amorphous nature except copper complex (1c) that crystallized in the triclinic crystal system. The EPR study strongly recommends the tetrahedral geome...
A series of three new metal (II) complexes of Schiff base were synthesized from the novel ligand ... more A series of three new metal (II) complexes of Schiff base were synthesized from the novel ligand derived from Streptomycin and Amoxicillin in stoichiometric ratio. They were characterized by elemental analysis and spectral techniques like IR, 1 H NMR, electronic spectrum and mass spectrum. IR spectral data suggested that the tetradentate ligand has coordination to metal ions through azomethine nitrogen, glycosidic oxygen and two amine nitrogens. Electronic spectral measurement indicated square planar geometry of Ni and Zn-complexes and tetrahedral geometry of Cu-complex with diamagnetic behavior. Molar conductivity measurements revealed non-electrolyte nature of the complexes where metal ions have coordination through doubly negative charged anions of the Schiff base. The thermal behavior (TGA/DTA) of the complexes was studied and kinetic parameters were determined by Coats-Redfern method. XRPD technique revealed monoclinic crystal systems for Ni-and Zn-complexes and hexagonal crystal system for Cu-complex. The possible geometries of the metal complexes with their bond length were optimized by MM2 calculations using CsChem3D Ultra-11 program package software. Antibacterial sensitivity of the ligand and its metal complexes were assayed in vitro against four bacterial pathogens viz. E. coli, B. subtilis, S. aureus and K. pneumonia by Kirby Bauer paper disc diffusion method and showed moderate to better potency.
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Papers by Narendra Kr Chaudhary