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Paparisva A.,Aristotle University of Thessaloniki | Geronikaki A.,Aristotle University of Thessaloniki | Kamoutsis C.,University of Patras | Ciric A.,University of Belgrade | And 6 more authors.
Arabian Journal of Chemistry

As a part of our ongoing studies in developing new derivatives as antimicrobial agents we describe the synthesis of novel substituted 5-benzylideno-2-adamantylthiazol[3,2-b][1,2,4]triazol-6(5H)ones.The twenty-five newly synthesized compounds were tested for their antimicrobial and antifungal activity. All compounds have shown antibacterial properties with compounds . 1-9 showing the lowest activity, followed by compounds . 10-14 while compounds . 15-25 the highest antibacterial activity. Specific compounds appeared to be more active than ampicillin in most studied strains and in some cases more active than streptomycin. Antifungal activity in most cases also was better than that of reference drugs ketoconazole and bifonazole. Elucidating the relation of molecular properties to antimicrobial activity as well as generation of pharmacophore model for antifungal activity of two fungal species . Aspergillus fumigatus and . Candida albicans were performed. © 2016 The Authors. Source

Saxena M.,Amity University | Bhunia S.S.,Global Institute of Pharmaceutical Education and Research | Saxena A.K.,CSIR - Central Electrochemical Research Institute
SAR and QSAR in Environmental Research

The human histamine H2 receptor (hH2HR) is a G-protein coupled receptor protein with seven transmembrane (TM)-spanning helices primarily involved in regulation of gastric acid secretion. Antagonists targeting hH2HR are useful in the treatment of hyperacidic conditions such as peptic ulcers, gastresophageal reflux disease and gastrointestinal bleeding. We have previously reported the antagonism of 2-substituted pyrazinopyridoindoles at the human histamine H1 receptor and mode of binding of these compounds at the hH1HR using in silico methods. Interestingly, some of the compounds in the series also showed promising activity towards hH2HR that prompted us to investigate the mode of binding of these compounds at hH2HR. In the absence of the crystal structure of hH2HR a homology model has been constructed using multiple sequence alignment, using the X-ray crystal structures of Turkey β1-adrenergic receptor (tβ1AR), Human histamine H1 receptor (hH1HR), Human β2-adrenergic receptor (hβ2AR) and Human D3 dopamine receptor (hD3R). The important residues for binding were depicted in TMIII, TMV, TMVI and TMVII by the homology modelled hH2HR for 2-substituted pyrazinopyridoindoles. A comparative study for deducing the selectivity regarding the binding towards hH1HR and hH2HR has been carried out, which may be useful in designing of selective hH1HR/hH2HR antagonists in these classes of compounds. © 2015 Taylor & Francis. Source

Saxena A.K.,CSIR - Central Electrochemical Research Institute | Devillers J.,CTIS | Bhunia S.S.,Global Institute of Pharmaceutical Education and Research | Bro E.,National Game and Wildlife Institute ONCFS
SAR and QSAR in Environmental Research

The potential effects of pesticides and their metabolites on the endocrine system are of major concern to wildlife and human health. In this context, the azole pesticides have earned special attention due to their cytochrome P450 aromatase inhibition potential. Cytochrome P450 aromatase (CYP19) catalyses the conversion of androstenedione and testosterone into oestrone and oestradiol, respectively. Thus, aromatase modulates the oestrogenic balance essential not only for females, but also for male physiology, including gonadal function. Its inhibition affects reproductive organs, fertility and sexual behaviour in humans and wildlife species. Several studies have shown that azole pesticides are able to inhibit human and fish aromatases but the information on birds is lacking. Consequently, it appeared to be of interest to estimate the aromatase inhibition of azoles in three different avian species, namely Gallus gallus, Coturnix coturnix japonica and Taeniopygia guttata. In the absence of the crystal structure of the aromatase enzyme in these bird species, homology models for the individual avian species were constructed using the crystal structure of human aromatase (hAr) (pdb: 3EQM) that showed high sequence similarity for G. gallus (82.0%), T. guttata (81.9%) and C. japonica (81.2%). A homology model with Oncorhynchus mykiss (81.9%) was also designed for comparison purpose. The homology-modelled aromatase for each avian and fish species and crystal structure of human aromatase were selected for docking 46 structurally diverse azoles and related compounds. We showed that the docking behaviour of the chemicals on the different aromatases was broadly the same. We also demonstrated that there was an acceptable level of correlation between the binding score values and the available aromatase inhibition data. This means that the homology models derived on bird and fish species can be used to approximate the potential inhibitory effects of azoles on their aromatase. © 2015 The Author(s). Published by Taylor & Francis. Source

Kumar K.,NIMS University | Kumar K.,Global Institute of Pharmaceutical Education and Research | Rai A.K.,Pranveer Singh Institute of Technology
Tropical Journal of Pharmaceutical Research

Purpose: To prepare and evaluate floating microspheres of curcumin for prolonged gastric residence time and increased drug bioavailability. Methods: Floating microsphere were prepared by emulsion solvent diffusion method, using hydroxylpropyl methylcellulose (HPMC), ethyl cellulose (EC), Eudragit S 100 polymer in varying ratios. Ethanol/dichloromethane blend was used as solvent in a ratio of 1:1. The floating microspheres were evaluated for flow properties, particle size, incorporation efficiency, as well as in-vitro floatability and drug release. The shape and surface morphology of the microspheres were characterised by optical and scanning electron microscopy. Result: The floating microspheres showed particle size, buoyancy, drug entrapment efficiency and yield in the ranges of 251 - 387 μm, 74.6 - 90.6 %, and 72.6 - 83.5 %, and 45.5 - 82.0 %, respectively. Maximum drug release after 20 h was 47.1, 55.7, 69.4 and 81.3 % for formulations F1, F2, F3 and F4, respectively. Scanning electron micrographs indicate pores both on the surface and interior of the microspheres. Conclusion: The developed curcumin microsphere system is a promising floating drug delivery system for oral sustained administration of curcumin. © Pharmacotherapy Group. Source

Baig M.H.,Aligarh Muslim University | Baig M.H.,Yeungnam University | Balaramnavar V.M.,Global Institute of Pharmaceutical Education and Research | Wadhwa G.,Government of India | Khan A.U.,Aligarh Muslim University
Biotechnology and Applied Biochemistry

TEM and SHV are class-A-type β-lactamases commonly found in Escherichia coli and Klebsiella pneumoniae. Previous studies reported S130G and K234R mutations in SHVs to be 41- and 10-fold more resistant toward clavulanic acid than SHV-1, respectively, whereas TEM S130G and R244S also showed the same level of resistance. These selected mutants confer higher level of resistance against clavulanic acid. They also show little susceptibility against other commercially available β-lactamase inhibitors. In this study, we have used docking-based virtual screening approach in order to screen potential inhibitors against some of the major resistant mutants of SHV and TEM types β-lactamase. Two different inhibitor-resistant mutants from SHV and TEM were selected. Moreover, we have retained the active site water molecules within each enzyme. Active site water molecules were placed within modeled structure of the mutant whose structure was unavailable with protein databank. The novelty of this work lies in the use of multilayer virtual screening approach for the prediction of best and accurate results. We are reporting five inhibitors on the basis of their efficacy against all the selected resistant mutants. These inhibitors were selected on the basis of their binding efficacies and pharmacophore features. © 2015 International Union of Biochemistry and Molecular Biology, Inc. Source

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