Performance of graphene-zinc oxide nanocomposite coated-glassy carbon electrode in the sensitive determination of para-nitrophenol.

Graphene: zinc oxide nanocomposite (GN:ZnO NC) platform was tried for the sensitive determination of para-nitrophenol (p-NP) through the electrochemical method. ZnO nanoparticles (NPs) were synthesized by the modified wet-chemical method where in potassium hydroxide and zinc nitrate were used as precursors and starch as a stabilizing agent. A green and facile approach was applied to synthesize GN:ZnO NC in which glucose was employed as a reductant to reduce graphene-oxide to graphene in the presence of ZnO NPs. The synthesized NC was characterized using scanning and high-resolution transmission electron microscopy, energy dispersive x-ray analysis, X-ray diffraction and Raman spectroscopic techniques to examine the crystal phase, crystallinity, morphology, chemical composition and phase structure. GN:ZnO NC layer deposited over the glassy carbon electrode (GCE) was initially probed for its electrochemical performance using the standard 1 mM K3[Fe(CN)6] model complex. GN:ZnO NC modified GCE was monitored based on p-NP concentration. An enhanced current response was observed in 0.1 M phosphate buffer of pH 6.8 for the determination of p-NP in a linear working range of 0.09 × 10-6 to 21.80 × 10-6 M with a lower detection limit of 8.8 × 10-9 M employing square wave adsorptive stripping voltammetric technique at a deposition-potential and deposition-time of - 1.0 V and 300 s, respectively. This electrochemical sensor displayed very high specificity for p-NP with no observed interference from some other possible interfering substances such as 2, 4-di-NP, ortho-NP, and meta-NP. The developed strategy was useful for sensitive detection of p-NP quantity in canals/rivers and ground H2O samples with good recoveries.

Structure based molecular inhibition of Caspase-8 for treatment of multi-neurodegenerative diseases using known natural compounds.

Neurodegenerative disorders are often associated with excessive neuronal apoptosis. It is well known that apoptosis is regulated by some intracellular proteases, such as, Caspases (cysteine-dependent, aspartate-specific proteases). In fact, Caspase-8 which is an initiator caspase, has been identified as a key mediator of neuronal apoptosis. In addition, Caspase-8 is found to be coupled with the regulation of various neurodegenerative disorders including Alzheimer׳s disease (AD), Parkinson׳s disease (PD), Huntington׳s Diseases (HD) and Dentatorubral Pallidoluysian Atrophy (DRPLA). Caspase-8 inhibition may provide an effective means of treatment for multiple neurodegenerative disorders. Therefore, the present study describes the molecular interaction of some selected natural compounds with known anti neurodegenerative properties with Caspase-8. Docking between Caspase-8 and each of these compounds (separately) was performed using 'Autodock4.2'. Out of all the selected compounds, rosmarinic acid and curcumin proved to be the most potent inhibitors of Caspase-8 with binding energy (ΔG) of -7.10 Kcal/mol and -7.08 Kcal/mol, respectively. However, further in vitro and in vivo studies are needed to validate the anti-neurodegenerative potential of these compounds.

A report on biocompounds from palm fossil of India.

The occurrence of a large number of fossil woods having resemblance in anatomical features with the modern palm genus, Phoenix L in Deccan Intertrappean fossil flora of Maastrichtian-Danian age (i. e. Late Cretaceous and Earliest Tertiary (65-67 my)) indicates the most primitive record of date palm. Present discovery of biocompounds from fossil wood of Phoenix collected from Deccan Intertrappean having affinity with the biocompounds known from modern plant further exemplify the earliest documentation of Phoenix in Indian peninsula.

Design, synthesis, evaluation and thermodynamics of 1-substituted pyridylimidazo[1,5-a]pyridine derivatives as cysteine protease inhibitors.

Targeting papain family cysteine proteases is one of the novel strategies in the development of chemotherapy for a number of diseases. Novel cysteine protease inhibitors derived from 1-pyridylimidazo[1,5-a]pyridine representing pharmacologically important class of compounds are being reported here for the first time. The derivatives were initially designed and screened in silico by molecular docking studies against papain to explore the possible mode of action. The molecular interaction between the compounds and cysteine protease (papain) was found to be very similar to the interactions observed with the respective epoxide inhibitor (E-64c) of papain. Subsequently, compounds were synthesized to validate their efficacy in wet lab experiments. When characterized kinetically, these compounds show their Ki and IC50 values in the range of 13.75 to 99.30 µM and 13.40 to 96.50 µM, respectively. The thermodynamics studies suggest their binding with papain hydrophobically and entropically driven. These inhibitors also inhibit the growth of clinically important different types of Gram positive and Gram negative bacteria having MIC50 values in the range of 0.6-1.4 µg/ml. Based on Lipinski's rule of Five, we also propose these compounds as potent antibacterial prodrugs. The most active antibacterial compound was found to be 1-(2-pyridyl)-3-(2-hydroxyphenyl)imidazo[1,5-a]pyridine (3a).

Predicted binding of certain antifilarial compounds with glutathione-S-transferase of human Filariids.

UNLABELLED: : Glutathione-S-transferase is a major phase-II detoxification enzyme in parasitic helminthes. Previous research highlights the importance of GSTs in the establishment of chronic infections in cytotoxic microenvironments. Filarial nematodes depend on these detoxification enzymes for their survival in the host. GST plays an important role in filariasis and other diseases. GST from W.bancrofti and B.malayi are very much different from human GST. This structural difference makes GST potential chemotherapeutic targets for antifilarial treatment. In this study we have checked the efficacy of some well known antifilarial compounds against GST from B.malayi and W.bancrofti. The structure of BmGST was modeled using modeller9v10 and was submitted to PMDB. Molecular docking study reveals arbindazole to be the most potent compounds against GST from both the filarial parasites. Role of some residues playing important role in the binding of compounds within the active site of GST has also been revealed in the present study. The BmGST and WbGST structural information and docking studies could aid in screening new antifilarials or selective inhibitors for chemotherapy against filariasis. ABBREVIATIONS: GST - Glutathione-S-transferase, Bm - Brugia malayi, Wb - Wuchereria bancrofti.