Inhibitory efficacy of RNA virus drugs against SARS-CoV-2 proteins: An extensive study.

Herein we have made a comprehensive analysis of inhibitory efficacy of 16 RNA virus drugs against RdRp, Mpro and PLpro proteins of SARS-CoV-2. Analysis of docked conformation revealed that Baloxavir marboxil (BMX) corresponds to the highest binding energy. Analysis of residue confirmed that BMX strongly interact with these three proteins involving H-bonding, ionic as well as hydrophobic interactions. Molecular dynamics simulation and analysis of parameters like RMSD, RMSF, binding energy confirmed noticeable conformational alternation with these proteins with makeable effect on RdRp. The potentially inhibitory action of BMX against these three proteins suggests the inhibition of overall transcription process of SARS-CoV-2. These observation along with the recently observed inhibitory action of BMX on influenza with clinically proven no side effects emphasizes to uncover the role of BMX by in-vitro and in-vivo analysis.

Comparative study of the efficiency of silicon carbide, boron nitride and carbon nanotube to deliver cancerous drug, azacitidine: A DFT study.

Herein we have made a comparative study of the efficiency of three different nanotubes viz. Carbon nanotube (CNT), boron nitride nanotube (BNNT) and silicon carbide nanotube (SiCNT) to deliver the cancerous drug, Azacitidine (AZD). The atomistic description of the encapsulation process of AZD in these nanotubes has been analyzed by evaluating parameters like adsorption energy, electrostatic potential map, reduced density gradient (RDG). Higher adsorption energy of AZD with BNNT (-0.66eV), SiCNT (-0.92eV) compared to CNT (-0.56eV) confirms stronger binding affinity of the drug for the former than the later. Charge density and electrostatic potential map suggest that charge separation involving BNNT and CNT is more prominent than SiCNT. Evaluation of different thermodynamic parameters like Gibbs free energy, enthalpy change revealed that the overall encapsulation process is spontaneous and exothermic in nature and much favorable with BNNT and SiCNT. Stabilizing interactions of the drug with BNNT and SiCNT has been confirmed from RDG analysis. ADMP molecular dynamics simulation supports that the encapsulation process of the drug within the NT at room temperature. These results open up unlimited opportunities for the applications of these NTs as a drug delivery system in the field of nanomedicine.

Anti-enteric efficacy and mode of action of tridecanoic acid methyl ester isolated from Monochoria hastata (L.) Solms leaf.

Monochoria hastata (L.) Solms (family Pontederiaceae), an ethnomedicinal aquatic herb, is used to remedy several gastrointestinal diseases by various ethnic groups in India. The present study aimed to purify and characterize the antibacterial active ingredient against gastrointestinal (GI) diseases and its mode of action using in vitro experimental models. The active lead molecule in the ethyl acetate extract (EA-Mh) fraction has been purified and characterized through high-performance liquid chromatography (HPLC), proton nuclear magnetic resonance (1H NMR), and electrospray ionization mass spectrometry (ESI-MS) methods. The anti-enteric efficacy has been evaluated against enteropathogenic Gram-positive and Gram-negative bacteria by minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), lactate dehydrogenase (LDH), and scanning electron microscopy (SEM) studies. The synergistic and antagonistic studies were done on E. coli MTCC 723 using standard antibiotics (ampicillin and kanamycin, final conc. 50 µg/ml) in a sterilized 96-well micro-plate, incubated at 37 ℃ for 24 h. The chromatographic and spectroscopic analyses revealed the presence of tridecanoic acid methyl ester (TAME) in the bioactive fraction. The compound causes significant extracellular leakage activity by disrupting cellular morphology in the Enterococcus faecalis MCC 2041 T and Salmonella enterica serovar Typhimurium MTCC 98, at a dose of 375 µg/ml and 750 µg/ml, respectively. The SEM study shows a significant rupturing of E. coli and E. faecalis cells due to TAME induced autolysis. It has synergistic activity with ampicillin. The in silico molecular docking through the AutoDock Vina 4.2 and GROMACS (ver. 5.1) Charmm27 force field results showed that the TAME had a strong binding affinity Escherichia coli DNA Gyrase B (PDB ID: 5l3j.pdb) protein and caused conformational changes. Thus, the manuscript reports the first time on the characterization of TAME from this plant with a detailed antibacterial mode of action studies.

Study of Thermometry in Two-Dimensional Sb2Te3 from Temperature-Dependent Raman Spectroscopy.

Discovery of two-dimensional (2D) topological insulators (TIs) demonstrates tremendous potential in the field of thermoelectric since the last decade. Here, we have synthesized 2D TI, Sb2Te3 of various thicknesses in the range 65-400 nm using mechanical exfoliation and studied temperature coefficient in the range 100-300 K using micro-Raman spectroscopy. The temperature dependence of the peak position and line width of phonon modes have been analyzed to determine the temperature coefficient, which is found to be in the order of 10-2 cm-1/K, and it decreases with a decrease in Sb2Te3 thickness. Such low-temperature coefficient would favor to achieve a high figure of merit (ZT) and pave the way to use this material as an excellent candidate for thermoelectric materials. We have estimated the thermal conductivity of Sb2Te3 flake with the thickness of 115 nm supported on 300-nm SiO2/Si substrate which is found to be ~ 10 W/m-K. The slightly higher thermal conductivity value suggests that the supporting substrate significantly affects the heat dissipation of the Sb2Te3 flake.

Catalytic Use toward the Redox Reaction of Toxic Industrial Wastes in Innocuous Aqueous Medium and Antibacterial Activity of Novel Cu x Ag x Zn1-2x O Nanocomposites.

In this work, we report the redox properties in organic catalytic transformation and antibacterial activity of novel Cu x Ag x Zn1-2x O nanocomposites. Cu- and Ag-doped ZnO [Cu x Ag x Zn1-2x O (x = 0.1)] (CAZ), Cu-doped ZnO [Cu x Zn1-x O (x = 0.1)] (CZ), and Ag-doped ZnO [Ag x Zn1-x O (x = 0.1)] (AZ) were prepared via a chemical co-precipitation method. The synthesized nanocomposites were characterized using different spectroscopic techniques. The catalytic activity of CAZ, CZ, and AZ was examined for the reduction of 4-nitrophenol (4-NP) and 4-nitroaniline (4-NA) in the presence of NaBH4 in an aqueous medium. The photocatalytic oxidation efficiency of these catalysts was also observed against naphthol orange (NO) under ultraviolet light. It was found that the catalytic reduction and oxidation efficiency of CAZ is higher than that of CZ and AZ in 4-NP/4-NA and NO in a water solvent, respectively. The antibacterial property of CAZ was also studied against Gram-positive and Gram-negative bacteria by agar well diffusion and the minimum inhibitory concentration methods. It was found that CAZ shows better antimicrobial activity compared to its parental Cu(NO3)2·3H2O, AgNO3, and ZnO. Therefore, the incorporation of Cu and Ag into ZnO increases its catalytic and antimicrobial activity remarkably. Fourier-transform infrared and X-ray diffraction (XRD) studies of CAZ indicate the incorporation of Cu and Ag into the lattice of ZnO. The phase structure of CAZ was wurtzite hexagonal, and the average crystallite size was 93 ± 1 nm measured from XRD. The average grain size and particle size of CAZ were found to be 200 and 100 ± 5 nm originating from SEM and transmission electron microscopy studies, respectively. The optical energy band gap of CAZ is 3.15 eV, which supports the excellent photocatalyst under UV light. CAZ also exhibits good agreement for photoluminescence properties with a high intensity peak at 571 nm, indicating surface oxygen vacancies and defects which might be responsible for higher photocatalytic activity compared to others. The nanocomposite shows excellent reusability without any significant loss of activity.

Physicochemical and elemental studies of Hydrocotyle javanica Thunb.for standardization as herbal drug

Objective:To explore the leaves of Hydrocotylejavanica Thunb.as a source of safe and effective antibacterial herbal medicine.Methods:The standardization was validated by stepwise physicochemical studies,element analysis,determination of ash values,fluorescence analysis,assessment of moisture content,extractive values in different solvent systems and extraction methods.Heavy metal contents,mineral and element contents were analysed by atomic absorption spectrophotometry,inductively coupled plasma-mass spectrometer and CHNS/O analyser,respectively.Results:The methanol extract of the folklore medicinal plant having antibacterial efficacy contained flavonoids and phenolic OH groups.The ICP multi standard indicated the presence of three major compounds with molecular mass of 161 190 and 221 Da.Heavy metals viz.lead,mercury and copper content were 4.38 ppm,＜ 0.05 ppm and 24.70 ppm,respectively.Minerals content of calcium,phosphorus,potassium and iron were 1 190.94 mg/100 g,375.57 mg/100 g,2820 mg/100 g and 340.20 mg/100 g of plant sample,respectively.Elements like carbon,hydrogen,nitrogen and sulphur contents were 38.18％,5.67％,2.23％ and 0.51％,respectively.Heavy metal profile of the tested plant was within the permissible limits of the regulatory authorities.Conclusions:Hence the present physicochemical and elements studies reveals that the plant Hydrocotylejavanica Thunb.could be a potent source of herbal preparation as well as a safe and novel synthetic antibacterial drug.