Pawan Kaur

Biogenesis of copper nanoparticles using peel extract of Punica granatum and their antimicrobial activity against opportunistic pathogens

ABSTRACT Copper nanoparticles (CuNPs) were biologically synthesized using peel extract of Punica granatum as reducing agent as well as capping agent. On treatment of aqueous solutions of CuSO4·5H2O with peel extract of P. granatum, stable CuNPs were formed. UV-Visible spectrophotometer analysis confirmed the formation of CuNPs. The synthesized nanoparticles were characterized with Fourier transform infrared spectroscopy, particles size analyzer and transmission electron microscopy (TEM). The electron microscopy analysis of CuNPs indicated that they ranged in size from 15 to 20 nm. The biologically synthesized CuNPs demonstrated high antibacterial activity against opportunistic pathogens, that is, Micrococcus luteus MTCC 1809, Pseudomonas aeruginosa MTCC 424, Salmonella enterica MTCC 1253 and Enterobactor aerogenes MTCC 2823 in vitro. Nanoparticles synthesized biologically using plant extracts have the potential to serve as possible ecofriendly alternatives to chemical and physical methods for biomedical applications and research.! GRAPHICAL ABSTRACT

Interaction Of ZnO Nanoparticles With Food Borne Pathogens Escherichia coli DH5α and Staphylococcus aureus 5021 & Their Bactericidal Efficacy

Bactericidal activity of ZnO nanoparticles (np) against the food borne pathogens E. coli DH5α (Gram−ve) and & S. aureus 5021 (Gram+ve), and the mechanism of their interaction with target microbes was studied. Bactericidal activity of ZnO np was attributed to disruption of cell membrane causing cytoplasmic leakage, which was measured by quantifying the leakage of nucleic acids, proteins and K+ ions from the cells using UV‐VIS Spectrophotometry and Atomic Absorption Spectrophotometry, respectively. Cell membrane disruption was observed through TEM. It is proposed that both the abrasiveness and the surface oxygen species of ZnO np are responsible for their biocidal properties.

Regioselective synthesis and antimicrobial evaluation of some thioether–amide linked 1,4-disubstituted 1,2,3-triazoles

ABSTRACT A series of 1,4-disubstituted 1,2,3-triazoles having thioether as well as amide linkage were synthesized from aryl(prop-2-yn-1-yl)sulfanes and 2-azido-N-substituted acetamides through Cu(I) catalyzed click reaction. Structures of newly synthesized compounds (3a–3x) were confirmed by spectral techniques like FTIR, 1H NMR, 13C NMR, and HRMS. The synthesized triazoles were evaluated for in vitro antimicrobial activity against Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus, Candida albicans, and Aspergillus niger. Compounds 3m and 3q displayed appreciable broad spectrum antimicrobial activity against tested microbial strains. The nanoformulations of compounds 3m and 3q were also prepared and examined against one bacterial strain and one fungal strain. GRAPHICAL ABSTRACT

Plant Biotechnology: Recent Advancements and Developments

Continuous development in biotechnological techniques has led to major breakthrough discoveries in life sciences, one of which is the finding of a particular class of small RNA molecules known as microRNAs (miRNA). miRNAs have been found to regulate various biological activities in all life forms. Though plant miRNAs were discovered later than animal miRNAs, these have been found to reveal remarkable importance in gene regulation during plant development as well as toward responding to any stimuli. Unraveling the entire mystery of these small molecules is the first step to gaining a better understanding of their function. Initially, miRNAs were identified largely by experimental techniques like forward genetic screening, cloning, and microarray, but these techniques were expensive, more time-consuming, and unable to reveal poorly expressed RNA molecules. Advances in computational tools, made during the last decade, have done wonders in miRNA research work. Many novel miRNAs were discovered using these approaches in plant systems, though confirmation requires experimental validation. In this chapter, an effort has been made to understand the characteristic features of plant miRNA compared to animal miRNAs and to review the recent advances in various computational tools made for identification of plant miRNAs.