https://repository.auw.edu.bd/handle/123456789/785 2026-05-13T16:56:58Z https://repository.auw.edu.bd/handle/123456789/962 Computational Studies on T2Rs Agonist-Based Anti–COVID-19 Drug Design Selvakumar Paulraj, Mosae The expeditious and world pandemic viral disease of new coronavirus (SARS-CoV-2) has formed a prompt urgency to discover auspicious target-based ligand for the treatment of COVID-19. Symptoms of novel coronavirus disease (COVID-19) typically include dry cough, fever, and shortness of breath. Recent studies on many COVID-19 patients in Italy and the United Kingdom found increasing anosmia and ageusia among the COVID- 19-infected patients. SARS-CoV-2 possibly infects neurons in the nasal passage and disrupts the senses of smell and taste, like other coronaviruses, such as SARS-CoV and MERS-CoV that could target the central nervous system. Developing a drug based on the T2Rs might be of better understanding and worth finding better molecules to act against COVID-19. In this research, we have taken a taste receptor agonist molecule to find a better core molecule that may act as the best resource to design a drug or corresponding derivatives. Based on the computational docking studies, the antibiotic tobramycin showed the best interaction against 6LU7 COVID-19 main protease. Aromatic carbonyl functional groups of the molecule established intermolecular hydrogen bonding interaction with GLN189 amino acid and it showed the two strongest carbonyl interactions with receptor protein resulting in a glide score of −11.159. To conclude, depending on the molecular recognition of the GPCR proteins, the agonist molecule can be recognized to represent the cell secondary mechanism; thus, it provides enough confidence to design a suitable molecule based on the tobramycin drug. 2021-01-01T00:00:00Z https://repository.auw.edu.bd/handle/123456789/961 Tuning of Photoluminescence and Antibacterial Properties of ZnO Nanoparticles through Sr Doping for Biomedical Applications Selvakumar Paulraj, Mosae Sr-doped ZnO nanoparticles have been synthesized using a soft chemical method. The doping ratio of Sr is varied in the range of 0 at.%, 3 at.%, and 5 at.% to 7 at.%. X-ray diffractograms revealed that the samples had hexagonal (wurtzite) structure without a trace of any mixed phase. The average crystallite size of the nanoparticles (NPs) ranged from 39 to 46 nm. The average crystallite size was increased for the initial doping (3 at.%) of Sr ions, and further increase in the doping ratio reduced the particle size due to some distortion produced in the lattice. The surface morphology of the samples and structure of the NPs were investigated using FESEM (Field Emission Scanning Electron Microscopy) and TEM (Transmission Electron Microscopy) pictures, respectively. EDX (energy-dispersive X-ray) spectroscopy confirmed the presence of strontium (Sr) in the host lattice. Photoluminescence and X-ray diffraction confirmed that the dopant ions replace some of the lattice zinc ions and that Sr2+ and Sr3+ ions coexist in the ZnO lattice. The Sr-doped ZnO exhibited violet and blue luminescence spectra at 408 nm and 492 nm, respectively. ZnO : Sr nanoparticles showed increased antibacterial activity against one gram-positive as well as one gram-negative bacteria. 2021-01-01T00:00:00Z https://repository.auw.edu.bd/handle/123456789/960 Green Synthesis of Silver Nanoparticles using the Leaf Extract of Filicium decipiens and its Anti-Microbial Activity Selvakumar, Mosae Silver nanoparticles has been used since ages; even now it is used in almost all areas like medicine, textiles, industries, cosmetics, purification and dying. There are many approaches to synthesize silver nanoparticles. However, these approaches are either harmful to the environment or highly expensive. An attempt has been made in this eco-friendly approach towards the green synthesis of silver nanoparticles (AgNPs) using the leaves of Filicium decipiens. Characterization of as- synthesized AgNPs were done using UV-Visible spectroscopy and Fluorescence spectroscopy which confirmed the formation of AgNPs. Scanning Electron Microscope (SEM) confirmed its rounded shape and X-ray diffraction (XRD) determined its crystalline nature as face centered cubic structure. Furthermore, Dynamic Light Scattering (DLS) was also done in order to know the average diameter and zeta potential of AgNPs. However, it did not show potential results due to the aggregates formed during the green synthesis of AgNPs. In addition to this, anti-microbial test against bacteria such as gram negative (Escherichia Coli) and gram positive (Bacillus subtilis) were done using well-diffusion method and also its application of anti- microbial activity was tested over fabric to understand its application in textile industries. In both the cases, AgNPs showed more efficiency in gram negative than gram-positive bacteria. 2021-01-01T00:00:00Z https://repository.auw.edu.bd/handle/123456789/958 Structural, Morphological, Optical, and Antibacterial Activities of Zinc Oxide Nanopowders: A Comparative Study of Green and Soft Chemical Synthesis Saravanakumar, K. Zinc oxide, a well-known inorganic metal oxide in nanoparticle form, has outstanding antibacterial properties. In this work, the authors focus on determining ZnO nanoparticles’ structural, optical, and antibacterial activity. A simple soft chemical route synthesizes C-ZnO nanoparticles chemically, while the green synthesis method is used to prepare G-ZnO nanoparticles. Ocimum tenuiorum leaf extract was used to prepare G-ZnO nanopowders. ese samples are investigated and compared in terms of their structural, morphological, optical, and antibacterial properties. According to XRD investigations, the synthesized ZnO nano- powders possess a hexagonal structure. e particle size of G-ZnO is smaller than that of C-ZnO nanoparticles. e XPS result revealed the binding and interactions between molecules. e FTIR study conrmed the presence of molecules and their vi- brations. UV-vis-DRS spectroscopy was used to investigate optical properties such as reectance and band gap. e grain size of the G-ZnO nanopowders was decreased, and oxygen vacancy was produced. e antibacterial eciency of plant extracts against two dierent bacterial strains, S. aureus (Gram-positive) and E.coli (Gram-negative), has been studied and reported. 2022-01-01T00:00:00Z