Browsing by Author "Ansari, A"

Now showing 1 - 9 of 9
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    Analyzing the emerging patterns of SARS‐CoV‐2 Omicron subvariants for the development of next‐gen vaccine: An observational study
    (2023-09) Mohapatra, RK; Mishra, S; Kandi, V; Branda, F; Ansari, A
    Background and Aim: Understanding the prevalence and impact of SARS‐CoV‐2 variants has assumed paramount importance. This study statistically analyzed to effectively track the emergence and spread of the variants and highlights the importance of such investigations in developing potential next‐gen vaccine to combat the continuously emerging Omicron subvariants. Methods: Transmission fitness advantage and effective reproductive number (Re)of epidemiologically relevant SARS‐CoV‐2 sublineages through time during the study period based on the GISAID data were estimated. Results: The analyses covered the period from January to June 2023 around an array of sequenced samples. The dominance of the XBB variant strain, accounting for approximately 57.63% of the cases, was identified during the timeframe. XBB.1.5 exhibited 37.95% prevalence rate from March to June 2023. Multiple variants showed considerable global influence throughout the study, as sporadically documented. Notably, the XBB variant demonstrated an estimated relative 28% weekly growth advantage compared with others. Numerous variants were resistant to the over‐the‐counter vaccines and breakthrough infections were reported. Similarly, the efficacy of mAB‐based therapy appeared limited. However, it's important to underscore the perceived benefits of these preventive and therapeutic measures were restricted to specific variants. Conclusion: Given the observed trends, a comprehensive next‐gen vaccine coupled with an advanced vaccination strategy could be a potential panacea in the fight against the pandemic. The findings suggest that targeted vaccine development could be an effective strategy to prevent infections. The study also highlights the need of global collaborations to rapidly develop and distribute the vaccines to ensure global human health.
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    Comparison of the binding energies of approved mpox drugs and phytochemicals through molecular docking, molecular dynamics simulation, and ADMET studies: An in silico approach
    (2023-09) Kumar, M; Ansari, A
    The mpox (previously monkeypox) outbreak in more than 100 non-endemic countries in 2022 posed a serious global health concern. Mpox is emerging as a global public health threat from a seemingly neglected disease. A42R profilin-like protein from mpox virus (PDB ID: 4QWO) could be a preferred target lead. The binding affinity of commonly used drugs/mAbs (tecovirimat, brincidofovir, cidofovir) for A42R profilin-like protein was examined in silico through molecular docking. Further, the results were com pared with those of the phytochemicals curcumin, rutin, and theaflavin. Tecovirimat ( 7.31 kcal/mol, IC50 = 4.39 lM) and theaflavin ( 6.99 kcal/mol, IC50 = 7.54 lM) had the highest affinities. Molecular dynamics simulation of the theaflavin–4QWO complex was performed to ascertain the stability of ligand–protein interactions in natural charge, molecular electrostatic potential, and frontier molecular orbital analyses. The predicted QSAR and pharmacokinetic properties of all compounds were evaluated to find a suitable candidate for designing and developing new drugs. The evaluated log P values for brin cidofovir and tecovirimat were higher than those of the other drugs in the QSAR study. Theaflavin had an impressive log P of 4.77, which hints at its high biological activity. The findings recommend further in vitro experimental validation to develop potential low-cost mpox therapies.
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    An efficient synthesis towards the core of Crinipellin: TD-DFT and docking studies
    (2021-01) Sahu, R; Mohapatra, R; Al-Resayes, S; Das, D; Parhie, P; Rahman, S; Pintilie, L; Kumar, M; Azam, M; Ansari, A
    In this present report, we are describing a novel route for the synthesis of the tetracyclic ring systems, a common core of crinipellin, via oxidative dearomatization, cycloaddition and oxa di-pi-methane rearrangement. We are also concerned to explore a route to tetracyclic core (1e)of Crinipellin and tricyclic core (1g) of Allicaol B through intermolecular diels alder reaction and pho tochemically 1,2 acyl shift. Moreover, docking study of compound 13 and 16 is investigated against AcrB multidrug efflux pump of Escherichia coli (PDB ID: 1T9U), main protease of SARS COV-2 (PDB ID: 6W63), DNA gyrase of Streptococcus pneumonia (PDB ID: 4Z2C), human estrogen receptor alpha (PDB ID: 3ERT), human lanosterol 14-alpha-demethylase (CYP51)(PDB ID: 3JUS) and cyclooxygenase-2 (Prostaglandin Synthase-2) (PDB ID: 1CX2). The obtained results are important for the exploitation of the therapeutic potential of these derivatives as antimicrobial, antiviral, anticancer, antifungal or anti-inflammatory agents. In addition, TD-DFT studies of the compounds are also carried out.
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    How to identify a smoker: a slient crystallographic
    (2021-04) Iman, K; Ahamad, M; Monika; Ansari, A
    There is an increasing demand for monitoring environmental pollutants and the control requires new sensing materials with better sensitivity, selectivity and reliability. In this study, a series of Co7 clusters incorporating various flexible polyhydroxyamine ligands are explored, with the first report of thiocyanate recognition triggered by crystal formation using a Co7 crystal (1). For this, we have fortunately synthesized three new mixed metal Co7 clusters with fascinating structural features. The clusters were characterized by spectroscopic and single crystal X-ray diffraction methods and later by DFT calculations. Due to its better emission spectrum, 1 was further utilized for evaluating its sensing ability towards various anions in water. Surprisingly, 1 shows better quenching ability towards the recognition of SCN with a better binding constant. The luminescence quenching towards SCN detection was further verified by the single crystal method, HSAB principle (symbiosis) and theoretical calculations such as DFT studies. The SCXRD data clearly suggest that the Co7 (1) can be converted into Co14 (1a) by direct reaction with NaSCN under ambient conditions. Besides the soft/hard acid–base concept (symbiosis), the energies of formation, and Co–NCS and Co–OH2 bond energies (as unravelled by DFT) are responsible for this transformation. Therefore, 1 can be used as a selective and sensitive sensor for the detection of thiocyanate anions based on the fluorescence amplification and quenching method. Further, the designed cluster has also been utilized to detect anions in human blood samples to differentiate a smoker and a non-smoker. It has been concluded that the samples of smokers have a high degree of thiocyanate ( 12 or 9.5 mg L 1) in comparison to those of non-smokers (2–3mgL 1). Thus, this kind of cluster material has high potentiality in the field of bio-medical science in future endeavours for identification of the extent of thiocyanate content in smokers.
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    Rebound or Cage Escape? The Role of the Rebound Barrier for the Reactivity of Non-Heme High-Valent FeIV=O species
    (2023) Kumar, R; Ansari, A; Comba, P
    Owing to their high reactivity and selectivity, variations in the spin ground state and a range of possible pathways, high-valent FeIV=O species are popular models with potential bioinspired applications. An interesting example of a structure–reactivity pattern is the detailed study with five nonheme amine-pyridine pentadentate ligand FeIV=O species, including N4py: [(L1 )FeIV= O]2+ (1), bntpen: [(L2 )FeIV=O]2+ (2), py2tacn: [(L3 )FeIV=O]2+ (3), and two isomeric bispidine derivatives: [(L4 )FeIV=O]2+ (4) and [(L5 )FeIV=O]2+ (5). In this set, the order of increasing reactivity in the hydroxylation of cyclohexane differs from that with cyclohexadiene as substrate. A comprehensive DFT, ab initio CASSCF/NEVPT2 and DLPNO-CCSD(T) study is presented to untangle the observed patterns. These are well reproduced when both activation barriers for the C H abstraction and the OH rebound are taken into account. An MO, NBO and deformation energy analysis reveals the importance of π(pyr) ! π*xz(FeIII-OH) electron donation for weakening the FeIII-OH bond and thus reducing the rebound barrier. This requires that pyridine rings are oriented perpendicularly to the FeIII-OH bond and this is a subtle but crucial point in ligand design for non heme iron alkane hydroxylation.
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