Browsing by Author "Prashant K. Sharma"

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Examining dye degradation and antibacterial properties of organically induced α-MoO3 nanoparticles, their uptake and phytotoxicity in rice seedlings
(Elsevier B.V., 2020) Prashant K. Sharma; A.S. Raghubanshi; Kavita Shah
A thermodynamically stable, organically induced α-MoO3 nanoparticles (NPs) consisting of orthorhombic units were synthesized and investigated for its photocatalytic activity in presence of visible light and for antibacterial properties. The XRD studies confirmed the formation of crystalline α-MoO3-NPs. HRTEM revealed its sheet morphology with 21.34 nm of crystallite size. The α-MoO3-NPs had dual optical band gap of 1.67 eV and 2.22 eV in UV Diffuse Reflectance Spectra (UV-DRS). In presence of LED light (12 W) and absence of an oxidizing agent the exhibits strong photocatalytic degradation of both cationic (Methylene Blue) and anionic (Eosin Yellow) dyes with 99 % and 94 % removal efficiency, respectively. The α-MoO3-NPs exhibit antibacterial activity towards microorganisms of health importance viz. Gram positive (B. cereus) and Gram negative (E. coli) at low concentration of 100 mg/l. Uptake, translocation and bioaccumulation of α-MoO3-NPs when studied in rice seedling cv HUR3022 at 15 days of growth revealed the uptake of Mo be 7.3 ppm in roots and 4.5 ppm in shoots under 100 mg/l α-MoO3-NPs treatment. More translocation of Mo from root to shoot upon application of organically induced α-MoO3-NPs were noted however, the translocation factor was 0.6, almost similar to that in controls. The translocation and bioaccumulation factor both were below 1.0 suggesting novel α-MoO3-NPs to be non-phytotoxic and environmentally safe. The synthesized α-MoO3-NPs via simple steps and their remarkable photocatalytic properties, reusability, antibacterial activity and safe for environment makes them a promising nanomaterial for varied applications including membrane technology, water treatment, control of bacterial infections and in agriculture. © 2020 Elsevier B.V.
Examining structural analogs of elvitegravir as potential inhibitors of HIV-1 integrase
(Springer-Verlag Wien, 2014) Kavita Shah; Saumya Gupta; Hirdyesh Mishra; Prashant K. Sharma; Amit Jayaswal
Acquired immunodeficiency syndrome (AIDS) is a major health problem in many parts of the world. The human immunodeficiency virus-1 integrase (HIV-1 IN) enzyme has been targeted in HIV patients for therapy. Several integrase inhibitors have been reported, but only elvitegravir (EVG), a new-generation drug, is clinically approved for HIV treatment. In the present work, we investigated two structural analogs of EVG as potential inhibitors of the target molecule, HIV-1 IN. The ligand binding site on HIV-1 IN was identified using Q-SiteFinder, and the HIV-1 IN protein was docked with ligand (EVG and/or analogs) using AutoDock 4. The results suggest that Lys173, Thr125, and His171 are involved in enzyme-substrate binding through hydrogen bonds. Single mutations carried out at Lys173, viz. Lys173Leu (polar > nonpolar) and Lys173Gln (polar > polar), in chain B using PyMOL showed the mutants to have lower binding energy when docked with analog 2, suggesting it to be more stable than analog 1. In conclusion, the mutant HIV-1 IN can bind EVG and its analogs. The physicochemical and pharmacokinetic parameters also show analog 2 to be a promising molecule that can be developed as an alternative to EVG to help overcome the problem of drug resistance by HIV to this inhibitor. Analog 2 may be used as an HIV-1 IN inhibitor with similar potential to that of EVG. Further validation through wet-lab studies, however, is required for future applications. © 2014 Springer-Verlag Wien.
Examining the uptake and bioaccumulation of molybdenum nanoparticles and their effect on antioxidant activities in growing rice seedlings
(Springer Science and Business Media Deutschland GmbH, 2021) Prashant K. Sharma; Akhilesh S. Raghubanshi; Kavita Shah
The synthesized α-MoO3 and MoS2 NPs had nanosheet and nanoflower-like structures with crystallite size of 21.34 nm and 4.32 nm, respectively. The uptake, bioaccumulation, and impact of these two Mo-NPs were studied in rice (Oryza sativa L) cv. HUR 3022 seedlings exposed to 100, 500, and 1000 ppm concentrations in hydroponics for 10 days in the growth medium. The uptake of α-MoO3 and MoS2 NPs by rice exposed to 100 ppm concentrations of NPs led to the accumulation of 7.32 ppm/4.55 ppm and 1.84 ppm/1.19 ppm in roots/shoots, respectively, as compared to controls. Unlike MoO3, more accumulation of MoS2 in roots reflect less translocation of this NP from roots to shoots. Results suggest tissue-specific distribution of NPs in rice seedlings. The increased growth and elevated protein levels in rice seedlings at 100 ppm concentrations of nanoparticles imply a stimulation in the repair mechanism at low doses indicating hormesis. MoS2 NPs treatments led to increased chlorophyll a levels suggesting it to be non-compromising with photosynthetic process in rice. The high malondialdehyde levels and altered activities of antioxidant enzymes GPX, APX, and CAT in rice seedlings exposed to α-MoO3 or MoS2 NPs indicate oxidative imbalance. Between α-MoO3 and MoS2 NPs, the former shows toxic effects as reflected from the decreased levels of photosynthetic pigments at all concentrations; however, an activation of chloroplast ROS detoxification is evident in the presence of MoS2 NPs. The BCF > 1 for both α-MoO3 and MoS2 NPs and TF of 0.6–2.0 and 0.42–0.65 suggest the latter to be more environmentally safe. In conclusion, a100 ppm MoS2 NPs concentration has low translocation and less accumulation with no significant impact on growth of rice cv. HUR 3022 seedlings and appears to be environmentally safe for future applications. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.