Browsing by Author "Nikita Gupta"

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Improvised strategy of ethanolic nanovesicular gel of phospholipon 90G for transdermal delivery of luliconazole to mitigate fungal diseases
(Springer Science and Business Media Deutschland GmbH, 2023) Vivek Dave; Nikita Gupta; Anand Prakesh; Prashansa Sharma
The research work involves the development and characterization of ethanolic nanovesicular gel of different concentrations of the specified chemicals so as to estimate the optimized one among the rest. For the determination of its stability and suitability, optimized formulation was carried to a number of evaluation parameters such as particle size, zeta potential, polydispersity index (PDI), % entrapment efficiency (%EE), attenuated total internal reflection Fourier transforms infra-red spectroscopy (ATR-FTIR), transmission electron microscopy (TEM), atomic force microscopy (AFM), in vitro drug permeation study, stability studies, viscosity, pH, spreadability, extrudability, and last but not least, anti-fungal activity done by considering tube dilution assay. And finally, the results obtained were recorded and analyzed for all the parameters. The outcomes revealed that among nine nanovesicular formulations, ENV5 was found to be optimized, as because of its appropriate results for particle size, PDI, and zeta potential and highest % entrapment efficiency of about 169.5 nm, 0.407, −37.9 mV, and 80.07 ± 0.55% respectively, whereas in vitro drug permeation study expresses % cumulative release of 78.59 ± 0.43 in about 24 h. The suspension of nanovesicular system and lyophilized form of nanovesicular suspension both were examined and found to be very much stable at 4°C/60 ± 5 % RH than that of 25 °C/60 ± 5 % RH. Ultimately, the outcomes of the evaluation parameters have proved that the buildup is stable and suitable for topical application hence, leading to efficacious therapy of fungal diseases. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
Lighting the Path: A Sustainable Catalyst Free Approach Toward Trifluoromethylation of Indoles
(John Wiley and Sons Inc, 2025) Nikita Gupta; Imtiaz Ahmed; Ajit Kumar Gupta; Kalpajyoti Dihingia; Biswajit Maiti; Vijay Kumar Das
In this study, we report an innovative development of a visible light-induced synthesis of trifluoromethyl indoles. This novel methodology not only obviates the need for traditional catalysts but also harnesses the energy of photons to selectively introduce trifluoromethyl groups into indole substrates. Leveraging the inexpensive, easily handled, and non-toxic Langlois reagent (CF3SO2Na) as the CF3 source, in conjunction with visible light and tert-butyl hydrogen peroxide (TBHP), facilitates the direct C─H trifluoromethylation of indoles. The mechanistic pathway of the reaction is predicted with the help of density functional theory (DFT) calculations at the (U)B3LYP/6–31++G(d,p)/SMD/acetonitrile level of theory. © 2025 Wiley-VCH GmbH.
Nanohybrids: A Burgeoning Need to Cater C−C and C−O Bonds Building in Organic Synthesis
(John Wiley and Sons Inc, 2023) Nikita Gupta; Kumar Anku; Anurag Singh; Sampurna Routray; Ankita Kar; Vijay Kumar Das
Nanohybrids (NHs) based on the conjugation of multiple carbonaceous nanomaterials and metal/metal oxides, are emerging as important photocatalysts of 21st century and have tremendous future scopes. Overcoating one material on top of another in NHs improves performance and multifunctionality growth for a wide range of catalytic applications in organic transformations. The catalytic activity of NHs brings a phenomenal change towards various organic synthetic reactions to improve their selectivity, productivity and yield. Thus, with the background of this context, the current review covers the state of art literature up to July 2022 and brings a comprehensive discussion on the entitled subject matter. As emphasized in this review, the application of heterogeneous NHs for common organic reactions has been confirmed to be a successful tactic for the growth of extremely resourceful conversions in terms of atom economy, atom efficiency E-factor and selectivity. It also highlights the extensive and critical aspects to explore the catalytic prospects and challenges of NHs from obscurity to eminence. © 2023 Wiley-VCH GmbH.
Photochemically Induced Approaches to the Syntheses of β-Lactams
(John Wiley and Sons Inc, 2024) Imtiaz Ahmed; Nikita Gupta; Ajit Kumar Gupta; Vijay Kumar Das
The synthesis of β-lactam scaffolds is of paramount importance due to their extensive applications in pharmaceuticals, particularly as antibiotics. Visible light photocatalysis has emerged as a revolutionary approach in this domain, providing a sustainable and efficient pathway for β-lactam construction. In this review, we meticulously discuss the recent developments in the synthesis of photocatalysed β-lactam frameworks. A key focus is the Staudinger reaction, traditionally a cornerstone in β-lactam synthesis, and its adaptation to visible light photocatalysis. We explore the mechanistic intricacies of the Staudinger reaction under photochemical conditions, along with other pivotal cyclization strategies enabled by visible light. By illuminating the novel photocatalytic routes to β-lactams, this review provides a thorough understanding of the state-of-the-art techniques and sets the stage for future innovations in the green synthesis of these critical compounds. © 2024 Wiley-VCH GmbH.
Photoemission and optical constant measurements of a cesium iodide thin film photocathode
(Elsevier, 2015) Triloki; R. Rai; Nikita Gupta; Nabeel F.A. Jammal; B.K. Singh
Abstract The performance of cesium iodide as a reflective photocathode is presented. The absolute quantum efficiency of a 500 nm thick film of cesium iodide has been measured in the wavelength range 150 nm-200 nm. The optical absorbance has been analyzed in the wavelength range 190 nm-900 nm and the optical band gap energy has been calculated. The dispersion properties were determined from the refractive index using an envelope plot of the transmittance data. The morphological and elemental film composition have been investigated by atomic force microscopy and X-ray photo-electron spectroscopy techniques. © 2014 Elsevier B.V. All rights reserved.
Visible light-driven modular synthesis of aza-β-lactams via a dual photochemical cascade
(Royal Society of Chemistry, 2025) Imtiaz Ahmed; Nikita Gupta; Plaban Jyoti Sarma; Shilpa Neog; Vijay Kumar Das
The development of efficient and sustainable synthetic routes to nitrogen-containing heterocycles remains a cornerstone of modern organic chemistry. Herein, we report a visible-light-induced [2 + 2] cycloaddition reaction between photogenerated ketenes and azoarenes, providing a mild and high-yielding route to aza-β-lactams—versatile scaffolds with significant pharmaceutical and synthetic relevance. The ketene intermediates are generated in situ from N-tosylhydrazones under mild, transition metal-free conditions, leveraging visible light as a renewable energy source. This strategy delivers excellent yields (up to 99%) and exhibits broad substrate scope (22 examples), accommodating diverse electronic and steric variations. Notably, mechanistic insights, supported by experimental studies and density functional theory (DFT) calculations, reveal a stepwise pathway involving ketene formation followed by cyclization. This study expands the synthetic utility of photogenerated ketenes and further establishes a versatile platform for the controlled assembly of nitrogen-containing heterocycles under visible-light activation. The EcoScale evaluation of our optimized protocol yielded a score of 86.5, indicating an excellent level of sustainability based on reagent safety, energy input, and workup efficiency. © 2025 The Royal Society of Chemistry.