Showing papers by "Chhagan Lal published in 2022"

Modified 7-Chloro-11H-Indeno[1,2-b]Quinoxaline Heterocyclic System for Biological Activities

Abstract: Recent advances in functionalized organic Spiro heterocyclic compounds composed of nitrogen bonded five- and six-membered rings have been made, establishing them as a synthetic target in organic-based biomedical applications. In this work, we report a synthesis of spirocyclic compounds under a one-pot reaction using 1,3-dipolar cycloaddition in a regio and diastereoselective manner. The higher atomic economy with higher yield (95%) and regio and stereoselectivity were achieved by a multi-component reaction of L-proline (1), Indenoquinoxaline (2), and the dipolarophile of malononitrile (3) solvents followed by reflux conditions. The reaction intermediate comprised azomethineylides derived from reactive primary amines, and the spiro derivatives were synthesized up to a ≈ 95% yield. The structural and characteristic chemical components of the as-prepared Spiro compounds were characterized by 1H-NMR, FTIR, and Mass spectroscopy. The functionalized spiro-pyrrolizidines were found to be effective for biological uses by considering their in vitro screening and antimicrobial impacts. Spiro constituents were found to be much more effective for Gram-positive bacteria due to the stronger lipophilic character of the molecules, and they resulted feasible membrane permeation in a biological system. Based on the planarity geometry of the Spiro pyrrolizidines, meta-substitution possesses steric hindrance and hence shows less effectiveness compared to para-substitution on the same nucleus, which shows a marginal steric effect. The biological studies showed that the derived spiro heterocyclic systems have an inhibitory effect of 50%.

Spectroscopic Investigations of Optical Bandgap and Search for Reaction Mechanism Chemistry Due to γ-Rays Irradiated PMMA Polymer

Abstract: Radiation damage and the product formation chemistry in Polymethyl methacrylate (PMMA) due to γ-irradiation have been studied by SEM, XRD, FTIR, and UV-Vis spectroscopy. Co-60 gamma source with a dose rate of 1.707 kGy/hr has been used for irradiation to a total 570 kGy dose. No significant changes in morphology upon such irradiation. Crystallinity decreases at a lower dose and then increases for a higher dose. Crosslinking dominates at lower doses, and chain scission overwhelms at higher doses in the irradiated polymer. Two isosbestic points are formed, and the absorption maxima shift towards a higher wavelength. The optical bandgap energy decreases with the addition of radiation dose. A new FTIR peak at 1638 cm-1 appeared, suggesting the formation of an unsaturation center in the irradiated polymer. Up to a dose of 409 kGy, FTIR absorption peak intensity increases and decreases with further irradiation.

Enhanced Plasmon Based Ag and Au Nanosystems and Their Improved Biomedical Impacts

Abstract: Numerous specialists and academics have backed the improved physicochemical characteristics of metal substrate (Ag, Au) based composite nanoparticles for a number of applications, including pharmaceuticals, optoelectronics, and environmental impact. Insights of Ag and Au NPs-based nanomaterials will be discussed, as well as important production, physicochemical, and biotechnological characteristics. The plasmon capacities of Ag and Au NPs, along with their customisable form, scale, and surface modification could be described by specified geometries and constituent contents. It was revealed that interaction dynamics of Ag and Au implanted nanomaterials with dopants/defects ratios seem to be more effective in stimulating pathogens by interrupting biochemical reactions. As a result, we focus on defect science in Ag and Au-based nanoscale materials, taking into account surface morphology, ionic packing, and chemical phase assessment. This chapter will cover the important optical, geometrical, and physicochemical features of Ag and Au nanomaterials, and their pharmacological significance.

Synthesis and Characterization of Silver Nanoparticles by Murraya Koenigii Leaves

Abstract: Nanoparticles have a size of 1nm-100nm in any one of the three dimensions. Smaller nanoparticles have different physical, chemical and biological properties than atoms and molecules. Metals, non-oxide ceramic materials, metal oxides, silicates, and polymers, and organic and biomolecular components can be used to create material nanoparticles. Nanoparticles come in various shapes, like spheres, platelets, cylinders, and tubes. Green synthesized nanoparticles are not costly due to unemployment of toxic and hazardous compounds. Plants are widely spread, freely accessible, and safe to touch. They also supply a variety of metabolic compounds which are advantageous in reducing, capping and stabilizing process throughout in synthesis process. The reduction mechanism is based on the phytochemicals present in plant extract. In present work we synthesize silver nanoparticles by using Murraya Koenigii leaves through ecofriendly method. For synthesis of Silver nanoparticles, Silver nitrate (AgNO3) used as metal precursor salt and green extract of Murraya Koenigii used as reducing and capping agent for formation of nanoparticles. The nanoparticles then formed characterized by X-ray diffraction, Scanning electron microscope, Energy dispersive spectroscopy, Dynamic light scattering, Fourier transform infrared spectroscopy and optical properties by UV-Visible spectroscopy. XRD revealed the crystalline structure of silver nanoparticles, FESEM and Dynamic light scattering reveled the particle size of 60 nm, FTIR revealed the presence of different functional groups which are attached with sample and Optical properties of sample revealed by UV-Visible spectroscopy that also satisies different experimental results.

Degradation of dyes using biologically synthesized iron oxide nanoparticles by manilkara zapota leaves extract

Abstract: In this work, we obtained iron nanoparticles from the aqueous extract of the leaves of M. zapota and protected the environment by decreasing toxic chemicals and eliminating biological risks in biomedical applications. Different concentrations of leaf extract(0.25 g/mL, 0.125 g/mL, 0.0625 g/mL, and 0.0312 g/mL)were used and synthesized iron oxide nanoparticles. The results revealed a dependence on the particle size of Fe2O3 NP and synthesis conditions. The Fe2O3 NP samples UV–visible absorption spectra show surface plasmon (SPR) bands around 355 nm, 344 nm, 346 nm, and 344 nm at different extract concentrations. Different structural, elemental, and optical properties were analyzed by various techniques such as XRD, SEM-EDX, and FTIR. The photocatalytic activity of the produced iron nanoparticles was evaluated for the degradation of Methylene blue dye under solar irradiation. At 8 hours of exposure, green-produced iron nanoparticles efficiently destroyed the dye by almost 53.57 percent.

Biosynthesis of Nanoparticles using Microorganisms and their Applications

Abstract: Materials behave in a different way when they are in their nano sizes. Nanomaterials encompass a high surface-to-volume ratio, a high adsorption capacity, high sensitivity, and reactivity, hence these can be efficiently used for textile wastewater treatment. Numerous studies have shown that nanoparticles can effectively eliminate various pollutants of domestic and industrial effluent. Nanoparticles are conventionally synthesized by physical and chemical methods but these methods use toxic chemicals, complicated procedures, and expensive materials. Presently, enzymatic processes are the most preferred method as they are economically cheap and environmentally sustainable. Microorganisms, break down the metal salts into metal nanoparticles, which can be isolated and used for textile dye degradation. This review epitomizes the various biosynthesized metal and metal oxide nanoparticles by different microorganisms and if they are efficient to degrade diverse textile dyes.

Modification of Optical Bandgap and Formation of Carbonaceous Clusters Due to 1.75 MeV N5+ Ion Irradiation in PET Polymers and Search for Chemical Reaction Mechanisms

Abstract: The effects of 1.75 MeV N5+ ion beams of varying fluences, ranging from 1x1011 to 5x1014 ions/cm2 on structural, optical, and chemical properties of polyethylene terephthalate (PET) polymer, have been investigated by x-ray diffraction (XRD), UV–Visible spectroscopy, and Fourier transform infrared (FTIR) spectroscopy. The XRD patterns of PET samples show that the crystallinity increases with ion irradiation of fluences 4x1011 and 5x1012 ions/cm2. Optical bandgap energy decreases more at the ion fluences of 5x1014 ions/cm2. Absorption maxima shifted towards a higher wavelength value due to the formation of extended conjugation. Acetylenic (-C≡C-) group formation and free CO2 group are confirmed by FTIR spectroscopy. The reaction mechanism of the degradation product formation chemistry is discussed.