Indian Journal of Chemistry (IJC)

Process Optimization and Kinetic Evaluation of Amberlite IR 120 and Sulphamic acid Catalyzed Esterification of Acetic acid and Methanol

2023-12-21T09:59:56+0530

The Box-Behnken design-based Response Surface Methodology (RSM) has been effectively utilized to optimize the parameters for operation in the amberlite IR 120 and sulphamic acid-catalyzed esterification of methanol and acetic acid. The impact of three process variables, temperature, catalyst loading, and the mole ratio of methanol to acetic acid on esterification was evaluated. The esterification process exhibited excellent concordance between the predicted values and the experimental values (R² = 98.33 % and Adj-R² = 92.08 %), which indicated the suitability of the Box-Behnken model employed. The interaction of the parameters is also studied based on its P-value with the help of ANOVA variance. The second-order kinetic rate equation is applied to correlate the experimental data. By employing the Arrhenius graph, the rate constants for the backward (12.727 × 10⁸ lit mol^-1 min^-1) and forward reactions (2.324 × 10⁴lit mol^-1 min^-1), as well as the energy of activation using amberlite IR 120, were determined. The statistical methodologies, including factorial design and Box-Behnken response, have been employed to model the conversion of acetic acid using various regression techniques for a quadratic equation. The result shows that the amberlite IR 120 catalyst was better than the sulphamic acid catalyst due to the more active catalyst surface area.

Synthesis, Spectral Analysis and Anti Cancer Activity of of (E)-2-(4-((1-phenyl-1H-1,2,3-triazol-4-yl)methoxy)phenyl)-1-(benzo[d]thiazol-2-yl)diazene

2024-07-25T17:17:54+0530

The present work provides a comprehensive guide to the design and high-yield synthesis of 1,2,3-triazole derivatives employing a wide range of chemicals, bases, and catalysts. It is simple, efficient, and effective to develop this methodology We have developed amide coupling reagents that are more convenient, milder, and allow for higher selectivity under mild reaction conditions. benzo[d]thiazol-2-amine (I) treated with NaNO₂/HCl gives diazonium salt (II) and compound (II) reacts with Phenol gives intermediate (III). To get phenoxide compound (IV) compound (III) is treated with K₂CO₃/DMF. To get (E)-1-(benzo[d]thiazol-2-yl)-2-(4-(prop-2-ynyloxy)phenyl)diazene (V), compound (IV) is treated with 3-bromoprop-1-yne. Derivatives of (VIa-p) is synthesized when compound (V) is treated with Aniline and CuI/THF. The derivatives of (VIa-p) has showed moderate to excellent efficacy when tested for anticancer properties against several cancer cell lines. The MCF-7 cell line was the most resistant to compounds 6a and 6e, with an IC₅₀ value of 1.92 and 1.99µM respectively. In order to determine the structures of the newly synthesized compounds, ¹H NMR, ¹³C NMR, IR, and ESI-HRMS were used.

COX-2 as a Therapeutic Target: A Computational Approach to Indole Alkaloids for Analgesic Design

2024-03-01T17:08:57+0530

Medicinal plants provide natural compounds that aid in biological processes, including the treatment of inflammation-related disorders. These have been connected to a direct inhibitory binding mechanism, particularly on the COX-2 protein. The present work describes an in-silico analysis of chosen alkaloids for COX-2. The goal is to analyze the structural and conformational characteristics of these selected indole alkaloids to determine its inhibitory properties and demonstrate its binding manner in the COX-2 active site. The compounds exhibit distinct interactions, involving both hydrogen bonding and van der Waals forces, with specific amino acid residues within the COX-2 binding site. Trigonoliimine C forms hydrogen bonds with Met 522 and Val 523, accompanied by van der Waals interactions with key residues such as Val 116 and Trp 387. Trigonoliimine A demonstrates hydrogen bonding with Tyr 355 and van der Waals interactions with Pro 84 and Phe 518. Flinderole C engages in hydrogen bonding with Phe 381 and Ser 353, coupled with van der Waals interactions with Val 89 and Tyr 385. Ramiflorine B exhibits hydrogen bonding with Tyr 355 and van der Waals interactions with Thr 85 and Ser 530. Ramiflorine A, forming hydrogen bonds with Tyr 355 and engaging in van der Waals interactions with Pro 84 and Phe 518, showcases a remarkable specificity in molecular recognition. These findings provide valuable insights into the potential therapeutic applications of these compounds, offering a foundation for further experimental validations and the development of novel anti-inflammatory agents targeting COX-2.

Synthesisandphotoluminescent properties of Eu3+, Dy3+doped molybdate based novel Ba0.5Ca0.5La2(MoO4)4 phosphors

2024-01-24T05:21:32+0530

Ba_0.5Ca_0.5La_2-x-y(MoO₄)₄:xEu³⁺,yDy³⁺ with doping concentrations of xEu³⁺ and yDy³⁺ (x =0.01, 0.03, 0.05, 0.1 and y= 0.01) phosphors were synthesized by solid state reaction method, one of the high temperature solid state methods. The reactions were carried out in an tube furnace at determined temperatures. Thermogravimetry-differential thermal analysis (TG/DTA) system was used to determine the synthesis temperature of the material and to examine its thermal behavior . The crystal structure of the material was checked with x-ray powder diffractometry (XRD), surface morphology and elemental analysis were done with scanning electron microscope (SEM). The photoluminescent properties of luminescence and excitation wavelength and luminescence duration were determined by photoluminescence spectrophotometer (PL). As a result of the analyzes made with photoluminescence spectrophotometer, three emission bands were observed at 619 nm, 652 nm and 706 nm, resulting from the characteristic ⁵D₀→⁷Fj (J=2, 3 and 4) transitions of Eu³+ ions.

Flower-like NiCo2S4/rGO composites directly grown on Ni Foam as highly efficient electrode for long cycling stability supercapacitor

2024-05-24T16:32:59+0530

NiCo₂S₄ and reduced graphene oxide(rGO) were directly grown on Ni foam by a two-step hydrothermal method to form NiCo₂S₄/rGO composite material with hierarchical structures. The resulting samples displayed flower-like NiCo₂S₄particles formed by interconnected NiCo₂S₄ nanosheets with the conductive rGO sheets interspersing among them. This unique structure can provide a much rougher surface, rich two-phase interface, and porous channels exposed to electrolytes with fast ion diffusions and electron transmissions, as well as effectively relieve the expansion/contractions during charging and discharging. The electrochemical test results show that NiCo₂S₄/rGO composite prepared at 120 ℃ with 8.1 mg mass loading on Ni foam exhibits a specific capacitance (1974.7 F·g^-¹) at a current density of 10 mA·cm^-². An asymmetric supercapacitor device assembled by NiCo₂S₄/rGO and activated carbon can provide an energy density high up to 46.8 Wh·kg^-1 at a power density of 219.5 W·kg^-1. Even if the power density is increased up to 731.6 W kg^-1, it still can achieve the energy density superior to 31.8 Wh kg^-1. Moreover, the asymmetric supercapacitor device exhibits an outstanding cycling stability with 87.8% capacitance retention after 5000 cycles, which confirms its potential application in the energy storage.

Understanding the Effect of Carbon Dots with Size Variation on Collagen

2024-02-13T14:04:26+0530

The unique optical properties of carbon dots (CDs) offer a wide variety of applications both in chemical and biological environments. The interaction of CDs with biological molecules such as proteins and DNA has been studied extensively. In the present study, the interaction of two different sizes of CDs with collagen, a fibrillar protein, has been investigated. The different sizes of CDs have been characterized using various techniques such as HR-TEM, SEM, and zeta potential. Upon interaction with CDs, the triple helical nature was not altered and R_pnvalue was similar to the control collagen. The influence of size on the fibrillation of collagen process was significantly impacted with photoirradiation process. Similarly, in DSC experiments, the CDs destabilized the collagen with DTm value of 16±1°C but with photoirradiation, the stability of the collagen was improved but less than the control collagen. In EPR studies upon photoirradiation, a significant amount of generation of hydroxyl radical was observed. The gel electrophoresis studies show that the presence of CDs did not inhibit the collagenase activity without or with photoirradiation. The data from the present study clearly reveals that the understanding the biocompatibility of carbon dots for bioengineering applications.

Heat dissipating multi-component inorganic mixture of iron with high-temperature dielectric behavior

2024-04-02T12:30:08+0530

Synthesis and characterization of two multicomponent mixtures, 0.8 Fe₃(PO₄)₂. 4H₂O . 0.8 FePO₄. 2H₂O . 0.5 NH₄H₂PO₄. 0.2(NH₄)₂SO₄ (FPN2A) and 0.8 Fe₃(PO₄)₂ .8H₂O. 0.8FePO₄. 0.5NH₄H₂PO₄. 0.2(NH₄)₂SO₄ (FPN2B) are reported. FPN2A and FPN2B mixtures have average crystallite sizes of 66.1 nm and 79.5 nm, respectively. The respective optical bandgap of FPN2A and FPN2B are 6.02 eV and 5.96 eV with a refractive index of 1.99. Thermal analysis revealed heat-dissipating behaviour of the mixtures with specific heat capacity, C_P (at 307 K) of 0.71 Jg^-1K^-1 and 0.66 Jg^-1K^-1 for FPN2A and FPN2B, respectively. Further, temperature-frequency dependant dielectric properties of the FPN2C (obtained by sintering FPN2B at 423 K) have been investigated. The sintered mixture, FPN2C orchestrated variation in permittivity, (∼ 17 – 42) and dielectric loss, (∼ 0.04-0.08) in the frequency range of 1.0×10³ Hz to 4.0×10⁶Hz up to 483 K. AC conductivity of FPN2C was found to be ∼ 8.96 ´ 10^-⁸ sm^-1up to 483 K. TG-DSC analysis revealed the thermal stability of the FPN2C over a wide range of temperature (297 K to 1267 K) and heat-dissipating behaviour with a C_Pof 0.62 Jg^-1K^-1.

The Synthesis, Characterization and Antimicrobial Evaluation of Triazole Substituted Pyrimidine Derivatives

2024-04-04T22:28:21+0530

The present investigation was conducted with the purpose of creating a novel class of 1,2,3-triazole linked Pyrimidine hybrids using Cu(I)-catalyzed azide-alkyne cycloaddition (NaAAC) with high yields (80-90%) by utilizing different poly-halogenated compounds that have been synthesized. The structures of the newly synthesized compounds were determined using ¹H NMR, ¹³CNMR, IR, and ESI-HRMS. All compounds exhibiting pharmacological evidence of antimicrobial action are provided. The efficacy of synthetic compounds in eradicating bacteria and fungus was examined and compared to that of established antibiotics such as ciprofloxacin and ketoconazol, respectively. Among all the compounds, compounds 4a&f exhibited the highest levels of activity. The compounds were tested for their properties against Bacillus subtilis, Escherichia coli, and Aspergillus flavus, Candida albicans.

SYNTHESIS, CHARACTERIZATION, MOLECULAR DOCKING, ADMET PROPERTIES AND IN-VITRO ANTI-INFLAMMATORY SCREENING OF SOME ISOXAZOLINE DERIVATIVES

2024-04-09T15:43:35+0530

This paper describes the synthesis of isoxazoline derivatives using Bi₂O₃-TiO₂nanocatalyst. The (E)-3-(2-amino-3,5-dibromophenyl)-1-(substituedphenyl)prop-2-en-1-one were treated with hydroxylamine hydrochloride in the presence of nanocatalyst Bi₂O₃-TiO₂and ethanol as solvent to yield 2,4-dibromo-6-(3-(substitutedphenyl)-4,5-dihydroisoxazol-5-yl)aniline (8-14). The final product separated and purified by ethanol recrystallization. The obtained final product (8-14) was characterized by elemental analysis, FT-IR, ¹HNMR and ¹³CNMR spectral studies. Synthetic transformation details, smallest catalytic amounts, excellent product yields, and suitable solvent for the formation of these isoxazoline scaffolds are elucidated. Synthesized derivatives screened for their in-vitro anti-inflammatory activity using HRBC method. The obtained in vitro results were compared with the molecular docking with protein, DNA Gyrase (PDB ID: 3U2D), Cyclooxygenase-1 (PDB ID: 3N8V) and Cyclooxygenase-2 (PDB ID: 3LN1) enzyme using Schrodinger suit Maestro 11.2 version. Insilico ADMET screening also performed by qikprop module of Schrodinger suit.

Nickel-Catalyzed Mizoroki–Heck Cross-Coupling Reaction of Aryl halides with Styrenes

2024-04-19T02:38:35+0530

Presenting here an efficient and a simple protocol using 10 mol % of NiCl₂.6H₂O, 20 mol % of 2, 3-dihydroxy naphthalene, 50 mol % of CTAB, and 2 equiv. of NaOH in 2.5 mL of DMF at 150 °C for C-C bond forming Mizoroki-Heck coupling. Use of styrene and 4-methyl styrene with various aryl iodides and bromides having functionalities such as methyl, methoxy, nitro, fluoro, chloro, hydroxyl, trifluoromethyl, Methyl, and methoxy aryl halide showed smooth conversion with 50 to 93 % isolated yield. The electron-withdrawing groups like nitro at para-position gave a lower yield. The aryl iodides were found to be more reactive than aryl bromides. The advantages of this protocol are moderate to excellent yield in the absence of an inert atmosphere, and the use of cheap and readily available catalyst.

Additions and Corrections

2024-08-21T17:09:43+0530