Showing papers on "Thioglycolic acid published in 2023"

Microwave-assisted synthesis, antioxidant activity, docking simulation, and DFT analysis of different heterocyclic compounds

Abstract: In this investigation, pressure microwave irradiation was used to clarify the activity of 1-(2-hydroxyphenyl)-3-(4-methylphenyl)prop-2-en-1-one (3) towards several active methylene derivatives utilized the pressurized microwave irradiation as green energy resource . Chalcone 3 was allowed to react with ethyl cyanoacetate, acetylacetone, and thioglycolic acid; respectively, at 70 °C with pressure under microwave reaction condition to afford the corresponding 2-hydroxyphenylcyanopyridone, 2-hydroxyphenyl acetylcyclohexanone, and thieno[2,3-c]chromen-4-one derivatives respectively. Moreover, the reaction of chalcone 3 with hydrogen peroxide with stirring affords the corresponding chromen-4-one derivative. All the synthesized compounds were confirmed through spectral tools such as FT-IR, 1HNMR, 13CNMR, and mass spectrum. Furthermore, the synthesized heterocycles were exhibited excellent antioxidant activity and comparable with vitamin C, where the presence of the OH group increases the scavenger radical inhibition. Furthermore, the biological activity of compound 12 was demonstrated through molecular docking stimulation using two proteins, PDBID: 1DH2 and PDBID: 3RP8, which showed that compound 12 possesses greater binding energy and a shorter bond length comparable with ascorbic acid. Also, the compounds were optimized through DFT/B3LYP/6-31G (d,p) basis set and identification of their physical descriptors, whereas the compound 12 was confirmed through X-Ray single structure with Hirsh field analysis of the compound to know the hydrogen electrostatic bond interaction, and correlated with the optimized structure by comparing their bond length, bond angle, FT-IR, and NMR, which gave excellent correlation.

Premicellar effects on the reduction of N, N′-phenylenebis(salicylideneiminato)iron(III) by thioglycolic acid: Kinetic study and mechanism

Abstract: The reduction kinetics of N,N′-phenylenebis(salicylideneiminato)iron(III), [Fe(salphen)]+ by thioglycolic acid (TSH) has been carried out in mixed aqueous medium (DMSO:H2O; 1:4) in pseudo-first order condition at 26 ± 1 °C. A CORNING colorimeter 253 was used to monitor the reaction rates by detecting the absorbance reduction of the reaction at 435 nm. The reaction was acid independent, second order overall and demonstrated zero Brønsted-Debye salt effect. Ions such as Mg2+ and CH3COO- catalyzed the reaction. The thermodynamic parameters indicated an activated complex that is much ordered and a highly solvated transition state. Reaction catalysis was observed in the case of sodium dodecylsulphate (SDS) and cetyltrimethylammonium bromide (CTAB) inclusion. The critical micelle concentrations obtained for SDS were 8.0 × 10−3 and 3.3 × 10−3 mol dm−3 whereas that observed for CTAB were 2.0 × 10−3 and 2.8 × 10−3 mol dm−3 in water and [Fe(salphen)]+ reaction media respectively. Piszkiewicz model was used to analyze the results which indicated the existence of pre-micellar aggregates and significant electrostatic and hydrophobic interactions between the metal complex and the pre-micellar aggregates of the surfactants. The cooperativity index and binding constants obtained were n = 1.22, K = 4.78 × 104 dm3 mol−1, n = 1.27 and K = 4.55 × 104 dm3 mol−1 respectively for SDS and CTAB. A plausible mechanism suggesting an outer-sphere mechanism has been postulated.

Synthesis of Thiolated Cashew Gum and Its Evaluation as an Improved Mucoadhesive Agent in Drug Delivery

Abstract: The objectives of present research work were to extract cashew exudate gum (CG), perform thiolation of extracted CG, and evaluate the synthesized thiolated cashew exudate gum (TCG) as a mucoadhesive agent in designing metronidazole mucoadhesive gels and metronidazole mucoadhesive buccal discs. The CG was thiolated or thiol-modifi ed via esterifi cation utilizing thioglycolic acid and hydrochloric acid. Metronidazole mucoadhesive gels and metronidazole mucoadhesive buccal discs made of unmodifi ed CG and TCG (as mucoadhesive agent) were formulated and evaluated to reveal their bio-mucoadhesive potentials in drug delivery. The yield of thiolated product (TCG) was 56.24%, and the thiol-group content in TCG was found to be 9.06 mM of thiol group/g of CG. FTIR analysis indicated the thiolation of CG in the synthesized TCG. Both types of formulations (mucoadhesive gels and buccal discs) made of TCG exhibited excellent improved ex-vivo bio-mucoadhesion and consistent pattern of metronidazole releasing over a prolonged time. The synthesized TCG can be utilized as an improved mucoadhesive material in designing bio-mucoadhesive systems for drug delivery.

Core and Shell Contributions to the Phonon Spectra of CdTe/CdS Quantum Dots

Abstract: The parameters of the shell and interface in semiconductor core/shell nanocrystals (NCs) are determinant for their optical properties and charge transfer but are challenging to be studied. Raman spectroscopy was shown earlier to be a suitable informative probe of the core/shell structure. Here, we report the results of a spectroscopic study of CdTe NCs synthesized by a facile route in water, using thioglycolic acid (TGA) as a stabilizer. Both core-level X-ray photoelectron (XPS) and vibrational (Raman and infrared) spectra show that using thiol during the synthesis results in the formation of a CdS shell around the CdTe core NCs. Even though the spectral positions of the optical absorption and photoluminescence bands of such NCs are determined by the CdTe core, the far-infrared absorption and resonant Raman scattering spectra are dominated by the vibrations related with the shell. The physical mechanism of the observed effect is discussed and opposed to the results reported before for thiol-free CdTe Ns as well as CdSe/CdS and CdSe/ZnS core/shell NC systems, where the core phonons were clearly detected under similar experimental conditions.

Synthesis, Antimicrobial Activity, and Drug-likeness profiles of 5-Phenylselenanyl-2-benzylthiopyrimidine Analogs

Abstract: Abstract Given literature findings on the biological importance of pyrimidine and thiazolidine, we herein report synthesis and antimicrobial activity of 5-phenylselenanyl-2-benzylthio- pyrimidin-4-yl) thiazolidine-4-one analogs 4( a, b ). Compound 5-phenylselenenyl-4-hydrazino-2-benzylthiopyrimidines ( 2 ) on condensation with substituted aromatic aldehydes afforded the corresponding Schiff bases 5-phenylselenenyl-4-(substituted benzylidenehydrazino)-2-benzylthiopyrimidine 3( a-c ). Finally, the cyclization of compounds 3( a-c ) with thioglycolic acid in benzene as solvent yielded target compounds 4( a, b ). The structures of synthesized compounds were characterized by spectral studies such as IR, 1 H-NMR, and Mass spectra. Results obtained by screening these synthesized compounds for antimicrobial activity reveal that only 1, 2, 3a, 3b, and 4a exhibited good antibacterial activity against P. aeruginosa compared to the standard drug gentamycin. Among all pyrimidine analogs, compound 4b has shown good antifungal activity against the fungal strain A. niger and A. terreus . Other compounds have shown moderate to poor antifungal activity when compared with fluconazole. Also, ADMET properties were studied for synthesized compounds.

Biocompatible Nanoarchitectonics of Water‐Soluble Vanadium Dichalcogenides Quantum Dots Functionalized with Capping Agents

Abstract: Herein, three different water-soluble functional groups capped vanadium disulfide quantum dots (VS2QDs), namely, L-cysteine capped VS2QDs (L-cys-VS2QDs), thioglycolic acid capped VS2QDs (TGA-VS2QDs), and 3-mercaptopropionic acid capped VS2QDs (MPA-VS2QDs) are synthesized via hydrothermal method. The comparison of the biocompatibility (MTT assay) of three differently capped VS2QDs is performed in RAW cell 264.7 cells with different concentrations (500, 250, 125, 62.5, 15.625, 7.812, and 3.906 μg mL−1). It is found that L-cys-VS2QDs show more biocompatibility than the TGA-VS2QDs and MPA-VS2QDs. However, at low concentrations, TGA-VS2QDs also show better biocompatibility, whereas MPA-VS2QDs show the least biocompatibility. Biocompatibility of L-cys-VS2QDs is also almost consistent with entire range of QDs concentrations may be due to L-cys cellular inflammation and maintaining pH buffer.

Production of Zn-based quantum dots in the presence of different capping agents

Abstract: Zinc selenide (QDs) has been of great interest in recent decades due to its extraordinary electrical and optical properties, which promote its use as a biomarker, photosensitizer in cancer therapy, and nanocatalyst in cleaning technologies. This research was focused on the synthesis and characterization of thiol-surface modified ZnSe QDs. The presence of an organic cover on the QDs surface can affect its optical properties, such as fluorescence and absorbance. The objectives of this research were: (I) synthesize and characterize water-stable QDs in the presence of 3-mercaptopropionic acid (MPA) and thioglycolic acid (TGA), and (II) study its optical properties. Nanoparticles showed small sizes at ~ 5 nm and cubic zinc blend structures. Emission peaks at 443 nm and 396 nm for quantum dots covered with MPA and TGA were observed. The presence of TGA on the QDs surface enhanced its emission intensity which is attributed to the high passivation of QDs. Graphical abstract

One-Pot Synthesis of 1-Thia-4-azaspiro[4.4/5]alkan-3-ones via Schiff Base: Design, Synthesis, and Apoptotic Antiproliferative Properties of Dual EGFR/BRAFV600E Inhibitors

Abstract: In this investigation, novel 4-((quinolin-4-yl)amino)-thia-azaspiro[4.4/5]alkan-3-ones were synthesized via interactions between 4-(2-cyclodenehydrazinyl)quinolin-2(1H)-one and thioglycolic acid catalyzed by thioglycolic acid. We prepared a new family of spiro-thiazolidinone derivatives in a one-step reaction with excellent yields (67–79%). The various NMR, mass spectra, and elemental analyses verified the structures of all the newly obtained compounds. The antiproliferative effects of 6a–e, 7a, and 7b against four cancer cells were investigated. The most effective antiproliferative compounds were 6b, 6e, and 7b. Compounds 6b and 7b inhibited EGFR with IC50 values of 84 and 78 nM, respectively. Additionally, 6b and 7b were the most effective inhibitors of BRAFV600E (IC50 = 108 and 96 nM, respectively) and cancer cell proliferation (GI50 = 35 and 32 nM against four cancer cell lines, respectively). Finally, the apoptosis assay results revealed that compounds 6b and 7b had dual EGFR/BRAFV600E inhibitory properties and showed promising antiproliferative and apoptotic activity.

Thiol-Surface-Engineered Cellulose Nanocrystals in Favor of Copper Ion Uptake

Abstract: Cellulose, the most abundant natural polymer on earth, has recently gained attention for a large spectrum of applications. At a nanoscale, nanocelluloses (mainly involving cellulose nanocrystals or cellulose nanofibrils) possess many predominant features, such as highly thermal and mechanical stability, renewability, biodegradability and non-toxicity. More importantly, the surface modification of such nanocelluloses can be efficiently obtained based on the native surface hydroxyl groups, acting as metal ions chelators. Taking into account this fact, in the present work, the sequential process involving chemical hydrolysis of cellulose and autocatalytic esterification using thioglycolic acid was performed to obtain thiol-functionalized cellulose nanocrystals. The change in chemical compositions was attributed to thiol-functionalized groups and explored via the degree of substitution using a back titration method, X-ray powder diffraction, Fourier-transform infrared spectroscopy and thermogravimetric analysis. Cellulose nanocrystals were spherical in shape and ca. 50 nm in diameter as observed via transmission electron microscopy. The adsorption behavior of such a nanomaterial toward divalent copper ions from an aqueous solution was also assessed via isotherm and kinetic studies, elucidating a chemisorption mechanism (ion exchange, metal chelation and electrostatic force) and processing its operational parameters. In contrast to an inactive configure of unmodified cellulose, the maximum adsorption capacity of thiol-functionalized cellulose nanocrystals toward divalent copper ions from an aqueous solution was 4.244 mg g−1 at a pH of 5 and at room temperature.

Copper(II) Catalyzed Oxidation of Aliphatic Thiols (Thioglycolic Acid and 2-Mercaptoethanol) by Heteroleptic Co(III)-Bound Superoxo Complex

Abstract: In aqueous acid media (0.02-0.06 M), two aliphatic thiols (RSH) viz. thioglycolic acid (TGA) and mercapto ethanol (MERCAP) were oxidized by heteroleptic metal bound superoxo complex, [(dien)(en)CoIII(O2)CoIII(en)(dien)]5+ (1) (en = ethylenediamine, NH2CH2CH2NH2 and dien = diethylenetriamime, NH2(CH2)2NH(CH2)2NH2) to the corresponding disulphides. Complex 1 is reduced to its corresponding peroxo complex, [(dien)(en)CoIII(O2)CoIII(en)(dien)]4+ (2) in these reactions. The oxidation of both thiols were dramatically catalyzed by the presence of Cu2+ ion. The observed rate constant ko was found to be proportional to [RSH]2 and [Cu]T 2 (where [Cu]T is the analytical concentration of Cu2+). The rate of reaction decreases with increasing ionic strength (I) of the reaction media and ko is also proportional to [H+]2–. The experimental observation suggests that a 1:2 anionic complex formed between Cu2+ and RSH participates in the redox cycle.

Effect of Functionalized CdSSe Quantum Dots in the CYP450 Activity of HEPG2 Cells

Abstract: Quantum dots (QDs) have different properties: high electron density, magnetic moment, phosphorescence, photoluminescence (fluorescence), and strong optical absorption. The layer or ligands on the QDs surface has a vital role because they allow the stabilization and practical uses on different matrixes. Ligand exchange is a commonly carried out methodology to incorporate functional groups that alter the solubility, introduce electron transfer partners, integrate biological receptors, or improve the properties of the QDs surface. CdSSe QDs were synthesized using a microwave system using thioglycolic acid (TGA) as a sulfur source and cover agent. The TGA ligand was interchanged with cysteine (Cys), glutamic acid (GA), glutathione (GTO), glutaraldehyde (GLT), and lysine (Lys). The viability and response of the CYP1A1, CYP1A2, and CYP3A4 isoenzymes were directly measured in HEP-G2 cells after exposure to CdSSe-TGA, CdSSe-Cys, CdSSe-GA, CdSSe-GTO, CdSSe-GLT, and CdSSe-Lys. CdSSe and CdSSe-GTO (10 mg/L) decrease viability by around 65%. The response of the cytochrome isoenzymes is based on the organic ligand on the surface of the CdSSe QDs. Changes in CYP 1A1 could be related to carcinogenic xenobiotics. Fluorescence microscopy shows CdSSe QDs on and inside HEPG2 cells. The results confirm that apoptosis and necrosis are the principal mechanisms of decreased viability.