Visible-light-mediated Regioselective Synthesis of Novel Thiazolo[3,2-b][1,2,4]triazoles: Advantageous Synthetic Application of Aqueous Conditions

From a green chemistry perspective, sustainable irradiations as the power source and water as solvent have certainly grabbed the attention of chemists in recent times as these efforts reduce hazardous...

Microwave-assisted catalytic conversion of chitin to 5-hydroxymethylfurfural using polyoxometalate as catalyst

We have demonstrated an efficient conversion of chitin to 5-HMF using a microwave aided method while using polyoxometalate (POM) as catalyst and DMSO/water as solvent.

Analysis of Cyanogenic Compounds Derived from Mandelonitrile by Ultrasound-Assisted Extraction and High-Performance Liquid Chromatography in Rosaceae and Sambucus Families

An analytical method for extraction and quantitative determination of amygdalin, prunasin, and sambunigrin in plant material is described. The method is based on extraction with high-power ultrasound (UAE), with acidified water as solvent and quantification by HPLC–DAD. The best extraction conditions were: 80% sonication amplitude, 55 s extraction time, 70% duty cycle, 0.1 g sample mass, and 10 mL acidified water (0.1% perchloric acid). Once developed, the method was validated in terms of accuracy and precision. Good linearity was obtained, with correlation coefficients exceeding 0.999 and the quantification limits ranged from 2.2 μg/g (amygdalin) to 9.6 μg/g (sambunigrin). The accuracy (recovery study) ranged between 90 and 104% and the reproducibility of the method was always <2.3% (RSD). Special attention should be paid to the ratio sample/solvent in samples with potential β-glucosidase activity to avoid degradation of the cyanogenic glycosides (CNGs). The proposed method was used to evaluate the content of CNGs in kernels of Prunus genera, apple seeds, apple pomace, and different plant materials of Sambucus nigra.

Synthesis of 1,2,3–triazole compounds by click chemistry in aqueous medium and evaluation of bactericidal and antitumoral properties.

Background: Triazoles are heterocyclic synthetic compounds that have gained relevance after studies by Sharpless on regioselective methodologies for the synthesis of 1,2,3-triazole derivatives. In addition, they have a wide range of biological properties. Objective: The objective of this study is to develop a synthetic methodology aligned with the principles of click chemistry for the synthesis of 1,2,3-triazole derivatives and verify the profile of these compounds in biological assays. Methods: Initially, a model reaction was selected and an optimization study involving synthetic conditions was carried out. Using the most efficient condition, a series of compounds was developed by the reactions between 2-azido-1-phenylethan-1-one derivatives and terminal alkynes. In sequence, bactericidal and antitumoral assays were performed. Results: It was possible to synthesise ten examples using water as a sustainable solvent, in 1 hour, with good yields of 73–99%, including three compounds described for the first time. Two products presented bactericidal activity, one against the gram-negative Escherichia coli ATCC 25922 and other against the gram-positive Paenibacillus alvei CBMAI 2221. Moreover, other two triazole derivatives presented antitumoral activity for prostate and pancreas cancer cells in this screening study with the bioactivity quantified for compound 1-([1,1'-biphenyl]-4-yl)-2-(4-(p-tolyl)-1H-1,2,3-triazol-1-yl)ethan-1-one (IC50 = 132 µM). Conclusion: Herein, an efficient methodology for the synthesis of 1,2,3-triazole derivatives with high yields and using water as solvent was developed. Furthermore, some compounds presented positive results to bactericidal and antitumoral assays, justifying further exploration of these novel compounds and their biological properties.

Aqueous Phase Bromination by Micellar Solution of Sodium Dodecyl Sulfate (SDS): An Undergraduate Chemistry Experiment

Background: Bromination is a key reaction in chemical industry, since the organobromines find application in diverse fields like pharmaceuticals, dyes, fire retardants and as intermediates in chemical synthesis. Objective: To carry out green, in-situ bromination of acetanilide in aqueous medium using micellar SDS as catalyst. Methods: Bromination of acetanilide in-situ using potassium bromide as a non-corrosive source of bromine, ceric ammonium nitrate as oxidant, micellar solution of sodium dodecyl sulphate (SDS) as catalyst and water as solvent. Results: p-Bromoacetanilide was prepared in excellent yields, at room temperature, using green chemistry principles. Conclusion: The presented method provides a fast and environmentally safe route for the preparation of p-bromoacetanilide from acetanilide. It avoids the use of volatile, corrosive, and hazardous substances like liquid bromine and acetic acid. The use of water makes it safer and free from hazardous organic solvents. This reaction can be suitably adopted at the undergraduate level and may find use in the synthesis of commercially important bromo compounds.

Solvothermal synthesis and characterization of well-dispersed cerium-doped Y2SiO5 phosphor particles

Well-dispersed cerium-doped Y2SiO5 (Ce:YSO) phosphor particles with spherical morphology and good luminescence intensity have been achieved by a solvothermal method with ethanol and water as solvent media. X-ray diffraction, Fourier transform infrared spectroscopy, fluorescence spectrophotometry and transmission electron microscopy were employed to characterize the as-synthesized Ce:YSO precursor and powders. The results showed that pure-phase Ce:YSO powders with a mean particle size of about 162 nm were accurately available at 310°C and above. The fluorescence ability and persistent luminescence decay properties of the Ce:YSO powders were also studied, and the excellent fluorescence properties could be attributed to the homogeneous Ce:YSO particles obtained through the solvothermal method.

A NOVEL, SCALABLE PRODUCTION OF MULTIFUNCTIONAL NANOCOMPOSITE POLYMER FILAMENTS FOR ADDITIVE MANUFACTURING

Though a revolutionary process, additive manufacturing (AM) has left more to be desired from printed parts, specifically, improved interlayer strength and minimal defects such as porosity. To overcome these common issues, nanocomposites have become one of the most popular materials used in AM, with various nanoparticles used to achieve a variety of characteristics. The use of these technologies together allows for both to synergistically enhance the final printed parts by improving the process and products simultaneously. Here, we introduce a novel, scalable technique to coat ABS pellets with cellulose nanocrystal (CNC) bonded carbon nanotubes (CNT), to improve the adhesion between layers as well as the mechanical properties of printed parts. An aqueous suspension of CNT-CNC is used to coat ABS pellets before they are dried and extruded into filament for printing. The filament produced using this manufacturing method showed an increase in tensile and interlayer strength as well as improved thermal conductivity. This process uses water as solvent and pristine nanoparticles without the need for any functionalization or surfactants, promoting its scalability. This process has the potential to be used with various polymers and nanoparticles, which allows the materials to be specifically tailored to the end application, (i.e. strength, conductivity, antibacterial, etc.). These nanocomposite filaments have the potential to revolutionize the way that additive manufacturing is utilized in a variety of industries.

Valorization of secondary feedstocks from the agroindustry by selective catalytic oxidation to formic and acetic acid using the OxFA process

The selective oxidative conversion of seven representative fully characterized biomasses recovered as secondary feedstocks from the agroindustry is reported. The reaction system, known as the “OxFA process,” involves a homogeneous polyoxometalate catalyst (H8PV5Mo7O40), gaseous oxygen, p-toluene sulfonic acid, and water as solvent. It took place at 20 bar and 90 °C and transformed agro-industrial wastes, such as coffee husks, cocoa husks, palm rachis, fiber and nuts, sugarcane bagasse, and rice husks into biogenic formic acid, acetic acid, and CO2 as sole products. Even though all samples were transformed; remarkably, the reaction obtains up to 64, and 55% combined yield of formic and acetic acid for coffee and cocoa husks as raw material within 24 h, respectively. In addition to the role of the catalysts and additive for promoting the reaction, the influence of biomass components (hemicellulose, cellulose and lignin) into biogenic formic acid formation has been also demonstrated. Thus, these results are of major interest for the application of novel oxidation techniques under real recovered biomass for producing value-added products. Graphical abstract

To Estimate the Label claim of tablet in their combination by simultaneous estimation using UV-Visible Spectrophotometric method

Objective: The main objective of the work was to check the label claim of tablet in combination by Simultaneous estimation by UV method. Method: Spectrophotometric method development and validation are plays important role in the development and manufacture of pharmaceuticals. This Spectrophotometric method was a simple and reproducible for the quantitative determination of Paracetamol and Caffeine in tablet formulation was developed and validated in the present work. The various parameters like specificity, linearity, precision, accuracy, robustness and ruggedness were studied according to ICH guidelines. The wavelength 273nm was selected for the estimation of Caffeine using distilled water as a solvent and the wavelength 243nm selected for the estimation of Paracetamol using distilled water as solvent the drug obeyed Beer’s-Lambert’s law over the concentration range 20-120µg/ml. Recovery study was performed to confirm the accuracy of the method. The method was successfully applied for routine analysis of this drug in formulation the method were validated as pr ICH guidelines. Conclusion: A simple UV spectrophotometric method was developed for the Simultaneous determination of Paracetamol and Caffeine in tablet formulation without any interference from the excipients. The present method succeeded in adopting a simple sample preparation that achieve satisfactory extraction recovery and facilitated its application in co formulated formulation.

UV Spectrophotometric Method Development and Validation of Luliconazole in Bulk and Formulation

Objective: A new, simple, economical, sensitive, precise and reproducible UV visible spectrophotometric method was developed for the estimation of luliconazole in pure form and pharmaceutical formulation as per ICH guidelines. Method: A UV spectrophotometric method has been developed using methanol and water as solvent to determine the luliconazole in bulk and pharmaceutical dosage formulation. The λmax of luliconazole in methanol and water was found to be 297nm. Results: The drug was proved linear in the range of 3-15µg/ml and exhibited good correlation coefficient (R2= 0.9993) and excellent mean recovery (98-99%). The % RSD for intra-day and inter-day precision was found to be 1.051288 and 1.138658 respectively. The LOD and LOQ of Luliconazole was found to be 1.1168µg/ml and 3.3845µg/ml respectively. This method was successfully applied to luliconazole content in marketed brands and results were in good agreement with the label claims. Conclusion: The method was validated for linearity, precision, repeatability and reproducibility. The obtained results proved that the method can be employed for the routine analysis of luliconazole in bulks as well as in commercial formulations.