Obtaining colored antioxidant cotton and cotton/linen fabrics using green tea aqueous extract

Green tea aqueous extract was prepared and characterized regarding total flavonoids and total phenolic contents as well as antioxidant activity (assessed by ABTS method). The characterized aqueous extract was used for dyeing and functionalization of 100% cotton and cotton/linen (47%/53% and 70%/30%) fabrics. Fabric color strength (K/S) values and their antioxidant activities before and after washing were compared. The obtained results revealed that 100% cotton (GTI), 47%/53% cotton/linen (GTII), and 70%/30% cotton/linen (GTIII) fabrics have K/S values ranging between 8.33 and 10.85. After one washing cycle, these values decreased significantly. On the other hand, dyed fabrics showed excellent (100 %) ABTS radical scavenging ability which remained excellent (GTII) or decreased to medium (GTI and GTIII) levels after one washing cycle. Based on the obtained results, it can be concluded that 47%/53% cotton/linen fabric is the most suitable for functional clothing capable of trapping the free radial of oxygen species. The current paper represents a step towards a more sustainable textile industry that could undoubtedly contribute to overcoming the environmental problems caused by the textile industry

Microwave Assisted Esterification of Aryl/Alkyl Acids Catalyzed by N-Fluorobenzenesulfonimide

The susceptibility of the carbonyl group towards nucleophilic attack affords the construction of various organic compounds. Thus, investigations of carbonyl activation applying greener methodologies are highly important. In the present work, among the investigated N-halo compounds, N-fluorobenzenesulfonimide (NFSi) has been found as an efficient and selective catalyst in the reaction of direct esterification of aryl and alkyl carboxylic acids supported by microwave (MW) irradiation. The comprehensive esterification of different benzoic acids and mono-, di-and tri-carboxy alkyl derivatives was performed, whereby significant reaction time reductions were achieved. The presented method used NFSi as an easily manipulatable, non-metal, water-and air-tolerant catalyst, allowing simple synthetic and isolation procedures and energy saving, compared to conventional methodologies. Importantly, in contrast to esterification under thermal conditions, where N-halo compounds behave as pre-catalysts, in the MW-supported protocol, a distinct reaction mechanism has been proposed that assumes NFSi as a sustainable catalyst. Moreover, a scale-up of the industrially important derivative was performed

Supplementary material for the article: Lazić, A. M.; Mašulović, A. D.; Lađarević, J. M.; Valentić, N. V. Assessing the pharmacological potential of selected xanthene derivatives. Journal of the Serbian Chemical Society 2023, 88(9), 811-824. https://doi.org/10.2298/JSC230131035L

A convenient and efficient approach toward the synthesis of seven aromatically substituted xanthendiones 1‒7 and one structurally-related xanthenone 8 through condensation of dimedone and the appropriate aromatic aldehyde is reported. Further, their chemical structure was confirmed by melting points, elemental analysis, FT-IR, 1H-, 13C-NMR and UV–Vis spectroscopic methods. The relationship between the chemical structure and pharmacological activity was determined empirically using appropriate software packages and in vitro using the 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) method. The results of in silico prediction suggested that all investigated compounds possess good oral bioavailability. The results of the ABTS assay indicate that five compounds possess the ability to scavenge the ABTS•+ radical cation. Based on the comparison of the IC50 values, the activity of the compounds was found to be as follows: 6 > 1 > 7 > 2 > 8. The effects of solvent dipolarity/polarizability and solute solvent–hydrogen-bonding interactions on the shifts of the absorption maxima were rationalized by means of the linear solvation energy relationship concepts proposed by Kamlet–Taft and Catalán.Related to: [https://technorep.tmf.bg.ac.rs/handle/123456789/6809]Supplementary material for: [https://doi.org/10.2298/JSC230131035L

Voltammetric Investigation of Inclusion Complexes of the Selected Succinimides with β-Cyclodextrin and (2-Hydroxypropyl)-β-Cyclodextrin

The inclusion complexes of the selected, potentially biologically active, succinimides with β-cyclodextrin (βCD) and (2-hydroxypropyl)-β-cyclodextrin (HPβCD) were prepared. the formation of the inclusion complexes of the investigated monophenyl and diphenyl succinimide derivatives was confirmed using attenuated total reflection (ATR) study. Their electrochemical behavior was examined by cyclic voltammetry (CV) and square wave voltammetry (SWV) in 0.05 M NaHCO3 on a gold electrode. The stability constants for compound 1 were determined by cyclic voltammetry and calculated as KβCD = 350.87 M–1 and KHPβCD = 250.67 M–1. The SWV measurements reveal well defined peak at potential Ep = ~ 60 mV and the higher currents at Ep for both inclusion complex of the succinimides compared to the free compounds. The impact of chlorine atom in the phenyl moiety of succinimide derivatives on the activity in electrooxidation reaction is presented. Among the studied succinimides, according to SWV measurements, the most active is the monophenyl succinimide derivative (compound 1) in complex with βCD. The difference of peak current of compound 1 + βCD compared to compound 1 + HPβCD and free compound is 6.3 and 35.2 μA cm–2, respectively

Addressing the environmental problems of wastewater: reducing the pollution while providing multifunctional wool fabrics

The reduction of water pollution represents one of the priority topics of the EU’s goal to achieve climate neutrality by 2050. Considering this, the concept of reusing the same dyebath for multiple dyeing cycles is proposed. For this purpose, two pyridinium-based azo pyridone dyes with improved solubility and affinity towards different fibers, are used for dyeing wool fabric. It is demonstrated that the dye concentration in wastewater could be reduced up to four times by recirculation of the same dyebath 5 times. The dyed fabrics obtained in each cycle are further characterized regarding color strength (K/S) and ultraviolet protection factor (UPF), while their antioxidant potential is evaluated by ABTS (2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)) test. The results revealed that the proposed concept could be used for obtaining multifunctional wool fabrics by following the principles of sustainable development of reducing the effluent load in wastewater

Obtaining Polysaccharide-Based Fabrics with Improved Moisture Sorption and Dye Adsorption Properties

Featured Application: This work has a potential application in biocarpet engineering, which involves the use of cyanobacterial crusts either in the rehabilitation of damaged land surfaces or to combat desertification. Attempts to apply cyanobacterial crusts have not been completely successful so far because the growth of the initial inoculum requires more moisture than arid and semiarid environments can provide. To accelerate the development of the inoculum, it is necessary to provide additional moisture for the growth of cyanobacterial cells. Controlled water delivery could be achieved by using moisture-retentive material that is applied together with the inoculum in the treatment of damaged surfaces. Biocarpet engineering has the potential to solve not only some problems of damaged surfaces and desertification but also reduce and prevent air and water pollution caused by erosion. Raw jute fabric was treated with 0.5, 1.0, or 2.0% chitosan solution to improve its sorption properties (evaluated through the moisture sorption and adsorption of textile dye Reactive Orange 16 (RO 16)), which are essential for fabric utilization as geo-prebiotic polysaccharide support that should provide the necessary water for the growth of cyanobacterial communities in biocarpet engineering. Chitosan-treated fabrics possessed 39–78% higher moisture sorption values than the untreated ones. Concerning the dye adsorption, with the increase in its initial concentration, the adsorption potential of raw and fabrics treated with 0.5 or 1.0% chitosan solution was increased up to 1.9 times. The dye adsorption onto these fabrics was exothermic and enthalpy driven. By increasing the chitosan solution percentage up to 1.0%, fabric adsorption potential increased up to 2.2 times. An inverse relationship was observed in the case of the fabric treated with 2.0% chitosan solution, its adsorption potential decreased with increasing the initial dye concentration and temperature due to the different dominant binding interactions. Concerning the contact time, dye adsorption onto fabric treated with 1.0% chitosan solution was rapid in the first 2 h, while the equilibrium was attained after 4.5 h. The isotherm and kinetic data were represented by the Langmuir model and the pseudo-second-order kinetic model, respectively

2-OXO-1,2,3,4-tetrahydropyrimidine-azo-pyridone dye : a potential application as new green-emitting fluorescent probe

Molecular imaging is a relatively new research field, which has demonstrated great potential, especially in clinical oncology – from drug development to cancer early detection. The key of fluorescence imaging is the construction of fluorescent probe which is composed of two parts, the recognition groups to recognize cancer cells, and fluorophores to signal the recognition events. In this research, the structure of new fluorescent azo dye based on 2-oxo-1,2,3,4-tetrahydropyrimidin and 2-pyridone moieties has been reported. The absorption and emission properties of the investigated azo dye have been studied using UV-Vis and fluorescence spectroscopy. The obtained results suggest that studied dye meets the requirements for new green-emitting fluorescent probe, suitable for further application in biomedical researches

Recovering the Soybean Hulls after Peroxidase Extraction and Their Application as Adsorbent for Metal Ions and Dyes

This study is aimed at extending the soybean hulls' lifetime by their utilization as an adsorbent for metal ions (Cd2+ and Cu2+) and dyes (Reactive Yellow 39 (RY 39) and Acid Blue 225 (AB 225)). ATR-FTIR spectroscopy, FE-SEM microscopy, and zeta potential measurements were used for adsorbent characterization. The effect of the solution's pH, peroxidase extraction, adsorbent particle size, contact time, the pollutant's initial concentration, and temperature on the soybean hulls' adsorption potential was studied. Before peroxidase extraction, soybean hulls were capable of removing 72% Cd2+, 71% Cu2+ (at a pH of 5.00) or 81% RY 39, and 73% AB 225 (at a pH of 3.00). For further experiments, soybean hulls without peroxidase were used for several reasons: (1) due to their observed higher metal ion removal, (2) in order to reduce the waste disposal cost after the peroxidase (usually used for wastewater decolorization) extraction, and (3) since the soybean hulls without peroxidase possessed significantly lower secondary pollution than those with peroxidase. Cd2+ and Cu2+ removal was slightly increased when the smaller adsorbent fraction (710-1000 μm) was used, while the adsorbent particle size did not have an impact on dye removal. After 30 min of contact time, 92% and 88% of RY 39 and AB 225 were removed, respectively, while after the same contact time, 80% and 69% of Cd2+ and Cu2+ were removed, respectively. Adsorption of all tested pollutants follows a pseudo-second-order reaction through the fast adsorption, intraparticle diffusion, and final equilibrium stage. The maximal adsorption capacities determined by the Langmuir model were 21.10, 20.54, 16.54, and 17.23 mg/g for Cd2+, Cu2+, RY 39, and AB 225, respectively. Calculated thermodynamic parameters suggested that the adsorption of all pollutants is spontaneous and of endothermic character. Moreover, different binary mixtures were prepared, and the competitive adsorptions revealed that the soybean hulls are the most efficient adsorbent for the mixture of AB 225 and Cu2+. The findings of this study contribute to the soybean hulls' recovery after the peroxidase extraction and bring them into the circular economy concept

Obtaining colored antioxidant cotton and cotton/linen fabrics using green tea aqueous extract

Abstract Green tea aqueous extract was prepared and characterized regarding total flavonoids and total phenolic contents as well as antioxidant activity (assessed by ABTS method). The characterized aqueous extract was used for dyeing and functionalization of 100% cotton and cotton/linen (47%/53% and 70%/30%) fabrics. Fabric color strength (K/S) values and their antioxidant activities before and after washing were compared. The obtained results revealed that 100% cotton (GTI), 47%/53% cotton/linen (GTII), and 70%/30% cotton/linen (GTIII) fabrics have K/S values ranging between 8.33 and 10.85. After one washing cycle, these values decreased significantly. On the other hand, dyed fabrics showed excellent (100 %) ABTS radical scavenging ability which remained excellent (GTII) or decreased to medium (GTI and GTIII) levels after one washing cycle. Based on the obtained results, it can be concluded that 47%/53% cotton/linen fabric is the most suitable for functional clothing capable of trapping the free radial of oxygen species. The current paper represents a step towards a more sustainable textile industry that could undoubtedly contribute to overcoming the environmental problems caused by the textile industr

Optical and antioxidative properties of 5-(2,6-Dimethylphenyl)- 6-Hydroxy-4-Methyl-2-Oxo-1,2-Dihydropyridine-3-Carboxamide

A new heterocyclic azo dye 5-(2,6-dimethylphenyl)-6-hydroxy-4-methyl-2-oxo-1,2- dihydropyridine-3-carboxamide was synthesized and structurally characterized by elemental analysis, FTIR, 1H and 13C NMR spectroscopy techniques. These analysis have confirmed that synthesized dye exists in the tinctorial strongest tautomeric form, hydrazone form. The dye is characterized by reflection spectrum, while absorption and emisson spectra are recorded in nine different solvents. The antioxidant activity of the synthesized dye has been chemically tested and has been shown to have great potential as an antioxidant molecule