Journal of the Serbian Chemical Society

Theoretical evaluation of pectin therapeutic potential in relation to degree of methylation

2024-05-13T10:31:09+02:00

Pectin is the focus of scientific interest due to both its physicochemical and biochemical properties, as well as its non-toxic nature. Methylation of pectin is a natural process that exists as part of the cell wall defence system against various pathogens. In this study the docking analysis was conducted to predict if methylation o affects the anticancer and antimicrobial properties of pectin and twhat extent. Four pectin derivatives with varying degrees of methylation and two sets of biomolecules were used. The first set included enzymes responsible for anticancer activity (HMGR, the AGE Receptors, tumour protein p53, and Oncogenic Phosphatase SHP2), while the second set included those for antimicrobial activity (Salmonella Typhi TtsA, Pseudomonas aeruginosa Earp, Streptococcus mutans MetE, and Staphylococcus aureus Cas9). The results indicated that the degree of methylation does not play a decisive role in the mentioned activities. because all bind to the same sites with similar binding energies. Additionally, it was shown that pectin derivatives have a higher binding affinity towards DNA than towards enzymes. Only the fully methylated derivative exhibited different behaviour, binding to a different binding site in the case of Streptococcus mutans MetE.

Synthesis and in vitro study of redox properties of pyrrole and halogenated pyrrole derivatives

2024-07-16T22:15:59+02:00

The redox balance plays a crucial role in maintaining biological processes under normal conditions. Antioxidants inhibit and reduce harmful oxidation processes, while pro-oxidants can act as anti-cancer agents by promoting ROS-mediated cell death. The aim of this study is to compare the redox properties of seven newly synthesised tribromopyrrole derivatives with three novel and four previously synthesized non-halogenated analogues in an in vitro model (in human serum) and with exogenously induced oxidative stress. The obtained values of their oxy scores (OS) were compared and the result showed that four non-halogenated pyrrole derivatives with secondary amide group M2, M10, M11 and M12 have lower OS values than Trolox, a water-soluble analogue of vitamin E with proven antioxidant properties. All four compounds show strong resistance to oxidative stress, which is reflected in the maintenance of negative OS values when exposed to exogenous oxidative stress using TBH in the reaction mixture. This capability to resist invading ROS should be expected also in an endogenous environment, where constant prooxidant production takes place at a low, homeostatic level, but even more so in pathological conditions. The tribrominated derivative M15 showed prooxidant activity with a significantly higher OS value than all other compounds tested. The comparison of the dose-response of Trolox and the five compounds with the lowest OS also shows that compounds M2, M7 and M10 have better antioxidant activity than Trolox.

Chemical composition and bioactivities of Phellinus pini extracts and quality evaluation of healthy drinks prepared from the mushroom

2024-08-10T14:43:11+02:00

Phellinus pini, a mushroom species found in East Asian countries, is commonly consumed as a medicinal beverage known for its stomach-warming effects and purported ability to alleviate pain and tumours. In this study, P. pini was extracted using different methods (hot water, sonication, microwave, and soaking). The extracts were analysed for phenolic and polysaccharide contents. Additionally, the extracts were evaluated for their antioxidant potential and ability to inhibit albumin denaturation. The results demonstrated that the extract obtained with hot water extraction contained the greatest amount of phenolics (105.98±0.53 mg GAE/mL). The hot water and microwave extraction methods showed more effective in extracting polysaccharide from the mushroom. Moreover, the extract from the ultrasound extraction method presented the strongest antioxidant activity by scavenging DPPH and ABTS radicals by 41.26 and 97.84 %, respectively while the hot water extract exhibited the most potent ability to inhibit albumin denaturation by 96.40 %. Among the four healthy drinks formulated, the formulation with the greatest proportion of P. pini extract contained the highest total phenolic content, antioxidant activity, and the most favorable sensory overall liking. The described findings deepen our understanding of the chemical composition and potential health-promoting properties of P. pini, as well as revealing new potential applications for the mushroom in the food and nutraceutical industries.

Malachite green removal by Eryngium caeruleum ash

2024-07-21T23:25:20+02:00

In this study, malachite green (MG) has been successfully removed from an aqueous solution with the use of Eryngium caeruleum ash as an adsorbent. The influence of effective factors on the dye removal process, like contact time, the initial concentration of dye, amount of adsorbent, temperature, and pH, has been studied. The results revealed that the optimal malachite green adsorption occurred at pH 7, 120 min of contact time, 0.01 g of adsorbent, and 100 mg L^-1 of initial dye concentration. Furthermore, the adsorption results follow the Langmuir isotherm with a correlation coefficient (R² = 0.98), (q_max = 476.19 mg g^-1), and pseudo-second order kinetic (R² = 0.97). Endothermic and spontaneous adsorption were implied by the positive ∆H⁰, ∆S⁰, and negative ∆G⁰. Therefore, in order to remove MG from aqueous solutions, Eryngium caeruleum ash can be exploited as a low-cost and environmentally friendly adsorbent.

The effects of silver nanoparticles synthesized with an aqueous extract of Agrimonia eupatoria L. on winter wheat and barley varieties

2024-11-07T14:36:02+01:00

Silver nanoparticles represent a potential solution for mitigating the negative effects of temperature stress on cereals. This study investigates the impact of silver nanoparticles on winter varieties of wheat and barley during the tillering phase, focusing on proline concentration, antioxidant activity and extract yield under winter field conditions. Silver nanoparticles (AgNPs) were synthesized using a green method with an aqueous extract of the plant Agrimonia eupatoria L. (fam. Rosaceae). Two winter cereal varieties, Simonida (Triticum aestivum L.) and Nonius (Hordeum vulgare L.), were foliar treated with 5 mg mL^-1 and 10 mg mL^-1 AgNPs-H₂O. The experiment lasted for 10 days, during which the minimum recorded temperature was –7 °C under field conditions. The proline concentration was increased in both varieties treated with nanoparticles compared to the controls. Antioxidant activity was assessed using the DPPH method for both treated and untreated samples, with ascorbic acid used as a positive control. Antioxidant activity has increased in all treated samples compared to the untreated samples. Only specific concentrations of AgNPs-H₂O increased the extract yield. Based on these results, our study emphasizes the potential of AgNPs-H₂O to improve the tolerance of winter cereals to low temperatures.

Efficiency of physical-chemical treatment of wastewater of the paper and cardboard factory

2024-01-12T23:21:29+01:00

The purpose of the work is to study the wastewater treatment of a cardboard and paper factory in the Khmelnytskyi region using physico-chemical methods, namely coagulation and oxidation, to increase the efficiency of removing organic pollutants according to COD and BOD indicators. The use of coagulation and chlorination methods, before biological treatment in aeration tanks, was proposed. Alumofloc 18% was used as a coagulant, PAA was used as a flocculant, and sodium hydroxide was used as an alkalizing reagent. The study was conducted on a mixture of industrial and sewage wastewater with COD and BOD5 – 3200 and 1575 mg L^–1, respectively, and on industrial wastewater with COD and BOD5 – 4480 and 1960 mg L^–1, respectively. The effects of reducing COD and BOD5 indicators in the first case after coagulation were 30 and 40%, after chlorination – 37.82 and 43.18%, respectively, and in the second after coagulation – 28.58 and 47.25%, respectively. The effects of wastewater treatment of a cardboard and paper factory using coagulation and oxidation methods will allow for a reduction in the concentration of organic substances according to COD and BOD indicators before the biological treatment of wastewater in aeration tanks and also will ensure an increase in the efficiency of biological treatment.

Refinement technique for nanocellulose extraction from corn cobs as a green material for environmental sustainability

2024-04-17T23:40:44+02:00

Corn cob and other types of agricultural biomass waste are abundant and have several potential uses as renewable materials. A unique extraction approach for producing nanocellulose materials with precise control, scalability, and promising practical applications has been presented. Nanocrystalline cellulose was produced from corn cobs by mechanical treatment with ultrasonic technology, room temperature extraction for 30 min, and sulfuric acid concentrations ranging from 30 % to 0% w/v. Nanocellulose has been effectively extracted from maize cobs with comparatively high yields and crystallinities ranging from 63.55% to 71.76%. The TEM data demonstrate the production of fiber nanoparticles with a size range of 15.3 nm to 2.1 nm. Simultaneously, SEM results match TEM findings. SEM pictures indicate smaller nanoparticles as sonication duration rises, but particle size does not vary with acid content. XRD analysis indicates an increase in the amount of crystalline cellulose in nanocellulose, demonstrating a notable transformation of cellulose. Nanocellulose and cellulose had similar FTIR spectra, distinct from the basic material of corn cobs. The FTIR analysis showed that the NaOH and subsequent bleaching treatments eliminated most hemicellulose and nearly all lignin throughout the conversion process. This work introduces a method for extracting nanocellulose from corncob waste utilizing standard ultrasonic technology under moderate conditions, at a cheap cost, in an ecologically responsible manner, with a high yield while maintaining its integrity.

Selected phytochemicals as potent acetylcholinesterase inhibitors: An in silico prediction

2024-05-09T19:14:46+02:00

In recent times, there has been a notable increase in the widespread presence of Alzheimer’s disease. The disease could be controlled by the inhibition of acetylcholinesterase, an enzyme associated with the degradation of acetylcholine. Plants have been used to treat neurogenerative diseases and their phytochemicals could act as acetylcholinesterase inhibitors, impeding the protein’s catalytic activity. This study includes a computational assessment of phytocompounds as potent inhibitors of the enzyme. The molecular docking calculations revealed binding affinities of -50.651, –49.446 , –48.400, –47.977, –47.839 and –47.417 kJ/mol for allanxanthone B, stigmasterol, 5'-O-methyl dioncophylline D, ismailin, wistin and dioncophylline C2, respectively, indicating firm binding of these molecules with the receptor. Donepezil (a native and FDA-approved drug) exhibited a binding affinity of –46.789 kJ/mol, which was significantly lower than that of the proposed phytochemicals. The successful candidates demonstrated good stability of the complex with the protein, showing smooth RMSD of ligands below 6 Å from the 200 ns molecular dynamics simulation. The thermodynamic stability from the MMPBSA method indicated the sustained spontaneity and feasibility of the adducts. Thus, the proposed candidates could be used as remedies for Alzheimer’s disease after the experimental verification for their safety and efficacy.

Chlorogenic acid with cytotoxic activity and other constituents from Anacyclus valentinus from Algeria

2024-06-13T07:42:39+02:00

Anacyclus valentinus is a Saharan plant belonging to the Asteraceae family. This study identified and determined the structure of isolated compounds obtained from unrefined extract of A. valentinus. Their cytotoxic effects on two human cancer cell lines were examined. The extract of the aerial part of A. valentinus was fractioned by solid phase extraction (SPE). The fractions obtained were analysed by NMR spectroscopy and HPLC-DAD–MS. This is the first cytotoxic investigation of A. valentinus. The extracts of the plant were prepared, and their cytotoxic effects on two human cancer cell lines (A549, human lung adenocarcinoma; HepG2, hepatocellular carcinoma) were examined using the MTT assay. Several compounds have been identified. The results illustrated two newly identified compounds: chlorogenic acid and the β-glucosides derivative. In addition, C-glycosides (2 isomers of apigenin) were detected in the genus Anacyclus. The IC₅₀ values of unrefined extracts of the aerial parts of A. valentinus against the A549 cell line were determined as 19.79 µg/mL. The values for the HepG2 cell line were 32.63 µg/mL. Chlorogenic acid was showed the highest cytotoxic activities on the A549 and HepG2 cell lines with IC₅₀ values of 13.59 and 12.84 μg/mL, respectively.

Enhancing fire resistance in wood with high-water retention silica gel: A promising flame-retardant solution

2024-06-24T09:32:57+02:00

This study aims to evaluate water retention and flame-retardant properties of silica gel prepared using anionic polyacrylamide (HPAM), gluconate-delta-lactone (GDL), and aluminum citrate (AlCit). Silica gel samples were synthesized with sodium silicate (8 wt%), sodium bicarbonate (4 wt%) and varying concentrations of HPAM (0.2-0.8 wt%) and GDL (0.1-0.3 wt%). The prepared gels were characterized using XPS, XRD, FTIR, and TGA. Optimal water retention capacity was achieved with 0.4 wt% HPAM and 0.2 wt% GDL. Compared to traditional gels, silica gel has more surface water molecules due to the additional hydrophilic groups and the amorphous nature of silica. At high temperatures, silica forms a layer with the charcoal from treated wood combustion, inhibiting oxygen penetration and minimizing further combustion. After combustion at 500 °C, the mass loss of wood treated with silica gel is 36-53% less than untreated wood, indicating greater weight retention and demonstrating silica gel's effectiveness in preventing continued burning.