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Laccase-Catalyzed Oligomerization of Esculin: Effect of Key Reaction Parameters and Evaluation of Oligoesculin Antioxidant and Skin Prebiotic Capacity
No full textEnzymatic oligomerization of flavonoids enables the synthesis of biomolecules with different structures and improved physicochemical and biological properties and can therefore broaden their application in industry. In this study, the influence of the key reaction parameters temperature, solvent, substrate, and enzyme concentrations on the synthesis of esculin oligomers was investigated. The reaction was optimized using response surface methodology (RSM) in order to obtain the highest products’ concentration and specific products’ yield (per mass of enzyme). Mass spectrometry revealed that oligomers with a degree of polymerization of up to 4 were synthesized in which dimers were the most abundant, while the NMR analysis of the esculin dimer product showed that C8-C8 link between two esculin units was formed. Maximum products’ concentration was obtained at 60 °C, in 14% (v/v) methanol, 7 mg/mL of esculin, and 54.6 U/L of laccase after 7 h, while the optimal conditions for specific products’ yield differed in the aspect of optimal laccase concentration which was 19 U/L for this output. Synthesized esculin oligomers exhibited higher iron chelating and cupric reducing antioxidant capacities and similar or even superior free radical scavenging activity compared to monomeric esculin. Moreover, the mixture of synthesized esculin oligomers has shown a promising potential to be used as a skin prebiotics, suggesting novel applications in skincare industries
LC-MS-based metabolomics for detecting adulteration in Tribulus terrestris-derived dietary supplements
No full textThe widespread usage of Tribulus terrestris dietary supplements has elicited concerns over product authenticity and possible adulteration. This research utilized an untargeted liquid chromatography-high resolution mass spectrometry (LC-HRMS) metabolomics methodology to assess the composition of T. terrestris-derived supplements. Authentic plant materials, simulated adulterated samples, and commercial products were analyzed using principal component analysis (PCA), orthogonal partial least squares discriminant analysis (OPLS-DA), and a convolutional neural network tool. The presence of PDE5 inhibitors and anabolic steroids in spiked samples was confirmed. Certain commercial products included undisclosed green tea and citrus-derived chemicals, likely incorporated to amplify stimulant effects and support testosterone-enhancing claims. Additionally, spirost-4-ene-3,12-dione was recognized as an indicator of possible steroidal saponin decomposition resulting from storage or processing conditions. This study illustrates the efficacy of LC-HRMS metabolomics in detecting supplement adulteration and emphasizes the need for rigorous quality control protocols to guarantee customer safety and product integrity
Optimizing alginate immobilization of food-derived C-phycocyanin: structural and functional characterization
No full textC-phycocyanin (C-PC) represents a significant component of thecyanobacteria Arthrospira platensis (Spirulina) biomass. Beyond its nutritionalvalue, this protein exhibits numerous beneficial biological activities. Acovalently attached chromophore, phycocyanobilin, gives C-PC a blue color,enabling its use as a natural food colorant. Additionally, phycocyanobilinexhibits various bioactive properties, including metal-binding activities. A keydrawback to the broader industrial application of C-PC is its poor stability.Alternative food formulations using natural polymers as carriers and activecomponents have recently gained considerable scientific attention. This paperdescribes optimized conditions for C-PC immobilization using alginate. Thestructural stabilization of immobilized C-PC was analyzed under hightemperature (60°C) and high pressure (450 MPa). The storage stability ofimmobilized C-PC in dried alginate beads was tested by keeping the samples at4°C for one month. The potential application of immobilized C-PC for theremoval of mercury ions was also investigated. Alginate immobilization provedeffective in stabilizing C-PC, significantly preserving its structure duringprolonged storage, thermal treatment, and high-pressure exposure. Under thetested conditions, 97% of Hg2+ ions were removed by immobilized C-PC.Overall, this study optimized the procedure for enhancing C-PC stability throughalginate immobilization and broadened its potential applications in food andbioremediation industries
Status elemenata u uzorcima seruma pacijenata sa dijagnostikovanom cervikalnom intraepitelnom neoplazijom
No full textCiljevi ove studije su da se odredi status elemenata u uzorcima seruma osoba sa dijagnsotikovanom cervikalnom inraepitelnom neoplazijom, da se porede vrijednosti elemenata u uzorcima seruma kontrolne grupe ispitanika i uzorcima seruma osoba kod kojih je dijagnostikovana CIN i da se utvrdi da li postoje razlike u tim vrijednostima
Nanoplastics selectively bind and unveil novel ragweed pollen allergens
No full textThe pollen of Ambrosia artemisifolia, ragweed pollen, is widespread cause of respiratory allergic reactions. The aim of the work was to provide evidence of corona formation and its properties on NP particles in simulated lung fluids (SLF), simulating event of pollen and NP co-exposure through respiration.
A. artemisifilia pollen is chosen as model system for investigation of NPs interactions with respiratory allergens. Its extract was prepared under mild conditions and short exposure to water, simulating rainfall burst of pollen particles. The binding of Ambrosia pollen allergens to NPs (PP and PET, 100 nm) was monitored in simulated lung fluids (SLF) by corona formation and mass spectrometry, while the effect of NPs on Ambrosia pollen proteins structure was studied by CD spectroscopy. Corona formation was analyzed by glycoproteins staining and immunoblotting with Ambrosia pollen allergic patients sera. Relevant NPs binding proteins of ragweed were also identified by shotgun proteomics in subpollen particles.
Ambrosia pollen NPs corona is composed of specific allergenic proteins in SLF conditions showing highly selective binding of ragweed pollen proteins from the extract. Composition of soft and hard coronae is different between nanoPET and nanoPP particles. Hard corona of nanoPP is dominated by a low Mw glycopeptide(s). We have confirmed that 28-32 kDa proteins of hard corona are PCC13-62-like protein and plant basic secretory protein. We have also confirmed their presence in subpollen particles.
Specific adsorption of novel ragweed proteins and glycopeptides to NPs hard corona have been shown, allowing us to suggest those IgE-binding proteins and peptides to be major biocorona component of NPs. Our data provide insight into molecular events occurring during co-exposure of NPs and allergens. Selective binding of allergenic proteins to NPs may during co-exposure change the route of allergen exposure to the immune system and modulate allergic reactions.
Disclaimer/Disclosure: Acknowledgment. Funding from Horizon 2020, No965173, IMPTOX, by Ministry of Science, Innovation and Technological Development, Republic of Serbia, grant No451-03-66/2024-03/200168 and Serbian Academy of Sciences and Arts, GA F-26.The lecture was delivered by Tanja Ćirković Veličković, Full Professor at the University of Belgrade – Faculty of Chemistry
Green Extraction of Bioactives from Curcuma longa Using Natural Deep Eutectic Solvents: Unlocking Antioxidative, Antimicrobial, Antidiabetic, and Skin Depigmentation Potentials
No full textThis study evaluates the efficiency of 20 Natural Deep Eutectic Solvents (NADES)
formulations for extracting curcuminoids and other bioactive compounds from turmeric
and emphasize their ability to preserve and enhance antioxidant, antimicrobial, antidiabetic,
and skin depigmentation effects. The NADES formulations, prepared using choline chloride (ChCl) combined with sugars, carboxylic acids, glycerol, amino acids, urea, polyols,
and betaine, were assessed for their extraction efficiency based on the total phenolic content
and curcumin concentration. Fourier transform infrared spectroscopy was employed to
characterize the synthesized NADES and confirm their chemical composition. Bioactivity
evaluations included antioxidant assays (ABTS and DPPH), antidiabetic tests (α-amylase inhibition), antimicrobial assays, and skin depigmentation (tyrosinase inhibition). The results
demonstrated that NADES significantly enhanced the extraction efficiency and bioactive
properties of turmeric extracts compared to water as a conventional green solvent. NADES
18 (ChCl/1,2-propanediol/water 1:1:1) and NADES 19 (glycerol/betaine/water 1:1:3) exhibited the highest extraction yields, with curcumin concentrations of 30.73 ± 1.96 mg/g and
31.70 ± 2.02 mg/g, respectively, outperforming water (26.91 ± 1.72 mg/g), while NADES
17 (ChCl/1,2-propanediol/water 0.5:3:0.5:5) and NADES 20 (glycerol/lysine/water 1:1:3)
exhibited the most potent antioxidant activity. Furthermore, NADES 14 (ChCl/lactic
acid/water 1:2:5) demonstrated the strongest tyrosinase inhibition (98.7%), supporting its
potential for skin-brightening applications, including notable α-amylase inhibition exceeding 90%. This study aligns with the principles of green chemistry, as NADES are effective
and sustainable solvents for natural product extraction. The presenting benefits of improved
extraction efficiency and enhanced bioactivities position NADES as a promising and ecofriendly approach for developing efficient bioactive compound extraction methodologies
Recent Progress in Green Sample Preparation for Improved Plant-Based Natural Product and Phenolic Compound Analysis
No full textPhenolic compounds, secondary metabolites, are essential products of plant metabolism. They are characterized by one or more aromatic rings attached to hydroxyl groups and are categorized into phenolic acids, flavonoids, tannins, stilbenes, and lignans. These compounds play critical roles in plants, contributing to pigmentation, astringency, UV protection, and defense against pests and pathogens. Widely distributed in fruits, vegetables, and other matrices, they are also extracted from waste and byproducts of the food production chain, aligning with sustainable practices. Research on phenolic compounds is extensive, driven by their significant health benefits and diverse biological activity. Extraction is the initial and critical step in their study, with efficiency influenced by factors such as the extraction method, plant matrix properties, solvent choice, temperature, pressure, and time. Recent years have seen a surge in studies on both conventional and innovative extraction methodologies, with a growing emphasis on green technologies. This review provides a comprehensive overview of advancements in green sample preparation (GSP) techniques within the framework of green analytical chemistry (GAC). It highlights strategies to minimize environmental impact, including the use of micro-techniques, assisted extraction methods, and eco-friendly solvents from renewable and non-toxic sources. Experimental design methods for optimizing phenolic compound yields are also discussed. Additionally, the review presents tools for assessing the greenness of sample preparation techniques, focusing on their environmental and operational improvements
Interdisciplinary projects for developing environmental literacy and environmental identity of primary school students
No full textEnvironmental literacy and environmental identity are the key concepts of Education for Sustainable Development. Environmental literacy refers to the understanding of basic principles of how the environment functions, critical thinking related to environmental issues and responsible decision-making based on the acquired knowledge and pro-environmental behavior. Environmental identity, on the other hand, refers to the relationship of an individual with the nature and the sense of responsibility for preserving it.
One of the quality standards of educational institutions in the Republic of Serbia is their active involvement in promotion of sustainable development. This is achieved through the education of students on ecological topics and development of their responsible attitude towards the natural environment. Within this context, the school and the teacher play a crucial role in designing and implementing activities that stimulate environmental literacy and develop students’ environmental identity. This can be achieved by project-based learning and activities that interrelate theoretical knowledge and its application in real life. Project-based activities involve the examination of real problems, planning and applying solutions to the identified problems, student collaboration and the application of interdisciplinary approach that enables integration of the acquired knowledge into practical results.
The aim of this paper is to present the scenario of a project-based activity entitled Practical measures for sustainable development in school in which students combine the contents of biology, chemistry and geography. The outputs of such a project activity enable not only the development of knowledge and skills in various disciplines but also strengthen the students’ sense of belonging to the community and their responsibility towards the natural environment. This paper emphasizes the significance of project-based learning as an efficient educational model that encourages young generations to contribute to sustainable development and build their environmental identity
Holmium Metal Nanoparticle PbO2 Anode Formed by Electrodeposition for Efficient Removal of Insecticide Acetamiprid and Improved Oxygen Evolution Reaction
No full textThis work examines the possibility of using a PbO2-based electrode doped with the rare-earth metal holmium in the field of oxygen evolution and the development of an efficient method for the degradation of acetamiprid. Acetamiprid is a widely used insecticide and, as such, it very often reaches waterways, where it can cause many problems for wildlife and the environment. X-ray powder diffraction analysis, Raman spectroscopy, and energy-dispersive X-ray spectroscopy results confirmed the structure of Ti/SnO2-Sb2O3/Ho-PbO2, while the morphology of its surface was investigated by scanning electron microscopy with energy-dispersive X-ray spectroscopy. Ti/SnO2-Sb2O3/Ho-PbO2 showed good OER activity in alkaline media with a Tafel slope of 138 mV dec−1. The Ti/SnO2-Sb2O3/Ho-PbO2 electrode shows very good efficiency in removing acetamiprid. By optimizing the degradation procedure, the following operating conditions were obtained: a current density of 20 mA cm−2, a pH value of the supporting electrolyte (sodium sulfate) of 2, and a concentration of the supporting electrolyte of 0.035 M. After optimization, the maximum efficiency of removing acetamiprid (10 mg L−1, 4.5 × 10−5 mol) from water was achieved, 96.8%, after only 90 min of treatment, which represents an efficiency of 1.125 mol cm−2 of the electrode. Additionally, it was shown that the degradation efficiency is strictly related to the concentration of the treated substance
Anti-Aging Potential of Illyrian Iris Rhizome Extract: Preliminary Chemical and Biological Profiling and Chemosensor Analysis via GC/MS and UHPLC-DAD-MS/MS Combined with HPTLC Bioautography
No full textIllyrian iris (Iris pallida subsp. illyrica (Tomm. ex Vis.) K.Richt.) is a rhizomatous geophyte, an endemic species (subspecies), occurring within a limited range along the eastern coast of the Adriatic Sea. The study presents the first in-depth chemical and functional investigation of its rhizome extracts using both conventional and greener solvents, as well as essential oil (EO) via hydrodistillation, employing gas chromatography-mass spectrometry (GC/MS) and ultra-high-performance liquid chromatography-diode array detector-tandem mass spectrometry (UHPLC-DAD-MS/MS) for metabolic fingerprinting, which was further interpreted through a chemosensory lens. High-performance thin-layer chromatography (HPTLC) bioautography (HPTLC-DPPH/ HPTLC-Tyrosinase) was applied for the first time to this species, revealing zones of bioactivity. HaCaT cell viability and spectrophotometric assays were employed to further evaluate the cosmetic potential. Results showed a distinctive volatile profile of EO, including, to the best of our knowledge, the first identification of a silphiperfol-type sesquiterpenoid in the Illyrian iris rhizome. UHPLC-DAD-MS/MS and HPTLC fingerprinting further supported solvent-dependent differences in metabolite composition. Notably, acetone, ethyl acetate, and ethanol extracts exhibited similar chemical profiles, while greener extracts showed more divergent patterns. The results provide a foundation for the future exploration of Illyrian iris in sustainable cosmetic applications, emphasizing the need for further in vitro and in vivo validation