Teucrium montanum has widespread use in folk medicine on the Balkan peninsula. In order to scientifically justify this use, the composition and biological activity of aqueous, ethanol, and acetone extract were investigated in this study. Moreover, acetone and ethanol extracts were obtained from the plant material previously exhausted by water extraction. A total of 27 compounds were detected in extracts by UHPLC-DAD-MS/MS analysis, with all of them present in acetone and ethanol extracts. Consequentially, the acetone and ethanol extracts showed higher contents of total phenols of 23% and 18%, respectively, compared to the water extract. The results indicated high biological potential in the investigated extracts. Among all extracts, the aqueous extract showed slightly higher antimicrobial potential, especially against Gram-positive strains, probably due to the release of components soluble in water from the dry unexhausted plant material. On the other hand, the acetone and ethanol extracts had significantly higher antioxidative (by 20%), anti-inflammatory activity (up to 3 and 4 times higher, respectively), and α-glucosidase inhibitory potential (3 times higher) than the aqueous extract. The results of this investigation reveal the great potential of the use of T. montanum in various branches of food, cosmetics, and the pharmaceutical industry. An important part of this research is a confirmation that, once exhausted by water extraction, for example by hydrodistillation, T. montanum plant material can be reused for obtaining valuable products with a wide range of biological activities.

Background: Microbial contamination of fresh beef remains a major challenge in the meat industry, driving the need for effective natural preservation strategies that can extend shelf life while meeting consumer demand. Methods: Chitosan-based edible coatings enriched with free and nanoencapsulated Ocimum basilicum L. essential oil at concentrations of 0.25%, 0.5% and 1% were evaluated for their efficacy on fresh beef during 20 days of refrigerated storage. Microbiological parameters, including total bacterial count, lactic acid bacteria, psychrotrophic bacteria, and Pseudomonas spp., as well as physicochemical indicators such as pH and thiobarbituric acid reactive substances, were monitored at regular intervals throughout storage. Results: All active coatings significantly retarded microbial growth and lipid oxidation compared to the uncoated control (p < 0.05), with effects being concentration-dependent. Nanoencapsulation was achieved with an efficiency of 74%, and all formulations consistently showed better results compared to free essential oil coatings at equivalent concentrations. Application of a chitosan coating with 1% nanoencapsulated essential oil reduced total viable count by 1.5 log CFU/g and lactic acid bacteria by 0.7 log CFU/g, with the most pronounced effect observed for Pseudomonas spp. (1.9 log CFU/g reduction). In the same sample, MDA content remained below the threshold level until the end of storage. Additionally, sensory analysis indicated that the use of nanoparticles significantly improved the overall acceptability of the coated beef. Conclusions: These findings confirm that chitosan–basil nanoparticle coatings represent a promising natural alternative to conventional preservatives for improving microbiological safety and extending the shelf life of fresh beef.

This study explores the effectiveness of electrocoagulation (EC) for removing toxic hexavalent chromium (Cr(VI)) from industrial wastewater using iron and aluminum electrodes in both batch and continuous modes. Iron electrodes demonstrated superior performance, achieving up to 99.8% Cr(VI) removal in batch mode at an optimal current density of 5 mA/cm2, while continuous operation at 50 L/h achieved comparable removal after 30 minutes, with slightly lower efficiency due to reduced retention time. The lowest specific energy consumption (2.82 kWh/kg Cr(VI)) was also recorded under these optimal conditions, highlighting economic feasibility. Fourier-transform infrared (FTIR) analysis of the sludge confirmed the reduction of Cr(VI) to the less toxic Cr(III), primarily in the form of Cr(OH)3. Characteristic peaks indicate Cr-O vibrations in chromium hydroxide, while the presence of hydroxyl (-OH) groups confirms the formation of iron hydroxide complexes that facilitate Cr(VI) adsorption and precipitation. Additional spectral features suggest the presence of iron oxides, further supporting the electrocoagulation mechanism involving the generation of coagulant species in situ. Overall, the results affirm EC as a highly efficient and cost-effective treatment method, particularly suitable for large-scale applications.

Cefazolin sorption on oxidized cellulose was performed with the aim of obtaining biologically active fibers which, as drug carriers, have a possibility of prolonged release and  local application. Oxidized cellulose with 0.555, 1.464 and 2.276 mmolg-1 COOH group was obtained by selective oxidation with a mixture of HNO3-H3PO4-NaNO2. Antibiotic water solution (c=3,4∙10-3 molL-1, t=20±1 °C)  and physiological solution were used for bonding and desorption, respectively. Maximum amount of the bound drug (0,0337 mmolg-1) was obtained during the sorption on the oxicellulose with 2,276 mmolg-1 COOH  and the maximum amount of the released drug was 0,0091 mmolg-1. Drugs sorption on the oxidized cellulose is accomplished through hydrophobic interactions. Disc diffusion test was used for determination of antimicrobial activity Staphylococcus aureus,  Bacillus subtilis and Escherichia coli.

Biologically active fibers as drug carriers have improved characteristics in comparison with conventional medical therapies. Cellulose as a hydrophilic and biocompatible, nontoxic and eco-friendly material, makes a good polymer matrix for obtaining biologically active fibers. Loading drugs on the fiber carrier is accomplished through hydrophobic interactions, which is a prevailing mechanism of drug bonding. These interactions can be achieved by hydrophobic parts of the drug and the fiber carrier or by hydrophobic drugs themselves bonded on the fiber. In this paper, oxidized cellulose (OC) with 0.547, 1.163 and 2.199 mmol/g COOH is produced by using selective oxidation of a cellulose-based bandage. Oxidation has been carried out in mixture of HNO3/H3PO4 2:1 and 1.43 % NaNO2 for 5, 10 and 20 h at 25 ± 1 °C. The OC sample with 2.199 mmol/g COOH showed the lowest sorption capacity as well as weak mechanical properties, so that the sorption experiments were not further pursued. The other two samples of oxidized cellulose with 0.547 and 1.163 mmol/g COOH have been used for chemical bonding of an analgesic, diclofenac, a derivative of potassium salt. Diclofenac in its structure contains two benzene rings which are linked via a secondary amine. The analgesic also contains a carboxyl group, as well as 2 chlorine atoms. As a result of the presence of these functional groups and structures, diclofenac can build multiple chemical bonds with an oxidized cellulose bandage. The chemical bonding of the drug has been performed using three analgesic solutions with concentrations of c = 2.5∙10-3, 3.4∙10-3 and 5.1∙10-3 mol/L, at the temperature of 26 ± 1 oC while desorption was performed in physiological saline solution. The amounts of bonded and released antibiotic were determined by UV-VIS spectroscopy at the wavelength of λmax=276 nm. The maximum amount of bonded drug (0.814 mmol/g OC) has been obtained by sorption from the solution of concentration c=5.1∙10-3, while the highest amount of desorbed diclofenac was 0.063 mmol/g OC. The sorption kinetics has been succesfully described by the pseudo-second order model. It was established that the drug bonding was achieved by hydrogen bonds of the drug functional groups with the oxidised cellulose bandage. Low diclofenac relase from the oxsidiesed cellulose (12.5 % in 24 h) is a consequence of formation of multiple bond as well as drug aggregates on fiber surfaces.

Natural biodegradable polymers such as chitosan are gaining increasing importance due to their favorable mechanical properties. Conversely, their limited antimicrobial and antioxidant activity requires enhancement with bioactive components. This study investigated the effect of Teucrium montanum L. hydrolate on the functional properties of chitosan films. The hydrolate was obtained as a by-product of hydrodistillation, and films were prepared with 0.6% (CH-TMh1), 0.8% (CH-TMh2), and 1.2% (CH-TMh3) hydrolate, along with a control film without hydrolate (CH). Hydrolate-enriched films exhibited greater thickness and elongation at break, with the highest values observed in CH-TMh3. The addition of hydrolate reduced moisture content (from 30.09% in CH to 12.25% in CH-TMh3), solubility, and swelling degree. Antioxidant activity increased significantly, with CH-TMh2 showing the highest free radical scavenging activity (92.9%) and total polyphenol content (38.78 mg GAE/g). Films containing hydrolate also displayed pronounced antimicrobial activity, with the largest inhibition zones against S. aureus ATCC 25923 (16.33 mm). Moderate activity was observed against B. subtilis, while there was no activity against C. albicans ATCC 2091. These results confirm that chitosan films enriched with T. montanum L. hydrolate possess improved mechanical, antioxidant, and antimicrobial properties, making them promising for potential application in the packaging of specific food products.