With the growing interest in natural and health-supporting foods, oak acorns (Quercus robur) are gaining renewed attention for their nutritional and antioxidant potential. This study explored how different processing methods affect bioactive compounds in three acorn-based products: raw acorn flour, roasted “coffee,” and washed-and-roasted “super coffee.” Extracts were obtained using methanol, acetone, and hexane to evaluate total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity via ABTS, DPPH, CUPRAC, FRAP, and TRP assays. Methanol proved to be the most effective solvent, extracting up to 66.53 mg GAE/g dw of phenolics in raw flour and 76.50 mg GAE/g dw in roasted “coffee,” reflecting a 15% increase in TPC after thermal treatment. However, the same treatment resulted in a 17% decrease in flavonoid content, from 181.5 mg RE/g dw in raw flour to 150.67 mg RE/g dw in “super coffee.” Antioxidant activity followed a similar pattern, with methanol extracts showing the highest values, up to 584 mg TE/g dw in the CUPRAC assay and 126.7 mg TE/g dw in ABTS. Safety was also assessed through the quantification of 16 priority polycyclic aromatic hydrocarbons (PAHs). The total PAH levels in the roasted “coffee” and “super coffee” samples were 222 ng/g dw and 290 ng/g dw, respectively. Importantly, PAH4 compounds, used as key safety indicators in EU regulations, were present in low concentrations, primarily as benzo[a]anthracene (34.3–39.8 ng/g), and none exceeded the maximum limits established for cocoa-based products. Benzo[a]pyrene, a major carcinogen, was not detected. The results confirm that acorns of Quercus robur, especially in their native flour form, are rich in antioxidants, naturally gluten-free, and safe when thermally processed, making them a strong candidate for use in functional foods.

Micromeria croatica (Pers.) Schott is a Balkan endemic of the Lamiaceae family, valued for its aromatic and medicinal properties, but it is threatened by its limited natural distribution. Micropropagation offers a sustainable method for securing biomass and provides material for chemical studies. In this work, we present the first LC-HRMS profiling of extracts (in methanol, ethyl acetate, and hexane) obtained from both native and micropropagated plants. A total of 29 metabolites were identified. A diverse spectrum of secondary metabolites was identified, including phenolic acids (gallic acid monohydrate, vanillic acid, trans-cinnamic acid), flavonoids (luteolin-7-O-rutinoside, diosmetin-7-O-glucoside, kaempferol-O-rutinoside, eriocitrin), and terpenoids (ursolic acid, tanshinone I, riligustilide). The analysis revealed that all compounds detected in native plants were also present in micropropagated material, demonstrating the preservation of the characteristic phytochemical profile in vitro. Moreover, several compounds, such as apigenin, apigenin-7-O-glucuronide, isomaltopaeoniflorin, and methoxylated flavones, were found exclusively in micropropagated samples, indicating that tissue culture may enhance the chemical diversity of the species. Ethyl acetate extracts showed the highest degree of overlap between native and in vitro plants, whereas methanol and hexane extracts contained a greater number of unique metabolites in micropropagated material. This first comprehensive phytochemical report on M. croatica highlights the importance of micropropagation as a sustainable strategy for conserving rare species while ensuring a reliable source of bioactive metabolites.

Propranolol, a widely used beta-blocker, inhibits the reaction of enzyme cholinesterase hydrolysis. Measurements of the hydrolysis rate differences between and inhibited reactions, allows the development of a kinetic method for its determination. Both systems, enzyme-substrate-chromogen and enzyme-substrate-chromogen-inhibitor, were characterized through biochemical kinetic parameters (KM = 0.326-0.330 mmol/L; Vmax = 40-42.99 ?mol/Lmin), inhibition type was recognized as competitive, and inhibition constant, Ki, was determined to be 22.60 ?mol/L. The detection and quantification limits were calculated as 0.004 and 0.0136 ?mol/L, respectively. Accuracy and precision of proposed methods were tested. Proposed method is characterized with good sensitivity, selectivity, simplicity and rapidity, thus it is convenient for clinical applications.

The aim of this study is to investigate the chemical composition of ethanol, acetone extracts and essential oil of the roots and aerial parts of Sanguisorba minor subsp. muricata. Flavonoids and phenolic acids were identified as the main components in the studied extracts herein. Rutin and quercetin-3-sophoroside were found to be dominant flavonoids in both extracts. Although it was observed that the determined chemical compositions of the essential oil obtained from the aerial parts and roots of the plant species were quite different from the data obtained by Headspace measurement, as expected, the essential oils obtained from the species were found to be rich in mainly monoterpene hydrocarbons and oxygenated monoterpenes. While salicylaldehyde, carvacrol and linalool were determined as the main components in the essential oil obtained from the aerial parts of the species, the main components in the essential oil obtained from the roots were observed as borneol, myrtenol and α-campholenol.

Biperiden, an antiparkinsonian anticholinergic drug, has been found to inhibit enzymatic hydrolysis of butyrylthiocholine iodide, which is catalyzed by serum cholinesterase. By measuring the difference in the basic and inhibitory hydrolysis reaction rates, in the presence of biperiden as an inhibitor, it is possible to develop a kinetic method for its determination. Both systems, enzyme-substrate-chromogen and enzyme-substrate-chromogen-inhibitor, were characterized by biochemical parameters (KM = 0.326 ? 0.330 mmol dm-3; Vmax = 40 - - 99 ?mol dm-3 min-1), while inhibition was defined as non-competitive with the constant of inhibition Ki = 6.142 ?mol dm-3. The reaction conditions have been optimized followed by determination of the calibration curve, the corresponding equation and the limits of detection and quantification yielding 3.84 and 12.80 nmol dm-3, respectively. Using the calibration chart, it is possible to determine biperiden in different samples in the concentration range of 0.035?35.940 ?mol dm-3. Influence of a number of substances, found in the sample, on the reaction rate was also examined. The optimized method was applied for determination of biperiden in pharmaceutical preparations. Accuracy of the method was tested using the standard addition method. The proposed method has good sensitivity, selectivity, it is simple and fast, and above all easily accessible, and thus applicable in biochemical and pharmaceutical laboratories.