Silver nanoparticles were biosynthesized using extracts from the plant Agrimonia eupatoria. After the characterization, their antioxidant activity, antimicrobial activity, genotoxicity, cytotoxicity, and hemolytic activity were investigated.

This aimed to develop a comprehensive theoretical protocol for examining substitution reaction processes. The researchers used a theoretical quantum-mechanical protocol based on the QM-ORSA approach, which estimates the kinetic parameters of thermodynamically favourable reaction pathways. This theoretical protocol was validated by experimentally investigating substitution mechanisms in two previously synthesised Pd(II) complexes: chlorido-[(3-(1-(2-hydroxypropylamino)ethylidene)chroman-2,4-dione)]palladium(II) (C1) and chlorido-[(3-(1-(2-mercaptoethylamino)-ethylidene)-chroman-2,4dione)]palladium(II) (C2), along with biologically relevant nucleophiles, namely L-cysteine (L-Cys), L-methionine (L-Met), and guanosine-5′-monophosphate (5′-GMP). Reactions were investigated under pseudo-first-order conditions, monitoring nucleophile concentration and temperature changes using stopped-flow UV-vis spectrophotometry. All reactions were conducted under physiological conditions (pH = 7.2) at 37 °C. The reactivity of the studied nucleophiles follows the order: L-Cys > L-Met > 5′-GMP, and the reaction mechanism is associative based on the activation parameters. The experimental and theoretical data showed that C2 is more reactive than C1, confirming that the complexes’ structural and electronic properties greatly affect their reactivity with selected nucleophiles. The study's findings have confirmed that the primary interaction occurs with the acid–base species L-Cys, mostly through the involvement of the partially negative sulfur atom (87.2%). On the other hand, C2 has a higher propensity for reacting with L-Cys⁻, primarily through the partially negative oxygen atom (92.6%). The implementation of this theoretical framework will significantly restrict the utilization of chemical substances, hence facilitating cost reduction and environmental protection.

In this research study, silver nitrate and an aqueous extract of the Agrimonia eupatoria L. plant were used for the synthesis of silver nanoparticles (AgNPs). The optimal conditions for this green synthesis were examined: the concentration of starting substances, pH value, and temperature. For the maximum AgNP yield, the best conditions were a 5 mM AgNO₃ concentration, 1% extract concentration, a temperature of 25 °C, pH = 6, and a 3 h reaction time.

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 and 10 mg/mL 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.