Objective: Iris species are widely used in pharmaceutical and cosmetic applications owing to their high content of bioactive compounds with anti-inflammatory and antimicrobial properties. This study aimed to investigate the potential antibacterial effect of crude extracts (aqueous, 50% and 80% ethanol) of three Iris species ( I. pumila , while I. reichenbachii and I. illyrica are endemic) from Bosnia and Herzegovina against the multiresistant bacterial strain methicillin-resistant Staphylococcus aureus subsp. aureus ATCC 33591 (MRSA strain). Materials and Methods: The antimicrobial compounds in the crude extracts were identified using High-performance liquid chromatography (HPLC), and their effects on the MRSA strain were tested using agar well diffusion and broth microdilution method. The binding affinities were analysed using molecular docking simulations. Results: We identified bioactive targeted compounds in these extracts, mainly flavonoids named isorhamnetin, hesperidin, quercetin, fisetin, genistein, and kaempferol. Antibacterial assays showed that extracts of all three Iris species inhibited MRSA. The binding affinity analysis showed that isorhamnetin and hesperidin had the highest affinity scores, stronger (isorhamnetin) or the same (hesperidin) as the positive control ceftobiprole. Conclusion: This in vitro and in silico study showed that Iris species represent a valuable source of bioactive compounds that can be used against multidrug-resistant strains such as MRSA. The potential use of these agents in multiple drugs is warranted, and further evaluation for human application is needed.

Solvent and substitution effects on the UV/Vis spectroscopic and fluorescence behaviour of seven synthesized 3-substituted 4-hydroxycoumarin derivatives were tested. The tested compounds were dissolved in ethyl acetate, acetonitrile, and dimethyl sulfoxide. Absorption and emission spectra were recorded in the range of 200–800 nm. All tested 4-hydroxycoumarin derivatives showed good absorption in a wide range of 200–550 nm, depending on the properties of the substituents on the benzene ring of the cinnamoyl moiety and the type of solvent. In comparison to the unsubstituted analogue, compounds with an electron-donating group exhibited bathochromically shifted UV/Vis absorption and emission spectra. The highest fluorescence quantum yield was observed for compounds with dimethylamino and acetamido groups as substituents at the benzene ring. Considering that both substitution and solvent affect the absorption and emission spectra of the tested compounds, it can be concluded that judiciously selecting these parameters can improve their absorption and fluorescence properties, making them suitable for various analytical uses.

Skin sensitization is a crucial endpoint in the safety assessment of chemicals, with the Direct Peptide Reactivity Assay (DPRA) emerging as a valuable in chemico method for evaluating a substance's sensitization potential. This review delves into the principles, applicability, and limitations of the DPRA within the context of the Adverse Outcome Pathway (AOP) framework for skin sensitization. We examine the DPRA'srole in addressing the molecular initiating event of skin sensitization, its integration into Integrated Approaches to Testing and Assessment (IATA), and its performance in predicting sensitizers. The review also highlights the challenges in testing certain categories of chemicals and the importance of considering the DPRA's results alongside other complementary methods. By providing a comprehensive overview of the DPRA, this review aims to inform researchers, regulators, and clinicians about its utility and limitations in the context of skin sensitization testing.

The main MoR discussion led to further suggestions on KE terminology, including ensuring coherence to directionality in terms of the KE descriptions (e.g., specifying increase, decrease, altered, no direction, etc.) and clarifying differences in ROS and reactive oxygen and nitrogen species (RONS), and enzymatic and non-enzymatic events. The consortium highlighted the importance of the role of ROS as a KE and an associative event in the AOP framework. Additionally, participants highlighted modification to macromolecules from the resultant RONS generation (e.g., lipid peroxidation) as a relevant endpoint to include in the KE. The possibility of grouping ROS-related KEs in the AOP framework needs to be discussed further.