Jernej Iskra

Molecular-level interactions of naturally occurring catechol derivatives with ferrite surfaces were investigated using permanently magnetic barium hexaferrite nanoplatelets and superparamagnetic iron oxide nanoparticles. Catechol (1,2-benzenediol) and guaiacol (2-methoxyphenol) were selected as representative aromatic ligands relevant to catechol- and guaiacyl-containing natural compounds. First-principles calculations indicated facile proton transfer from the ligands to surface oxygen or hydroxyl sites and predicted strong H-bonding between the resulting surface-bound species and neighbouring surface groups. Consistent with these predictions, spectroscopic and thermal analyses together with zeta-potential measurements support a surface-complexation mechanism in which the complexes are stabilized by hydrogen bonds, also involving the ortho-phenol or methoxy group and an adjacent surface hydroxyl group. Ligand adsorption did not significantly affect the magnetic behaviour of either ferrite. Both nanoparticle systems remained chemically stable after the catechol adsorption at pH 10, while barium hexaferrite nanoplatelets were also stable under near-neutral conditions. In contrast, catechol derivatives accelerated the decomposition of barium hexaferrite nanoplatelets at pH 3. Moreover, barium hexaferrite nanoplatelets catalyzed the oxidation of catechols by molecular oxygen in aqueous dispersions. These results link proton transfer and hydrogen-bond-assisted surface complexation with the stability of ferrite nanoparticles and reactivity toward catechol ligands in aqueous environments.

The trifluoromethylthio functional group (CF3S−) has gained considerable attention in synthetic and medicinal chemistry due to its ability to enhance the pharmacokinetic profiles of functionalized compounds. This Synopsis highlights recent progress in the incorporation of the CF3S group into biomolecules and bioactive compounds, with a focus on its influence on physicochemical properties and its applications in medicinal chemistry and chemical biology.

The incorporation of fluorinated amino acid residues into peptides represents a promising strategy for improving the pharmacokinetic properties of bioactive peptides. Herein, we report the solid-phase synthesis (SPPS) of a set of ten SCF₃- or CF₃-modified neuropeptide analogs based on endomorphin-1 (EM1). EM1, a selective subnanomolar μ-opioid receptor (μOR) agonist with poor metabolic stability (t_1/2 = 6 min in human plasma), was selected as a model to evaluate the effects of SCF₃ and CF₃ functionalization on the pharmacokinetic profile of short bioactive peptides. The syntheses of eight ready-to-use SCF₃- or CF₃-containing building blocks for SPPS and their incorporation into peptides are reported. In vitro μOR binding and functional activity assays demonstrated that most fluorinated analogs retained binding affinity and potency, accompanied by increased hydrophobicity. Among the series, modification of the pharmacophoric Tyr¹ residue with l-Dmt(3-SCF₃) yielded the most favorable profile (K_i = 1.4 nM, EC₅₀ = 0.9 nM). Plasma stability studies revealed a significant increase in half-life for this ligand (72-fold relative to EM1 and 14-fold relative to EM1(Dmt¹)), and thus, further demonstrated the potential of SCF₃-containing amino acids in therapeutic peptide design.

Lignin, an underutilized by‐product of the processing of lignocellulosic biomass, represents a promising opportunity for the development of high‐value nanomaterials. Unlike cellulose and hemicellulose, which are widely used in industry, the complex and heterogeneous structure of lignin has hindered its utilization on a large scale. Recent advances in nanotechnology have enabled the transformation of lignin into functional nanomaterials with a wide range of applications. This article explores the latest developments in lignin‐based nanomaterials (NanoLGs), which is divided into lignin‐based nanomaterials (LBNMs), lignin‐derived nanomaterials, and nanohybrid LBNM materials. Each of the mentioned groups has its own attractive features and possible applications that can be competitive with traditional nanomaterials. The main advantages of NanoLGs are sustainability, biocompatibility, tunable functionality, and potential for diverse applications in environmental remediation, energy storage, biomedical devices, and advanced materials. Future research needs to focus on refining synthesis techniques, improving material performance, and integrating sustainability aspects. NanoLGs have the potential to replace fossil‐based materials and pave the way for a greener, more sustainable future.

Phenolic azobenzenes have garnered significant attention as functional materials due to their ability to undergo reversible photoisomerization and their potential for cation complexation. This review aims to provide a comprehensive overview of the recent developments in the synthesis, properties, and applications of phenolic azobenzene derivatives in cation binding and complexation. This article explores various synthetic strategies for the preparation of phenolic azobenzenes. Additionally, the mechanisms of cation complexation, including the role of the phenolic hydroxyl group and the azobenzene scaffold, are discussed, along with insights into the coordination chemistry involved. This review further examines the diverse applications of phenolic azobenzene complexes in fields such as ion sensing, catalysis, and biological and DSSC applications.

Standard operating procedure (SOP) for the characterization of Organosolv lignin from wood using nuclear magnetic resonance (NMR) spectroscopy is presented. The aim of this procedure within the Nanostructurome methods pipeline is to determine the structural composition of lignin, including the relative proportions of syringyl (S), guaiacyl (G), and p-hydroxyphenyl (H) units, as well as the distribution of interunit linkages such as β-O-4, β-β, and β-5 bonds. The extracted lignin was analyzed using 2D heteronuclear single quantum coherence (HSQC) NMR spectroscopy. This method enables precise structural elucidation of signals from aromatic and aliphatic regions. The mathematical model quantifies the abundance of aromatic units and in-terunit linkages, allowing for comparison of lignin fractions. Proper laboratory prac-tices, including chemical handling, equipment maintenance, and data management, are outlined to ensure the reliability and reproducibility of results. Health and safety measures are emphasized, particularly regarding the disposal of byproducts such as black liquor and solvent waste. The SOP serves as a valuable guideline for lignin structural analysis, facilitating its application in biorefinery processes, material devel-opment, and bioengineering.

12th Socratic Lectures symposium took place online on January 11, 2025. It featured five plenary lectures, 12 scientific sessions, a poster session and a newly introduced session called “The student zone”. As we received more than 40 papers, The Proceedings of the 12th Socratic Lectures is organized in three parts. Part I contains mainly papers from the medical fields, Part II contains mainly papers from the natural and social sciences and Part III contains standard operating procedures of a pipeline for assessment of extracellular particles and related publications. The pipeline was designed within the preparatory project Nanostructurome. Socratic lectures present an important meeting point for the participants of various projects and for the publication of scientific results, opinions, repositories, and any kind of documents that are useful in the management of the projects. But in the first place, the 12th Socratic lectures are a meeting point for scientists, artists and friends from many different fields.