Natural deep eutectic solvents (NADESs) have been considered promising to replace traditional volatile and toxic organic solvents for the extraction of biologically active substances from natural sources. This work applied an efficient and ethanol-exclusion strategy for extraction of phenolic compounds from poplar type propolis using five known NADESs (lactic acid:1,2-propanediol 1:1, lactic acid:fructose 5:1, choline chloride:1,2-propanediol 1:3, choline chloride:1,2-propanediol:water 1:1:1 and betaine:malic acid:water 1:1:6). The selected NADESs' extractability was evaluated by measuring the concentrations of total phenolics and total flavones and flavonols in the propolis extracts obtained, which qualitative chemical composition was further determined in detail by gas chromatography-mass spectrometry (GC-MS) analysis. It demonstrated that the chemical profiles of NADES and 70% ethanolic propolis extracts are similar. To expand the knowledge about the role of the applied solvents in the poplar propolis extraction process, the in vitro antimicrobial, cytotoxic and genotoxic activity of both NADESs and liquid NADES extracts were evaluated. The results revealed that the use of the selected NADESs as an extraction media for phenolic compounds from poplar propolis not only delivered a good extraction yield in some cases, but generally led to the preservation of propolis extracts' biological activity and even to the enhancement of their antimicrobial effect in comparison with the hydroethanolic one. Besides, the tested NADESs except for lactic acid:fructose and betaine:malic acid:water exerted low to negligible toxicity against normal cells treated and apart from lactic acid:fructose the remaining solvents demonstrated concentration-dependent moderate to subtle genotoxicity. There is a probability that not the supramolecular structure of the NADESs, but their components, played a key role for the observed biological effects. The present study has demonstrated an alternative approach for extracting the biologically active complex from poplar type propolis using NADESs, which could be useful for further pharmaceutical and cosmeceutical applications.

Currently, 1-amidoalkyl-2-naphthol derivatives are of increasing interest due to their biological activities and further use in the preparation of other important bioactive molecules, such as aminoalkyl naphthols and oxazines. The synthesis of 1-amidoalkyl-2-naphthol moiety is usually achieved by employing one-pot multicomponent Mannich reactions. This review covers the recent reports on 1-amidoalkyl-2-naphthols’ preparation with the use of different catalysts and summarizes the available published data for the period of the last 3 years. It also puts emphasis on the structure, synthetic transformation and biological importance of this class of products.

Biologically active substances of natural origin offer a promising alternative in skin disease treatment in comparison to synthetic medications. The limiting factors for the efficient application of natural compounds, such as low water solubility and low bioavailability, can be easily overcome by the development of suitable delivery systems. In this study, the exchange with the template procedure was used for the preparation ofa spherical silver-modified mesoporous silica nanocarrier. The initial and drug-loaded formulations are fully characterized by different physico-chemical methods. The incipient wetness impregnation method used to load health-promoting agents, curcumin, and capsaicin in Ag-modified carriers separately or in combinationresulted in high loading efficiency (up to 33 wt.%). The interaction between drugs and carriers was studied by ATR-FTIR spectroscopy. The release experiments of both active substances from the developed formulations were studied in buffers with pH 5.5, and showed improved solubility. Radical scavenging activity and ferric-reducing antioxidant power assays were successfully used for the evaluation of the antiradical and antioxidant capacity of the curcumin or/and capsaicin loaded on mesoporous carriers. Formulations containing a mixture of curcumin and capsaicin were characterized bypotentiation of their antiproliferative effect against maligning cells, and it was confirmed that the system for simultaneous delivery of both drugs has lower IC₅₀ values than the free substances.The antibacterial tests showed better activity of the obtained delivery systems in comparison with the pure curcumin and capsaicin. Considering the obtained results, it can be concluded that the obtained delivery systems are promising for potential dermal treatment.

Natural deep eutectic solvents (NADES) have been developed in order to replace traditional volatile and toxic organic solvents for the extraction of biologically active substances from natural sources. Recent research has shown that NADES are able to retain and even improve the antioxidant properties of the molecules dissolved in them. The aim of the present study was to evaluate the antioxidant activity of the extracts of two medicinal plants, Plantago major and Sideritis scardica, and of propolis with 10 different NADES. The results obtained confirm that NADES extracts of medicinal plants and propolis have a good antioxidant potential, allowing obtaining natural antioxidants without the application of organic solvents. Because of the biocompatibility and low toxicity of the NADES, the opportunity to apply these extracts directly in formulations, such as cosmetics, food supplements, etc., seems promising.

Natural deep eutectic solvents (NADESs) coupled with ultrasound-assisted extraction (UAE) were evaluated as an extraction technique for phenolic compounds from Crataegus monogyna leaves and flowers. Nine well-known hydrophilic NADESs were investigated as green extraction media, and their extractability was assessed in terms of major individual compounds, total flavan-3-ols and proanthocyanidins, as well as antioxidant activity. Water and ethanol–water solutions (70% and 50%, v/v) were used as reference solvents. An HPLC method was developed and partially validated for the quantitative determination of key individual components, including chlorogenic acid, hyperoside, vitexin, vitexin-2″-O-rhamnoside, and vitexin 2″-O-(4‴-O-acetyl)-rhamnoside. The subsequent chemometric analysis of the datasets revealed that the NADES systems choline chloride:urea:water (1:1:6) and choline chloride:glucose:water (5:2:25) exhibited pronounced extraction performance for all investigated metabolites, while preserving high antioxidant activity of the extracts. Pearson correlation coefficients and corresponding p-values demonstrated strong and statistically significant relationships among the majority of the investigated parameters: solvents’ physicochemical properties, the yield of phenolic compounds, and the antioxidant activity of the hawthorn extracts. The results highlight the potential of choline chloride based NADESs containing urea or glucose as alternative solvents for the green production of hawthorn-derived ingredients for functional foods, nutraceuticals, and herbal preparations, thereby contributing to the development of scalable, application-oriented extraction technologies.

Copper-catalyzed aerobic oxidation of alcohols and aldehydes has become a key transformation for the sustainable synthesis of carbonyl compounds, combining high efficiency with the use of molecular oxygen as a benign terminal oxidant. Owing to its earth-abundance, low cost, low toxicity, and versatile redox properties, copper offers a compelling alternative to traditional noble metal catalysts and stoichiometric oxidation methods. This review highlights the evolution of copper-catalyzed aerobic oxidation of alcohols, emphasizing two distinct mechanistic regimes: nitroxyl radical-mediated systems and nitroxyl-free pathways, in which copper–ligand complexes directly promote dioxygen activation and substrate oxidation. Methods for conversion of aldehydes to carboxylic acids were also discussed. Apart from historical overview of the considered protocols, recent advances in the field were deliberated. Despite significant progress, the development of simpler, mediator-free catalytic systems based on readily available reagents remains a central challenge and a promising direction for future research.