Aurones are minor flavonoids that possess a wide variety of bioactivity, including antioxidant, anticancer, and enzyme inhibitory activity. L-proline-based natural deep eutectic solvents (NaDES) were synthesized and applied as solvents and catalysts for the Knoevenagel condensation reaction between benzofuranone and substituted benzaldehydes to produce aurones in high yields and purity. The reaction between benzofuranone and vanillin served as the model reaction. After screening three NaDESs, and testing microwave, as well as ultrasound as energy sources, we concluded that the optimum results are obtained using L-proline/glycerol 1:2 as catalyst and solvent and ultrasound irradiation. The scope of the reaction was evaluated using a variety of benzaldehydes, and the corresponding aurones were obtained in moderate to satisfactory yields (57–89%) and high purity. An important additional feature of the described methodology is the recyclability and reusability of the NaDES, which was recycled and effectively reused after 6 cycles.

Biocompatible Ionic Liquids (Bio-ILs) are a new class of ILs that are task-specifically designed to derive from naturally occurring compounds and/or derivatives thereof, as well as molecules well known for their biocompatibility (e.g., active pharmaceutical ingredients or non-toxic bioactive compounds) in terms of sustainability and biocompatibility. Owing to their remarkable physicochemical properties that can be tailor made to comply with the requirements of each application, Bio-ILs have emerged as novel, efficient and green technology, appropriate for a vast variety of scientific fields. Herein, this review describes the state-of-the-art scientific research regarding the synthesis, characterization and applications of Bio-ILs reported in the literature for the period between 2020 and 2022.

Copper-contained products that are widely employed yearly in viticulture for vine disease management, lead to Cu accumulation in topsoil creating an increased risk for land workers and for leaching and/or uptake of Cu by plants, especially in acidic soils where Cu mobility is higher. In this study, the impact of two biochar types on Cu distribution and redistribution in fractions was evaluated in four acidic vineyard soils in relation to incubation time. The two biochars were derived from sewage sludge (SG) and olive tree prunings (OL). Soils (control) and biochar-amended soils with application rate of 20 % (w/w) were spiked with CuCl₂ (160 mg kg⁻¹) and incubated in the laboratory at ambient temperature 22 ± 5 °C. After 1, 3, 7, 15, 36, and 90 days of incubation, modified BCR sequential extraction procedure was used to determine Cu distribution in the four soil chemical phases and to examine potential Cu redistribution between these fractions both in soils and in amended soils with biochars. Results show that biochar amendment affects Cu distribution in different soil fractions. In SG treatment, from the 1st and up to 36th incubation day, both exchangeable and reducible Cu fractions decreased, while oxidizable Cu increased, in relation to control soils. At 90th incubation day, a redistribution of Cu was observed, mainly from the oxidizable to the residual fraction. In OL treatment, during the first 36 incubation days exchangeable and oxidizable Cu slightly increased, while reducible Cu decreased. At the 90th incubation day the higher percentage of Cu was extracted from the residual fraction, but exchangeable Cu was present in remarkable quantities in the three of the four studies soils. SG application in the studied soils highly restricted the availability of added Cu promoting Cu-stable forms thus reducing the environmental risk while OL did not substantially reduce Cu available fraction over the experimental incubation period. Fourier transformation infrared analysis (FTIR) provided convincing explanations for the different behavior of the two biochar types.

Flavanones and their biochemical precursors, chalcones, are naturally occurring compounds and consist of privileged scaffolds used in drug discovery due to their wide range of biological activities. In this work, two novel flavanones (3 and 4), the arylidene flavanone 5, and the chalcone 6, displaying structural analogies with butylated hydroxytoluene (BHT), were synthesized via an aldol reaction. According to the antioxidant activity studies of the synthesized flavanones, the arylidene flavanone 5 was the most potent antioxidant (70.8% interaction with DPPH radical and 77.4% inhibition of lipid peroxidation). In addition, the ability of the synthesized compounds to bind with ctDNA was measured via UV-spectroscopy, revealing that chalcone 6 has the strongest interaction with DNA (K_b = 5.0 $\times$ 10⁻³ M⁻¹), while molecular docking was exploited to simulate the compound-DNA complexes. In an effort to explore the conformational features of the novel synthetic flavanones (3 and 4), arylidene flavanone 5, and chalcone 6, theoretical calculations were applied and the calculation of their physicochemical properties was also performed.

Click chemistry, and particularly the Cu-catalyzed Azide Alkyne Cycloaddition (CuAAC) reaction has gained increased attention in recent years as an invaluable tool for synthesizing pharmaceutical active organic compounds. In this study, quinolinones and triazoles, two bioactive heterocyclic moieties amenable to various substitutions, were employed to design and synthesize novel quinolinone–triazole hybrid molecules via the CuAAC click reaction under microwave irradiation. The synthesized hybrid molecules and their alkyne precursors were structurally characterized and evaluated for their antioxidant capacity, lipoxygenase (LOX) inhibitory activity, cell viability using HaCaT epithelial cells, and cytotoxicity against two cancer lines. The results indicated that, among the precursors, alkyne 4c exhibits the best combined antioxidant and anti-inflammatory activity (100% lipid peroxidation inhibition, IC₅₀ = 22.5 μM for LOX inhibition); among the hybrid molecules, compound 5a was the most potent (98.0% lipid peroxidation inhibition, IC₅₀ = 10.0 μM for LOX inhibition). Regarding the assessment of HaCaT cell viability, all studied compounds showed encouraging results, with cell viability rates between 61.5% and 100%. Moreover, based on the results of the cytotoxicity against cancer lines A549 and A375, it emerged that the tested compounds exhibited moderate–low or no cytotoxicity. These results highlight the potential of quinolinone–triazole hybrids as valuable candidates in drug discovery.

Medicinal and aromatic plants continue to attract attention as rich sources of natural bioactive compounds with potential health benefits. Among them, Greek mountain tea (Sideritis scardica) is widely recognized for its high content of phytochemicals, which have been associated with various biological activities. In this study, Natural Deep Eutectic Solvents (NADESs) were investigated as a sustainable and efficient alternative to conventional solvents for the extraction of such compounds, aiming to the development of a more efficient extraction process. Six task-specific designed NADESs were prepared and evaluated for their extraction efficiency, based on the Total Phenolic Content (TPC) and Total Flavonoid Content (TFC) of the extract. The most promising NADES, comprising betaine and 1,3-propandeiol, was selected for process optimization using a Box–Behnken design and key extraction parameters were systematically examined to maximize TPC and TFC. The extract obtained under the proposed conditions (S/L = 20 mg/g, 240 min, 40% water as cosolvent) exhibited a TPC and TFC value of 49.2 mg_GAE/g and 45.9 mg_CAE/g, respectively, approximately two times higher than the values of a hydroethanolic extract, obtained under the same conditions (TPC = 26.6 mg_GAE/g, TF = 19.9 mg_CAE/g). The optimum extract was further analyzed using HPLC-DAD to determine its phytochemical profile and was compared with the conventional hydroethanolic extract, revealing the role of the selected media on the extracted compounds.