L-Proline-Based Natural Deep Eutectic Solvents as Efficient Solvents and Catalysts for the Ultrasound-Assisted Synthesis of Aurones via Knoevenagel Condensation

Comparison of green solvents for the revalorization of orange by-products: Carotenoid extraction and in vitro antioxidant activity

Orange peels contain a considerable number of bioactive compounds such as carotenoids, that can be used as ingredients in high-value products. The aim of this study was to compare orange peel extracts obtained with different green solvents (vegetable oils, fatty acids, and deep eutectic solvents (DES)). In addition, the chemical characterization of a new hydrophobic DES formed by octanoic acid and l-proline (C8:Pro) was performed. The extracts were compared in terms of carotenoid extraction, antioxidant activity by three methods, color, and environmental impact. The results confirmed that the mixture of C8:Pro is a DES and showed the highest carotenoid extraction (46.01 µg/g) compared to hexane (39.28 µg/g). The antioxidant activity was also the highest in C8:Pro (2438.8 µM TE/mL). Finally, two assessment models were used to evaluate the greenness and sustainability of the proposed extractions. These results demonstrated the potential use of orange peels in the circular economy and industry.

Discovery of anti-inflammatory natural flavonoids: Diverse scaffolds and promising leads for drug discovery

Natural products have been utilized for medicinal purposes for millennia, endowing them with a rich source of chemical scaffolds and pharmacological leads for drug discovery. Among the vast array of natural products, flavonoids represent a prominent class, renowned for their diverse biological activities and promising therapeutic advantages. Notably, their anti-inflammatory properties have positioned them as promising lead compounds for developing novel drugs combating various inflammatory diseases. This review presents a comprehensive overview of flavonoids, highlighting their manifold anti-inflammatory activities and elucidating the underlying pathways in mediating inflammation. Furthermore, this review encompasses systematical classification of flavonoids, related anti-inflammatory targets, involved in vitro and in vivo test models, and detailed statistical analysis. We hope this review will provide researchers engaged in active natural products and anti-inflammatory drug discovery with practical information and potential leads.

Synthesis of 5-arylidenerhodanines in L-proline-based deep eutectic solvent

Rhodanines and their derivatives are known to have many pharmacological activities that can be modulated through different functionalization sites. One of the most studied modification in those scaffolds is the introduction of a benzylidene moiety on C5 via a Knoevenagel reaction. Here, a facile synthesis of 5-arylidenerhodanines via a Knoevenagel reaction in an ʟ-proline-based deep eutectic solvent (DES) is reported. This method is fast (1 h at 60 °C), easy, catalyst-free and sustainable as no classical organic solvents were used. The expected compounds are recovered by a simple filtration after hydrolysis and no purification is required. Those derivatives were studied for their antioxidant activities and the results are consistent with those reported in the literature indicating that phenolic compounds are the more active ones.

Eco-friendly synthesis of new olanzapine derivatives and evaluation of their anticancer potential

New derivatives of the known antipsychotic drug olanzapine have been obtained as potential compounds with anticancer activity in two metabolically different breast cancer cell lines: MCF-7 and triple negative MDA-MB-231. The compounds were obtained under phase transfer catalysis (PTC) in the presence of microwave irradiation (MW) or ultrasound (")))"), evaluating the effect of solvents such as dimethylformamide, water, or choline chloride/urea (natural deep eutectic solvent, NaDES). In the best option, the compounds were obtained within 2 minutes with a yield of 57-86% in MW. Two of the obtained compounds which have a naphthalimide moiety and a pentyl (7) or hexyl chain (8) show pronounced cytotoxicity. Interestingly, neither olanzapine nor desmethylolanzapine (DOLA), which was one of the substrates for the synthesis reaction, showed any significant activity in the study.

Design, synthesis and evaluation of 5-chloro-6-methylaurone derivatives as potential anti-cancer agents

A series of novel 5-chloro-6-methylaurone derivatives (6a-p) were synthesized and characterized by various spectroscopic techniques. The synthesized compounds were tested for anticancer activity against 60-human cancer cell line panel derived from nine cancer types at NCI, Bethesda, USA. Among the synthesized compounds, six compounds (6e, 6f, 6h, 6i, 6k and 6 m) exhibited growth inhibition and cytotoxic activity against various human cancer cell lines in one-dose data. The most potent compound among the series, 6i was active against 55 out of 60 human cancer cell lines. Compound 6i showed remarkable % growth inhibition and cytotoxicity against various cancer cell lines exhibiting % GI in the range 36.05-199.03. The compound 6i was further evaluated for five dose assay and exhibited GI50 1.90 µM and 2.70 µM against melanoma and breast cancer cell lines respectively. Further evaluation of 6i for five-dose assay exhibited a diverse spectrum of anti-cancer activity towards all the 60 human cancer cell line panel with the selectivity index ratio ranging 0.854-1.42  and 0.66-1.35  for GI50 and TGI respectively. Based on one-dose and five-dose data compound 6i was further evaluated for cell apoptosis against MDA-MB-468 breast cancer cell line and was found to induce early apoptosis in cells explaining its mode of action. The in-silico studies for the synthesized compounds as LSD1 inhibitors (2H94) have shown better docking score and binding energy comparable to vafidemstat. All the compounds followed Lipinski rule of five. These findings concluded that the compound 6i could lead to the development of a promising therapeutic anticancer agent.