A new class of deep eutectic solvents (DES) was used in the extraction of levodopa (L-dopa) present in Mucuna cinerea, which has been termed “green” or “designer” solvents, with notable productive and economic/environmental benefits. The seeds of Mucuna cinerea were prepared and submitted to extraction with heating and agitation in a solvent mixture of DES with citric acid, urea, or glycerol. The extracts were analyzed by high performance liquid chromatography (HPLC) which confirmed the efficiency of DES in extracting L-dopa. These extractions were carried out to determine the L-dopa extracts in DES with regard to the induction of cellular response activity, demonstrating the synergy between L-dopa and DES. The DES-glycerol extract exhibited a higher proliferative activity than commercial L-dopa after 24 h of treatment. The human glandular kallikrein-1 gene (hGK3) demonstrated higher expression in the treatment with the DES-urea, while the G protein-coupled receptor kinase-6 gene (GRK6) showed higher expression for all extracts compared to commercial L-dopa, with a higher value obtained for DES glycerol, followed by DES urea extract. The DES extraction method is therefore promising and unprecedented, confirming its possible use in the replacement of expensive solvents, supporting the use of ecologically viable DES in the extractions of other plant species.

A previous study for the identification of acetylcholinesterase (AChE) inhibitors demonstrated that the hybrid between tyrosol, the 1,2,3-triazole nucleus, and the coumarin group, namely 7-({1-[2-(4-hydroxyphenyl)ethyl]-1H-1,2,3-triazol-4-yl}methoxy)-4-methyl-2H-chromen-2-one (10), has a high enzyme inhibitory activity. Here, we synthesized analogues of 10 via triazole with pharmacophoric groups represented by tyrosine, phenylalanine, tryptophan, and glycine in addition to evaluating the impact of coumarin-linked amino acids on AChE inhibition. We obtained eight triazoles, six of which are undescribed. In general, the presence of carboxylic acid decreased the inhibitory activity, while aromatic amino acids increased enzymatic inhibition compared to glycine. The derivative containing tyrosine, structurally most similar to 10, presented the lowest inhibition percentage, indicating that phenolic hydroxyl is not the preponderant factor for inhibition. Molecular docking was not enough to explain in vitro experiments. On the other hand, MlogP (logP calculated by the Moriguchi method) was related positively to enzymatic inhibition. To increase the hydrophobicity of the molecules, we tested the esterified triazole derivatives comparatively with the enzyme. The compound ethyl 2-(4-(((4-methyl-2-oxo-2H-chromen-7-yl)oxy)methyl)-1H-1,2,3-triazol-1-yl)acetate (6) presented an increment of inhibitory activity of 46.97 ± 1.75% at 100 μmol L-1. We also associated the best activity with the lowest van der Waals volume and molar mass values.

The present investigation describes the synthesis of a series of novel triazole derivatives from 4,4'-dihydroxybenzophenone along with their elastase inhibitory activity. The 1,2,3-triazoles were obtained via the copper(I)-catalyzed azide-alkyne cycloaddition reaction (CuAAC), also known as click reaction, between bis(4-(prop-2-yn-1-yloxy))benzophenone and several benzyl azides. It was found that five derivatives exhibited significant inhibitory effects, presenting half maximal inhibitory concentration (IC50) values in the range of 16.6 to 72.1 µM. The most active compound, namely bis(4-(1-(4-iodobenzyl)-1H-1,2,3-triazol-4-yl)methoxy)benzophenone (IC50 = 16.6 ± 1.9 µM), was found to bind to elastase with the inhibition constant (Ki) of 11.12 µM, thereby illustrating competitive inhibitory behavior. Further, docking investigations provided insights on the possible binding mode of the most active compound with the elastase.