Protoanemonin

Biomass‐derived 5‐hydroxymethyl furfural (5‐HMF) is a promising starting substrate for producing two high value‐added products 2,5‐diformylfuran (DFF) and 2,5‐furandicarboxylic acid (FDCA). DFF, which is produced by selectively oxidizing the hydroxymethyl group of 5‐HMF to an aldehyde group, has many applications in pharmaceuticals, macrocyclic ligands and fluorescent materials. Oxidizing both aldehyde and hydroxymethyl groups of 5‐HMF leads to FDCA, which is an important monomer in the production of a bioplastic polyethylene furanoate polymer. Electrochemical conversion of 5‐HMF is a potential route for sustainable chemical production of DFF and FDCA. In fact, using 2,2,6,6‐tetramethyl‐ piperidine‐1‐oxyl (TEMPO) as a redox mediator leads to a highly efficient and selective electro‐oxidation of 5‐HMF into FDCA in a basic buffer solution. In this report, the direct and TEMPO‐mediated electro‐oxidation of 5‐HMF was investigated in various organic and hydro‐organic media at room temperature. Direct electro‐oxidation leads to a low selective conversion of 5‐HMF to DFF (10 % of yield) and the formation of unwanted products such as formic acid and protoanemonin (90 % and 37 % of yield respectively) in acetonitrile. Electrocatalytic 5‐HMF conversion in the presence of TEMPO as a redox mediator achieved a near‐quantitative yield of DFF in acetonitrile and γ‐valerolactone. Importantly, we demonstrate the role of water in the conversion of aldehydes to carboxylic acids.

Lately, green chem. has pushed researchers to investigate alternative solvents for the recovery of phenolic compounds (PC).Therefore, the optimization of PC extraction from Clematis flammula L. leaves (CFL) using ultrasound-assisted deep eutectic solvents (UAE-DES) was investigated.Addnl., phytochem. screening, biol. activity, and characterization of the bioactive mols. using gas chromatog. coupled with mass spectrometry (GC-MS) were performed.Choline chloride-acetic acid (ChCl-Acet) was explored as a potential extractant of TPC (110 ± 5.98 mgGAE/Gdw) and the optimal extraction conditions were as follows: 18.2% of water, 49.4 °C, and 40 min of extraction time.Also, the in vitro antioxidant assays revealed that CFL extract was a potent antioxidant agent with a high inhibition compared to the control with 97.23 ± 1.72% and 94 ± 4.21% inhibition for ABTS and DPPH, resp.CFL extract showed antimicrobial effects against fungus and two bacterial strains, namely Candida albicans (CA), Methicillin-resistant staphylococcus aureus (MRSA), and Pseudomonas aeruginosa (PA), resp., with a minimal inhibitor concentration (MIC) of 390 μg/mL.For the first time, GC-MS was used to assess the characterization and quantification of phenolic profiles.Protoanemonin (63.94%), phenol (8.76%), decamethyl (7.00%), linalool (5.47%), salicylic acid (4.66%), dodecamethyl (4.41%), and n-dexadecanoic acid (4.22%) were the major compounds identified.The obtained results highlight the effectiveness of choline chloride-based DES as an alternative extraction solvent for phenolic compounds for industrial and pharmaceutical applications.