Eco-Friendly Extraction of Sinapine From Residues of Mustard Production

In this study, our efforts were focused on the optimization of phenolic compounds—mainly sinapine—extraction from residues of industrial mustard production. A preliminary work was conducted to discuss the way data from Folin-Ciocalteu analytical method are reported and exploited in the literature, and to determine whether methanol can be replaced by ethanol as extracting solvent. As this first question had found a positive answer, an optimization of the extraction process on crude and pretreated industrial residue was achieved using a Response Surface Methodology (RSM). Optimal conditions obtained through this Design of Experiments (DoE) allowed the extraction of more than 10 mg/g of defatted and dried matter (aka DDM) of phenolics from defatted and dried matter, and 13 mg/g DDM of phenolics from non-pretreated matter (results expressed as equivalent of DDM)

Direct structural observation of ultrafast photoisomerization dynamics in sinapate esters

Sinapate esters have been extensively studied for their potential application in ‘nature-inspired’ photoprotection. There is general consensus that the relaxation mechanism of sinapate esters following photoexcitation with ultraviolet radiation is mediated by geometric isomerization. This has been largely inferred through indirect studies involving transient electronic absorption spectroscopy in conjunction with steady-state spectroscopies. However, to-date, there is no direct experimental evidence tracking the formation of the photoisomer in real-time. Using transient vibrational absorption spectroscopy, we report on the direct structural changes that occur upon photoexcitation, resulting in the photoisomer formation. Our mechanistic analysis predicts that, from the photoprepared ππ* state, internal conversion takes place through a conical intersection (CI) near the geometry of the initial isomer. Our calculations suggest that different CI topographies at relevant points on the seam of intersection may influence the isomerization yield. Altogether, we provide compelling evidence suggesting that a sinapate ester’s geometric isomerization can be a more complex dynamical process than originally thought

Renewable polymers derived from ferulic acid and biobased diols via ADMET

International audienceRenewable α,ω-diene monomers have been prepared from ferulic acid, biosourced diols (isosorbide and butanediol) and bromo-alkenes using a chemo-enzymatic synthetic pathway then studied as monomers in ADMET polymerization. All monomers and polymers have been thoroughly characterized using NMR, GPC, DSC and TGA. ADMET polymerization was optimized with regard to catalyst loading (Hoveyda–Grubbs II), reaction medium (in mass vs. in solvent), and temperature, which led to polymers with molecular weight up to 25 kDa. Thermal analysis of these new poly(ester-alkenamer)s showed excellent thermal stabilities (283–370 °C) and tunable Tg depending on the nature of the biobased diol and the chain length of the alkene in the α,ω-diene monomer

Biobased polymers for cosmetic formulations: an alternative to silicones

Participation au concours "Etonnants Découvreurs"International audienc

(S)-γ-hydroxymethyl-α,β-butenolide (aka HBO), a Valuable Chiral Synthon: Syntheses, Reactivity and Applications

International audienceChirality is greatly sought for pharmaceutical compounds or fragrance and flavors. (S) -γ-hydroxymethyl-α,β-butenolide, aka HBO, is a chiral (5H)-furanone providing a polarized double bond, a lactone ring and a primary alcohol as playground for synthetic chemists. This molecule has been used for forty years in a wide range of synthetic pathways to natural and/or bioactive molecules. Its own synthesis, always from biosourced product, has also significantly evolved and could be now achieved both at large scale and by applying Green Chemistryprinciples. This review will explore the syntheses, the reactivity and the uses of HBO