International audienceThe role of polyphenols as antioxidants in our daily nutrition has been extensively investigated, but information on composition of tannins from marine sources on nutrient utilisation is limited. This study will be focused on the determination of the polyphenol quantities in brown seaweeds from Brittany coast in France; the extracts were delivered from algae centre for valorisation (CEVA), and the fidelity of the method was examined intraday and interlaboratories. The seaweed's extracts are divided into three categories: Fucus Vesiculosus, Ascophyllum nodosum and Fucus Serratus. Consequently, the total polyphenol contents (TPC) of these extracts will be measured using Folin-Glombitza spectrophotometric method. Thereafter, the antioxidant properties of these polyphenols were determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging. All polyphenols extracted were tested using cyclic voltammetry (CV) in aprotic media. The CV is realised to compare the results from spectroscopic method and to electrochemically characterise the seaweed's polyphenols

The electrogeneration of diorganylsilanones from difunctional precursors Y(CH(2))(3)(Me)SiX(2) and Ph(2)SiX(2)(Y = NH(2), CF(3), CN; X = Cl, OEt, OMe), performed in the presence of hexamethyldisiloxane or hexamethylcyclotrisiloxane (D(3)) in the ionic liquids [C(5)H(5)NC(8)F(18)].NTf(2), [C(5)H(5)NC(18)H(38)].NTf(2) and Me(3)BuN.NTf(2), which reveal high solubility of oxygen and are inert toward superoxide anion, allows functionalized siloxanes to be produced selectively in good isolated yields.

A variety of unprecedented scaffolds containing a difluoroacyl moiety were obtained in moderate to good yields, with excellent diastereoselectivity, via electrochemical or photochemical activation of difluoroacyl heteroaryles with a series of olefinic substrates.