Synthetic approach, regio- and stereochemical characterisation and differentiation of new potential antioxidant C- and O- arylglycosides

Two series of C- and O-arylglycosides with potential antioxidant properties have been synthesized, characterized and structurally differentiated. Reinvestigation of a synthetic approach has provided better insight into the products obtained and their chemical structures. Regio- and stereochemical characterization and differentiation of each compound have been carried out in solution, in the crystal, and in the gas phase. A comparison between the data obtained in solution and the crystal structures suggests closely related features in the two states. Mass spectrometry proved very effective for characterization of and differentiation between C- and O-isomers, as well as positional isomers. Unimolecular reactions occurring in the gas phase are specific to the chemical structures, and ion abundances can be related to their stabilities. This study has allowed the evaluation of the influences of the different linkages between the two moieties and the positions of the substituents on the chemical properties of the compounds. The C-isomers show antioxidant capability, as peroxyl radical scavengers, and inhibit lipid peroxidation. © Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.