Sulfur Metabolites in Brassicales: From Daily Vegetables to Thiofunctional Chemistry

Abstract

Acting generally as bio-precursors of isothiocyanates, glucosinolates (GLs) are important thiosaccharidic secondary metabolites that occur in all plant families of the order Brassicales, namely, in our daily vegetables. All known GLs (ca. 120 characterized molecules) display a remarkable structural homogeneity invariably based on a β-d-glucopyrano unit and an O-sulfated anomeric (Z)-thiohydroximate function connected to a side chain whose constitution, depending on plant species, is the sole structural variant. Dedicated synthetic methods give access to natural GLs and to a diversified range of artificial GL analogues. In other respects, depending on the structure of the side chain, standard enzymatic conversions of GLs can in some cases raise the curtain over uncommon thiofunctional chemistry. In this respect, progoitrin and glucoraphenin have triggered original studies in the chemistry of cyclic thionocarbamates and thio-imidate N-oxides, respectively.

Keywords:

• Brassicales
• glucosinolates
• thiohydroximates
• thio-imidate N-oxides
• thionocarbamates

Acknowledgments

The authors are grateful to all coworkers involved over the past 20 years in GL and GL-inspired chemistry.