Glycoazodyes (or GADs) are a family of "naturalised" synthetic dyes, so called because they are the conjugation of common commercial azo dyes with a sugar through a "linker".[1] This principal is summarised in the scheme below.
http://onlinelibrary.wiley.com/doi/10.1002/ejoc.200600686/abstract
^ G. Bartalucci, R. Bianchini, G. Catelani, F. D’Andrea, and Lorenzo Guazzelli, Eur. J. Org. Chem. 2007, 588–595 doi:10.1002/ejoc.200600686 Roberto Bianchini*, Giorgio Catelani*, Elena frino, Jalal Isaad, Massimo Rolla. ncsu.edu/BioRessources, 2007, 2(4), 630-637. Roberto Bianchini*, Giorgio Catelani*, Riccardo Cecconi, Felicia D’Andrea, Lorenzo Guazzelli, Jalal Isaad, Massimo Rolla. European Journal of Organic Chemistry, 2008, (3), 444-454. Roberto Bianchini*, Giorgio Catelani*, Riccardo Cecconi, Felicia D’Andrea, Elena Frino, Jalal Isaad, Massimo Rolla.. Carbohydrate Research, 2008, 343(12), 2067-2074. Jalal Isaad, Massimo Rolla, Roberto Bianchini*. European Journal of Organic Chemistry, 2009, (17), 2748–2764. DOI-10.1002/ejoc.200801302. Roberto Bianchini*, Giorgio Catelani*, Jalal Isaad, Felicia D’Andrea, Massimo Rolla, Tiziano Nocentini, Filippo Bonacorsi. European Patent Application, EP08425016.6 – 2103. Déposé le 11/01/2008.