A new glycosylation method. Part 2: Study of carbohydrate elongation onto the gold nanoparticles in a colloidal phase

A new reaction for carbohydrate elongation for synthesis of oligosaccharide using gold colloidal nanoparticles (GCNPs) has been developed. The gold core in this colloidal phase synthesis was prepared by a reduction of tetrachloroauric acid with 30,31-dithia-3,6,9,12,15,18,43,46,49,52,55,58-dodecaoxa-1,60-hexacontanediol. The presented alkanethionyl oligomeric ethylene glycol worked as a stabilizer of GCNPs and as a linker in chemical elongations of carbohydrates. This colloidal phase synthesis has several advantages such as (1) remnants of reagents and glycosyl donors in each reaction could be easily removed by ultrafiltration or gel filtration column chromatography, (2) further purifications are not required, and (3) the reactions can be monitored by MALDI-TOF MS directly without any pretreatment. In fact, we have successfully synthesized lactose derivative on GCNPs and will report these results in this paper.