1. Research Center GlaxoSmithKline Plc Via Fiorentina 1 53100 Siena Italy
2. Chemical Glycobiology Lab, CIC bioGUNE Basque Research Technology Alliance (BRTA) Bizkaia Technology Park 48160 Derio Spain
3. Ikerbasque Basque Foundation for Science 48013 Bilbao Bizkaia Spain
4. Department Organic Chemistry II University of the Basque Country UPV/EHU 48940 Leioa Bizkaia Spain