1. University of Namur (UNamur); Département de Chimie, Laboratoire de Chimie Bio-Organique; rue de Bruxelles 61 5000 Namur Belgium
2. The Key Laboratory of Chemistry for Natural Products of Guizhou Province; Chinese Academy of Sciences; 202, Sha-chong South Road Guiyang 550002 P. R. China
3. Department of Chemistry and Alberta Glycomics Centre; University of Alberta, Gunning-Lemieux Chemistry Centre; 11227 Saskatchewan Drive Edmonton AB T6G 2G2 Canada