C. Vogel, G. Pohlentz
Jan 1, 2000
Citations
0
Influential Citations
6
Citations
Journal
Journal of Carbohydrate Chemistry
Abstract
ABSTRACT α-D-Glucopyranosyl-(1-3)-α-D-mannopyranosyl-(1-7)-4-methylumbelliferone (Glc-Man-Muf) was synthesized as a potential fluorogenic substrate for endo-α-1,2-mannosidase. The synthesis was designed in a convergent way. The glucose donor ethyl 2,3,4,6-tetra-O-benzyl-1-thio-β-glucopyranoside and the mannose acceptor 1,2:4,6-di-O-isopropylidene-ß-D-mannopyranose were coupled in the presence of N-iodosuccinimide and trifluoromethane-sulfonic acid to yield the corresponding disaccharide derivative. After conversion into peracetylated α-D-glucopyranosyl-(1-3)-α-D-mannopyranose the disaccharide was attached to 4-methylumbelliferone using the Helferich method. After separation of the desired isomer, deacetylation yielded the title compound. Glc-Man-Muf was used as a substrate in endomannosidase assays with rat liver Golgi preparations as an enzyme source (in the presence of the α-glucosidase inhibitor deoxynojirimycin). The degradation of Glc-Man-Muf was linear with protein up to 300 μg and with time up to 2 h. Vmax and Km were determined to be 0.17 nmol/mg x h and 3.7 mM, respectively.