title: Optimizing the enzymatic synthesis of beta-D-galactopyranosyl-D-xyloses for their use in the evaluation of lactase activity in vivo.
abstract: Disaccharides 2-O-, 3-O-, and 4-O-beta-D-galactopyranosyl-D-xyloses (2, 3, and 1, respectively) were obtained by beta-galactosidase-catalyzed reactions for their use in the evaluation of intestinal lactase activity in vivo. Their administration to suckling rats followed by determination of the derived D-xylose in the urine and measurement of lactase activity in intestinal homogenates showed 1 to be the most suitable disaccharide for a potential test of the deficiency of intestinal lactase. The synthesis of 1 was further studied by evaluating the effect of different variables on the yield and regioselectivity of the enzymatic galactosylation, and the purification process was optimized.
authors.affiliation: Departamento de Química Orgánica Biológica, Instituto de Química Orgánica General, CSIC, Juan de la Cierva 3, 28006 Madrid, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Hermida
authors.forename: Guillermo
authors.initials: G
authors.lastname: Corrales
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Cañada
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Aragón
authors.forename: Alfonso
authors.initials: A
authors.lastname: Fernández-Mayoralas
mesh_terms: D000375:Aging / Q000502:physiology; D000818:Animals; D004187:Disaccharides / Q000737:chemistry* / Q000378:metabolism* / Q000494:pharmacology; D005690:Galactose / Q000737:chemistry* / Q000378:metabolism*; D005696:Galactosidases / Q000378:metabolism; D007536:Isomerism; D043322:Lactase / Q000378:metabolism*; D015394:Molecular Structure; D051381:Rats; D012996:Solutions; D014994:Xylose / Q000031:analogs & derivatives* / Q000096:biosynthesis / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D004187:Disaccharides; D012996:Solutions; D014994:Xylose; D005696:Galactosidases; D043322:Lactase; D005690:Galactose