Thiodisaccharides with galactofuranose or arabinofuranose as terminal.

REPETTO, EVANGELINA; MARINO, CARLA; UHRIG, MARIA LAURA; VARELA, OSCAR

BIOORGANIC & MEDICINAL CHEMISTRY.

Elsevier

Año: 2009 vol. 17 p. 2703 - 2711

0968-0896

Thiodisaccharides having beta-D-Galf or alpha-L-Araf units as non-reducing end have been synthesized by the SnCl4- or MoO2Cl2-promoted thioglycosylation of per-O-benzoyl-D-galactofuranose (1), its 1-O-acetyl analogue 4, or per-O-acetyl-alpha-L-arabinofuranose (16) with 6-thioglucose or 6-thiogalactose derivatives.After convenient removal of the protecting groups, the free thiodisaccharides having the basic structure beta-D-Galf(1,6)-6-thio-alpha-D-Glcp-OMe (5) or beta-D-Galf(1,6)-6-thio-alpha-D-Galp-OMe (15) were obtained. The respective alpha-L-Araf analogues 18 and 20 were prepared similarly from 16. Alternatively, beta-D-Galf(1,4)-4-thio-3-deoxy-alpha-L-Xylp-OiPr was synthesized by Michael addition to a sugar enone of 1-thio-beta-D-Galf derivative, generated in situ from the glycosyl isothiourea derivative of 1. The free S-linked disaccharides were evaluated as inhibitors of the beta-galactofuranosidase from Penicillium fellutanum, being 15 and 20 the more active inhibitors against this enzyme.