Synthesis of 5-deoxy-b-D-galactofuranosides as tools for the characterization of ƒÒ-D-galactofuranosidases.

BORDONI, A; MUCHNIK DE LEDERKREMER, R; MARINO, C

BIOORGANIC & MEDICINAL CHEMISTRY.

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2010 vol. 18 p. 5339 - 5345

0968-0896

Derivatives of 5-deoxy-b-D-galactofuranose (5-deoxy-a-L-arabino-hexofuranose) have been synthesized starting from D-galacturonic acid. The synthesis of methyl 5-deoxy-a-L-arabino-hexofuranoside (14a) was achieved by an efficient strategy previously optimized, involving a photoinduced electron transfer (PET) deoxygenation. Compound 14a was converted into per-O-acetyl-5-deoxy-a,b-L-arabino-hexofuranoside (16), an activated precursor for glycosylation reactions. The SnCl4-promoted glycosylation of 16 led to 4-nitrophenyl (19a), and 4-methylthiophenyl 5-deoxy-a-L-arabino-hexofuranosides (20a). The oxygenated analog 4-methylphenyl 1-thio-b-D-galactofuranoside (23b) was also prepared. The 5-deoxy galactofuranosides were evaluated as inhibitors or substrates of the exo-b-D-galactofuranosidase from Penicillium fellutanum, showing that the absence of HO-5 drastically diminishes the affinity for the protein.b-D-galactofuranose (5-deoxy-a-L-arabino-hexofuranose) have been synthesized starting from D-galacturonic acid. The synthesis of methyl 5-deoxy-a-L-arabino-hexofuranoside (14a) was achieved by an efficient strategy previously optimized, involving a photoinduced electron transfer (PET) deoxygenation. Compound 14a was converted into per-O-acetyl-5-deoxy-a,b-L-arabino-hexofuranoside (16), an activated precursor for glycosylation reactions. The SnCl4-promoted glycosylation of 16 led to 4-nitrophenyl (19a), and 4-methylthiophenyl 5-deoxy-a-L-arabino-hexofuranosides (20a). The oxygenated analog 4-methylphenyl 1-thio-b-D-galactofuranoside (23b) was also prepared. The 5-deoxy galactofuranosides were evaluated as inhibitors or substrates of the exo-b-D-galactofuranosidase from Penicillium fellutanum, showing that the absence of HO-5 drastically diminishes the affinity for the protein.