Synthesis of 5-deoxy-beta-D-galactofuranosides as tools for the characterization of beta-D-galactofuranosidases.
Derivatives of 5-deoxy-beta-D-galactofuranose (5-deoxy-alpha-L-arabino-hexofuranose) have been synthesized starting from D-galacturonic acid. The synthesis of methyl 5-deoxy-alpha-L-arabino-hexofuranoside (14alpha) was achieved by an efficient strategy previously optimized, involving a photoinduced electron transfer (PET) deoxygenation. Compound 14alpha was converted into per-O-acetyl-5-deoxy-alpha,beta-L-arabino-hexofuranoside (16), an activated precursor for glycosylation reactions. The SnCl4-promoted glycosylation of 16 led to 4-nitrophenyl (19alpha), and 4-methylthiophenyl 5-deoxy-alpha-L-arabino-hexofuranosides (20alpha). The oxygenated analog 4-methylphenyl 1-thio-beta-D-galactofuranoside (23beta) was also prepared. The 5-deoxy galactofuranosides were evaluated as inhibitors or substrates of the exo-beta-D-galactofuranosidase from Penicillium fellutanum, showing that the absence of HO-5 drastically diminishes the affinity for the protein.
Bordoni
Andrea
A
CIHIDECAR-CONICET, Departamento de Química Orgánica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Pabellón II, Ciudad Universitaria, 1428 Buenos Aires, Argentina.
de Lederkremer
Rosa M
RM
Marino
Carla
C
D005697:Galactosides / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism*; D006026:Glycoside Hydrolases / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D010407:Penicillium / Q000201:enzymology*; D013379:Substrate Specificity
D005697:Galactosides; D006026:Glycoside Hydrolases; C023112:exo-beta-D-galactofuranosidase