Photoinduced electron transfer and chemical alpha-deoxygenation of D-galactono-1,4-lactone. Synthesis of 2-deoxy-D-lyxo-hexofuranosides.
Two simple procedures for the synthesis of 2-deoxy-D-lyxo-hexono-1,4-lactone are described. Reductive cleavage of a 2-O-tosyl derivative of D-galactono-1,4-lactone in the presence of sodium iodide afforded the 2-deoxy derivative. On the other hand, alpha-deoxygenation of D-galactono-1,4-lactone was easily achieved by photochemical electron transfer deoxygenation of HO-2 as the 3-(trifluoromethyl)benzoate. Methyl 2-deoxy-beta-D-lyxo-hexafuranoside ('methyl 2-deoxy-beta-D-galactofuranoside') was synthesized and tested as substrate for exo beta-D-galactofuranosidase from Penicillium fellutanum. The reaction was followed by HPAEC, showing that methyl 2-deoxy-beta-D-galactofuranoside was not hydrolyzed by incubation with the enzyme. Neither the 2-deoxy lactone, nor the 2-deoxy-beta-D-galactofuranoside acted as inhibitors of the reaction with the 4-nitrophenyl beta-D-galactofuranoside. The present and our previous results show that the hydroxyl groups at C-2, C-3 and C-6 of the galactofuranoside are essential for interaction with the exo beta-D-galactofuranosidase.
Chiocconi
Alejandro
A
CIHIDECAR, Departamento de Química Orgánica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón II, Ciudad Universitaria, 1428 Buenos Aires, Argentina.
Marino
Carla
C
Otal
Eugenio
E
de Lederkremer
Rosa M
RM
D002851:Chromatography, High Pressure Liquid; D004583:Electrons; D005690:Galactose / Q000031:analogs & derivatives* / Q000138:chemical synthesis*; D006026:Glycoside Hydrolases; D009682:Magnetic Resonance Spectroscopy; D010407:Penicillium / Q000201:enzymology; D010777:Photochemistry; D013329:Structure-Activity Relationship; D013400:Sugar Acids / Q000737:chemistry*; D001616:beta-Galactosidase / Q000037:antagonists & inhibitors
D013400:Sugar Acids; C007813:galactonolactone; C019327:2-deoxy-lyxo-hexose; D006026:Glycoside Hydrolases; C023112:exo-beta-D-galactofuranosidase; D001616:beta-Galactosidase; D005690:Galactose