The glycosyl-aldonolactone approach for the synthesis of beta-D-Galf-(1-->3)-D-Manp and 3-deoxy-beta-D-xylo-hexofuranosyl-(1-->3)-D-Manp.
Carbohydr Res
; 311(4): 183-9, 1998 Oct.
Article
em En
| MEDLINE
| ID: mdl-9825521
A convenient synthesis of free beta-D-Galf-(1-->3)-D-Manp (8a) is reported. The disaccharide is present as external unit in the lipopeptidophosphoglycan (LPPG) of Trypanosoma cruzi and internally in the lipophosphoglycan (LPG) of Leishmania. Condensation of 2,5,6-tri-O-benzoyl-D-mannono-1,4-lactone (1) with 1,2,3,5,6-penta-O-benzoyl-D-galactofuranose, promoted by SnCl4, led to the beta-glycosyl-lactone, a key intermediate for disaccharide 8a, readily obtained by successive reduction of the lactone with diisoamylborane and debenzoylation. As in the LPG of Leishmania the HO-3 group of the galactofuranose is glycosylated by alpha-D-Galp, we also synthesized 3-deoxy-beta-D-xylo-hexofuranosyl-(1-->3)-D-Manp (8b) and p-nitrophenyl 3-deoxy-beta-D-xylo-hexofuranoside for studying the influence of HO-3 in the interaction with specific glycosidases. The disaccharide 8a, and its corresponding alditol, were good substrates for the beta-D-galactofuranosidase from Penicillium fellutanum, whereas the 3-deoxyglycosides were not hydrolyzed by the enzyme.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Beta-Galactosidase
/
Dissacarídeos
/
Glicosídeo Hidrolases
Idioma:
En
Revista:
Carbohydr Res
Ano de publicação:
1998
Tipo de documento:
Article
País de afiliação:
Argentina
País de publicação:
Holanda