Facile synthesis of alpha-D-Araf-(1-5)-D-Galf as a synthon for Mycobacterium arabinogalactans construction

LUCÍA, GANDOLFI-DONADÍO; CAROLA, GALLO-RODRÍGUEZ; ROSA, M. DE LEDERKREMER

Canela- Brasil

Simposio; 11th Brazilian Meeting on Organic Synthesis; 2005

Brazilian Chemical Society

INTRODUCTION Mycobacterial diseases have remerged in the last years because of the appearance of multi-drug resistant strains of Mycobacterium and the relation of tuberculosis with AIDS. Integrity of the mycobacterial cell wall is essential for viability of mycobacteria. One of the components of this unique cell wall is the arabinogalactan (AG), in which both arabinose and galactose are found in the furanose form, absent in mammals. The galactan region consists of alternating b-(1-5)- and b-(1-6)-linked D-Galf residues. The linear galactofuranose chain is branched at OH-5, with the arabinan chains a-attached.1 Thus, an a-D-Araf-(1-5)-D-Galf linkage anchors the arabinan component to the galactan structure. In our laboratory, we have already synthesized the decenyl glycosides of b-D-Galf-(1®6)-b-D-Galf-(1®5)-b-D-Galf and b-D-Galf-(1®5)-b-D-Galf-(1®6)-b-D-Galf, components of the galactan.2 In this work, we present a straightforward synthesis of a-D-Araf-(1-5)-D-Galf as synthon for the construction of arabinogalactan analogues.