The appearance multi-drug resistant Mycobacterium tuberculosis (MTB) throughout the world has prompted a search for new, safer and more active agents against tuberculosis. Based on studies of the biosynthesis of mycobacterial cell wall polysaccharides, octyl 5-O-(α-D-arabinofuranosyl)-α-D-arabinofuranoside analogues were synthesized and evaluated as inhibitors for M. tuberculosis and Mycobacterium avium. A cell free assay system has been used for the evaluation of these disaccharides as substrates for mycobacterial arabinosyltransferase activity. © 2001 Elsevier Science Ltd. All rights reserved.