Synthesis and antitumor activities of novel 5-deazaflavin-sialic acid conjugate molecules

6-Nitro-5-deazaflavin derivatives bearing O-(methyl 5-acetamido-4,7,8,9-tet ra-O-acetyl-3,5-dideoxy-D-glycero-alpha- and beta-D-galacto-non-2-ulopyrano sylonate)alkyl group (sialosylalkyl group) at N(3) or N(10) and 8-amino-5-d eazaflavin substituted with the sialosylalkyl group at the amino group were synthesized and their physicochemical properties as well as antitumor effe cts on KB and L1210 cells have been investigated. The configurations of the glycosides were determined by H-1 NMR and rate of hydrolysis of the glycos idic bond. It has been found that these conjugate molecules show significan t antitumor activities. Combination of an 8-amino-5-deazaflavin with the si alosylalkyl group have been found to give rise to significant increase in a ntitumor activities of the compound. Antitumor effects of 6-nitro-5-deazafl avin-sialic acid conjugate molecules were similar or rather weak in compari son with those of the 6-nitro-5-deazaflavin derivatives without sialosylalk yl group. (C) 2000 Elsevier Science Ltd. All rights reserved.