Synthesis of the sialyl Lewis X epitope attached to glycolipids with different core structures and their selectin-binding characteristics in a dynamic test system.

摘要: Sialyl Lewis X (sLeX)/selectin-mediated leukocyte rolling along endothelial cells has recently gained wide interest. In this paper the influence of spacer length laterally clustered neoglycolipids 1a-d on cell in a dynamic test system is investigated. The required di-O-hexadecyl glycerols with none, and three, six, or nine ethylene glycol units as groups (compounds 4a-d) could be readily obtained. synthesis 1-O-thexyldimethylsilyl-protected sLeX 24 was based sialylation 2,3,4-O-unprotected galactose derivative 11 sialyl phosphite 8 donor; afforded desired disaccharide 12, which transformed into trichloroacetimidate 14 donor. Reaction 3-O-unprotected glucosamine 18 fucosyl donor 20 21, 4-O-unprotected 23. 23 furnished tetrasaccharide good yield. Transformation 26 donor, followed by reaction 4a-d acceptor gave, after deprotection, target molecules 1a-d. For comparison, 4d also connected residue (-->31) an N-acetylglucosamine (-->34). Compounds 1c 1d hexaethylene nonaethylene spacer, respectively, were much more efficient mediating selectin-dependent than compounds 1a 1b, had no (1a), only triethylene (1b).