title: A Convenient and Efficient Synthesis of SLeX Analogs.
abstract: Described is the preparation and use of tetrasaccharide 1, which enables a rapid and preparative scale synthesis of sialyl Lewis X (SLeX) analogs having 1-O- and 2-N-disubstituted glucosamine (GlcN) moieties. Such modifications should bring a dramatic change of the physical and pharmacological properties of the SLeX analogs. Therefore, tetrasaccharide 1 is a convenient intermediate for the synthesis of various SLeX analogs, since it has convertible 2-(trimethylsilyl)ethyl (SE) glycoside and the free amino group on GlcN moiety. The intermediate 1 was constructed from a glucosamine derivative by a highly efficient combined use of enzymatic galactosylation/sialylation and chemical fucosylation. Thus obtained 1 was converted into SLeX analogs by N-substitution followed by transformation of SE glycoside into other glycosides and deprotection. These synthesized analogs were found to inhibit cell adhesion of HL-60 cells to recombinant soluble human E-selectin.
authors.affiliation: Research Center, Sumitomo Pharmaceuticals, Co., Ltd., 1-98, Kasugadenaka 3-chome, Konohana-ku, Osaka 554, Japan.
authors.forename: Masaji
authors.initials: M
authors.lastname: Hayashi
authors.forename: Masashi
authors.initials: M
authors.lastname: Tanaka
authors.forename: Masanori
authors.initials: M
authors.lastname: Itoh
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Miyauchi