摘要:

To investigate the biological selectin-ligand interactions, four sulfated 2-O-α-L-fucopyranosyl β-D-galactopyranosides containing 2-branched fatty-alkyl residues in place of ceramide have been systematically synthesized. The target glycolipids were assayed for their ability to block the adhesion of HL-60 cells to immobilized P-, L- and E-selectin. Among them, 2-O-α-L-fucopyranosyl sulfatide, which is anchored with 2-(tetradecyl) hexadecyl residue showed significantly more potency of the blocking adhesion to P- and L-selectins.

ISSN:0732-8303    

DOI:10.1080/07328309808002905

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

1,2-Anhydroglucose6reacts smoothly and with a high degree of stereoselectivity with a variety of carboxylic and phosphoric acids resulting in the formation of the predominantly β-oriented 1-O-acyl and 1-O-phosphorylglucoses7-17. This methodology has been successfully applied in the construction of glycolipids1a,b. Ring-opening of the 1,2-anhydroglucose derivative19with benzoic acid furnished exclusively the β-aligned key intermediate20. Subsequent ICDT-assisted chemoselective α-glucosylation of20with thioethyl donor21, followed by glycosidation of kojibiosyl benzoate22with glycerol acceptor23gave the fully protected α-diglucosyl glycerol derivative25, which upon desilylation (→28), acylation (→29 or 30) and deprotection afforded the target glycolipids1a-bin high overall yield.

ISSN:0732-8303    

DOI:10.1080/07328309808002906

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Cyclodextrins are cyclic oligosaccharides consisting of six or more α-1,4-linked D-glucopyranose units, which possess primary hydroxyl groups at the C-6 positions and secondary hydroxyl groups at the C-2 and C-3 positions. Because cyclodextrins have a hydrophobic and optically active interior, they have been utilized as transporters of hydrophobic molecules and small molecular mimics of enzymes. The chemical modification of cyclodextrins has been investigated in order to improve these characteristics. Sulfonations of the primary or secondary hydroxyl groups of cyclodextrin have been applied for further functionalization of cyclodextrin, and several methods for regioselective sulfonations have been developed. Among these strategies, selective monotosylation of the C-6 hydroxyl group is done relatively easily by reaction of α or β-cyclodextrin andp-toluenesulfonyl chloride in pyridine1,2or in alkaline aqueous solution.3,4However, sulfonation of the secondary hydroxyl groups is more difficult and new sulfonation methods must be developed to provide precursors for cyclodextrin analogues such as amino and sulfide analogues. Several strategies for the sulfonation of one C-2 hydroxyl group have been reported. However, because reaction conditions can require specific sulfonation reagent,5alkaline condition,3-7strict anhydrous conditions,8,9or use of protected C-6 hydroxyl groups,10,11the methodology is not convenient to employ.

ISSN:0732-8303    

DOI:10.1080/07328309808002907

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

ISSN:0732-8303    

DOI:10.1080/07328309808002908

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

ISSN:0732-8303    

DOI:10.1080/07328309808002909

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor