198202-14-1Relevant articles and documents
Pseudosugars, 40: Synthesis of ether- and imino-linked octyl N-acetyl- 5a'-carba-β-lactosaminides and -isolactosaminides: Acceptor substrates for α-(1→3/4)-fucosyltransferase, and enzymatic synthesis of 5a'- carbatrisaccharides
Ogawa, Seiichiro,Matsunaga, Naoki,Li, Hong,Palcic, Monica M.
, p. 631 - 642 (2007/10/03)
Synthesis of ether-linked octyl 5a'-carba-β-lactosaminide 3 and - isolactosaminide 5 was carried out in seven steps, starting from the coupling products of 1,2-anhydro-5a-carba-β-D-mannopyranose derivative 7, and the oxide anions generated from the octyl N-acetyl-β-D-glucosaminide derivatives 13 and 16, respectively, under basic conditions. The 5a-carba-α-D- mannopyranose residues of the coupling products 17 and 26 were transformed into the β-D-gluco configuration through epimerization of the respective 2'- oxo derivatives 19 and 28, and selective reduction, and then into the β-D- galacto configuration by direct nucleophilic substitution of their 4',6'- dimesylates 23 and 31 with an acetate ion. Biological assay has shown that 3 is an acceptor substrate for human-milk α-(1→3/4)-fucosyltransferase and, interestingly, 5 is not. In addition, the imino-linked congeners 4 and 6 have been synthesized by coupling of the 4-amino-4-deoxy- and 3-amino-3-deoxy derivatives 37 and 41 of octyl N-acetyl-β-D-glucosaminide, and the carba- sugar epoxide 8, respectively, and subsequent deprotection. Compound 4 is a substrate while 6 is neither a substrate nor an inhibitor for fucosyltransferase. Small-scale enzymatic synthesis was carried out by treatment of 3 and 4 with GDP-fucose and milk fucosyltransferase, which resulted in conversion into the corresponding trisaccharides 47 and 48, respectively.
