New class of carbohydrate-based nonionic surfactants:: diblock co-oligomers of tri-O-methylated and unmodified cello-oligosaccharides

Mixtures of diblock co-oligomers of tri-O-methylated and unmodified cello-oligosaccharides have been found to be amphiphilic, as reported before. In order to clarify their accurate amphiphilic property, diblock co-oligomers of tri-O-methylated and unmodified cello-oligosaccharides with monodispersity, methyl beta-D-glucopyranosyl-( 1 -> 4)-2,3,6 tri-O-methyl-beta-D-glucopyranosyl-( 1 -> 4)-2,3,6-tri-O-methyl-beta-D-glucopyranosyl-( 1 -> 4)-2,3,6-tri-O-methylb- D-glucopyranosyl-( 1 -> 4)-2,3,6-tri-O-methyl-D- glucopyranoside (1, pentamer), methyl beta-D- glucopyranosyl-( 1 -> 4)-beta-D-glucopyranosyl(1 -> 4)- 2,3,6-tri-O-methyl-beta-D-glucopyranosyl( 1 -> 4)- 2,3,6-tri-O-methyl-beta-D-glucopyranosyl( 1 -> 4)- 2,3,6-tri-O-methyl-b-D-glucopyranosyl(1 -> 4)- 2,3,6-tri-O-methyl-D- glucopyranoside (2, hexamer), and methyl b-D- glucopyranosyl-( 1 -> 4)2,3,6-tri-O-methyl-beta-D- glucopyranosyl-( 1 -> 4)2,3,6- tri-O-methyl-D-glucopyranoside (3, trimer) were synthesized independently. These compounds had higher surface activities compared to the mixture of diblock co-oligomers of tri-O-methylated and unmodified cello-oligosaccharides and commercially available methylcellulose (MC) SM-4. This paper describes the methods of synthesis of these compounds, and the influence of amphiphilic character on their surface activity. A new class of carbohydrate-based nonionic surfactant without long alkyl chain was discovered.