Unconventional methyl galactan synthesized via the thexyldimethylsilyl intermediate: preparation, characterization, and properties.
Reaction of a beta-(1 --> 4) linked galactan with TDMS chloride followed by methylation and desilylation yields methyl galactans with unconventional functionalization patterns. The products were characterized via FTIR and NMR of the intact polymer and by CE after controlled depolymerization. A TDMS-derivatized methyl galactan contains differently methylated secondary hydroxyl groups. SEC and analytical ultracentrifugation showed a consistent decrease in the molecular weight after the consecutive reaction steps. Biological studies revealed that the methyl galactans are less active in complement fixation assays as compared with a 3-O-methyl galactan-enriched polysaccharide fraction isolated from Acanthus ebracteatus.
Koschella
Andreas
A
Center of Excellence for Polysaccharide Research, Friedrich Schiller University of Jena, Humboldtstrasse 10, Jena, Germany.
Inngjerdingen
Kari
K
Paulsen
Berit S
BS
Morris
Gordon A
GA
Harding
Stephen E
SE
Heinze
Thomas
T
D003168:Complement Fixation Tests; D005685:Galactans / Q000138:chemical synthesis*; D009682:Magnetic Resonance Spectroscopy; D008756:Methylgalactosides / Q000138:chemical synthesis*; D008958:Models, Molecular; D015394:Molecular Structure; D017550:Spectroscopy, Fourier Transform Infrared; D014461:Ultracentrifugation
D005685:Galactans; D008756:Methylgalactosides