Synthesis and structural characterization of the dilactone derivative of GD1a ganglioside.
Treatment of GD1a [alpha-Neu5Ac-(2----3)-beta-GalNAc-(1----4)-[alpha- Neu5Ac-(2----3)]-beta-Gal-(1----4)-beta-Glc-(1----1)-Cer] with dicyclohexylcarbodi-imide in anhydrous methyl sulfoxide affords 94-98% of GD1a-dilactone. The involvement of the carboxyl groups of the two sialic acid residues in the lactone rings was proved by ammoniolysis and reduction experiments, which gave ganglioside derivatives containing the amide of sialic acid and N-acetylneuraminulose, respectively. 1H-N.m.r. spectroscopy showed that the lactone rings involved position 2 of each galactose residue in the ester linkages.
Fronza
G
G
CNR Study Center for Natural Organic Substances, Department of Chemistry, Polytechnic of Milan, Italy.
Kirschner
G
G
Acquotti
D
D
Bassi
R
R
Tagliavacca
L
L
Sonnino
S
S
D055598:Chemical Phenomena; D002621:Chemistry; D002855:Chromatography, Thin Layer; D003124:Colorimetry; D003720:Densitometry; D005732:Gangliosides / Q000032:analysis / Q000138:chemical synthesis*; D007783:Lactones / Q000032:analysis / Q000138:chemical synthesis*; D009682:Magnetic Resonance Spectroscopy
D005732:Gangliosides; D007783:Lactones; C059248:ganglioside GD1a dilactone; C021298:ganglioside, GD1a