Structural parameters and natural occurrence of 2-deoxy-2,3-didehydro-N-glycoloylneuraminic acid

Abstract

1. 2-Deoxy-2, 3-didehydro-N-glycoloylneuraminic acid has been found to occur in porcine, bovine and equine submandibular glands as well as in the urine of pig, horse and rat. This novel, unsaturated sialic acid was isolated by gel filtration and ion-exchange chromatography. Final purification was achieved by column chromatography or by preparative thin-layer chromatography on cellulose. The structural analysis was performed by combined capillary gas-liquid chromatography/mass spectrometry. The various data were compared with those from synthetic 2-deoxy-2, 3-didehydro-N-acetylated derivative was present in the materials analyzed.

2. The inhibitory effect of 2-deoxy-2, 3-didehydro-N-glycoloylneuraminic acid on Vibrio cholerae sialidase using N-acetylneuraminyl-(alpha2->3)-lactose as substrate is slightly higher (50% inhibition at 10 mu M) when compared with 2-deoxy-2, 3-didehydro-N-acetylneuraminic acid (50% inhibition at 15 mu M).