Arabinoxyloglucan Oligosaccharides May Contribute to the Antiadhesive Properties of Porcine Urine after Cranberry Consumption.

Cranberry ( Vaccinium macrocarpon) juice is traditionally used for the prevention of urinary tract infections. Human urine produced after cranberry juice consumption can prevent Escherichia coli adhesion, but the antiadhesive urinary metabolites responsible have not been conclusively identified. Adult female sows were therefore fed spray-dried cranberry powder (5 g/kg/day), and urine was collected via catheter. Urine fractions were tested for antiadhesion activity using a human red blood cell (A+) anti-hemagglutination assay with uropathogenic P-fimbriated E. coli. Components were isolated from fractions of interest using Sephadex LH-20 gel filtration chromatography followed by HPLC on normal and reversed-phase sorbents with evaporative light scattering detection. Active urine fractions were found to contain a complex series of oligosaccharides but not proanthocyanidins, and a single representative arabinoxyloglucan octasaccharide was isolated in sufficient quantity and purity for full structural characterization by chemical derivatization and NMR spectroscopic methods. Analogous cranberry material contained a similar complex series of arabinoxyloglucan oligosaccharides that exhibited antiadhesion properties in preliminary testing. These results indicate that oligosaccharides structurally related to those found in cranberry may contribute to the antiadhesion properties of urine after cranberry consumption.

Structural Characterization of Cranberry Arabinoxyloglucan Oligosaccharides.

Cranberry ( Vaccinium macrocarpon) products are widely available in North American food, juice, and dietary supplement markets. The use of cranberry is popular for the prevention of urinary tract infections (UTIs) and other reported health benefits. Preliminary findings by our research group indicate that arabinoxyloglucan oligosaccharides are present in cranberry products and may contribute to the antiadhesion properties of urine produced after cranberry consumption, but relatively little is known regarding the oligosaccharide components of cranberry. This report describes the isolation from two cranberry sources and the complete structure elucidation of two arabinoxyloglucan oligosaccharides through the use of carbohydrate-specific NMR spectroscopic and chemical derivatization methods. These compounds were identified as the heptasaccharide ß-d-glucopyranosyl-(1→4)-[α-d-xylopyranosyl-(1→6)]-ß-d-glucopyranosyl-(1→4)-ß-d-glucopyranosyl-(1→4)-[α-l-arabinofuranosyl-(1→2)-α-d-xylopyranosyl-(1→6)]-ß-d-glucopyranose (1) and the octasaccharide ß-d-glucopyranosyl-(1→4)-[α-l-arabinofuranosyl-(1→2)-α-d-xylopyranosyl-(1→6)]-ß-d-glucopyranosyl-(1→4)-ß-d-glucopyranosyl-(1→4)-[α-l-arabinofuranosyl-(1→2)-α-d-xylopyranosyl-(1→6)]-ß-d-glucopyranose (2). Selected fractions and the isolated compounds were subjected to antimicrobial, cell viability, and E. coli antiadhesion assays. Results indicated that enriched fractions and purified compounds lacked antimicrobial and cytotoxic effects, supporting the potential use of such compounds for disease prevention without the risk for resistance development. Preliminary antiadhesion results indicated that mixtures of oligosaccharides exhibited greater antiadhesion properties than purified fractions or pure compounds. The potential use of cranberry oligosaccharides for the prevention of UTIs warrants continued investigations of this complex compound series.