Monitoring and preparation of neoagaro- and agaro-oligosaccharide products by high performance anion exchange chromatography systems

A series of neoagaro-oligosaccharides (NAOS) were prepared by β-agarase digestion and agaro-oligosaccharides (AOS) by HCl hydrolysis from agarose with defined quantity and degree of polymerization (DP). Chain-length distribution in the crude product mixtures were monitored by two high performance anion exchange chromatography systems coupled with a pulsed amperometric detector. Method 1 utilized two separation columns: a CarboPac™ PA1 and a CarboPac™ PA100 connected in series and method 2 used the PA100 alone. Method 1 resolved the product in size ranges consisting of DP 1-46 for NAOS and DP 1-32 for AOS. Method 2 clearly resolved saccharide product sizes within DP 26. The optimized system utilizing a semi-preparative CarboPac™ PA100 column was connected with a fraction collector to isolate and quantify individually separated products. This study established systems for the preparation and qualitative and quantitative measurements as well as for the isolation of various sizes of oligomers generated from agarose.