Product monitoring and quantitation of oligosaccharides composition in agar hydrolysates by precolumn labeling HPLC.

Abstract

Since the discovery of multiple bioactivities for agarobiose oligomers, a quantitative method has been in great need to monitor the agarobiose oligomers. This report demonstrates that agarobiose oligomers can be separated with high resolution in HPLC after introducing alpha-naphthylamine into compounds. Agarobiose oligomers ranged from biose to decaose were isolated by Sephadex column. HPLC analysis indicated that each oligomer could be quantified with good linearity and a low detection limit of 0.1-4mug/ml. The chromatographic profiles of agaro-oligosaccharides with different hydrolysis modes (hydrochloride, citric acid, solid acid, and hydroxyl radical degradation) showed that agarobiose could be obtained more than 57.8% using solid acid mediated hydrolysis, while hydrochloride acid could degrade agar into a series of agaro-oligosaccharides from biose to decaose. The yield of oligosaccharides was low if hydrolyzed by citric acid. The Fenton degradation can increase the speed of hydrolysis, but the product was complex.