Optimization of monosaccharide determination using anthranilic acid and 1-phenyl-3-methyl-5-pyrazolone for gastropod analysis

The protein-linked glycomes and, thereby, the range of individual monosaccharides of invertebrates differ from those of mammals due to a number of special modifications; therefore, it is necessary to adapt methods for monosaccharide analysis in order to cover these. We optimized the labeling procedure for anthranilic acid (AA) and 1-phenyl-3-methyl-5-pyrazolone (PMP) and the subsequent separation of the labeled monosaccharides on high-performance liquid chromatography (HPLC), with the result that we were able to identify 26 different monosaccharides. The detection limit for anthranilic acid derivatives obtained was 65 fmol, and a reliable quantification of samples was possible up to 200 nmol under the tested conditions. PMP derivatives showed a significantly higher detection limit but allow quantification of larger sample amounts. Applying these methods on snails, their impressive set of monosaccharide constituents, including methylated sugars, was shown.