Fig. 4.

Reaction products observed for α2,3-linked N-glycans from rhEPO under different conditions. (a) H5N4F1S1; (b) H5N4F1S2 and (c) H6N5F1S3 are the gross glycan compositions evaluated. Abbreviations indicate H (hexose); N (N-acetylgalactosamine); F (fucose); S (N-acetylneuraminic acid). Symbols indicate the monosaccharide residues mannose (green circle), galactose (yellow circle), N-acetylgalactosamine (blue square), fucose (red triangle), and N-acetylneuraminic acid (purple diamond). In case of derivatized sialic acids, an α2,3-linkage is depicted with a left angle, with lactonization indicated by L, MeNH₂ amidation by MA, and Me₂NH amidation by DA next to the sialic acid residue. Non-derivatized α2,3-sialic acids are depicted without an angle. The average and SDs for triplicate measurements are shown as bars and error bars, respectively (Supplementary Table 7)