Structural analysis of A_pae glycolipids. Structural signatures indicative for the identification of Fs are indicated in red font. (A) LC-ESI/MS and MS-MS analysis of the oligosaccharides derived from fraction CM65:35 of A_pae#2 glycolipids (#2) and Fs and p-Fs references. (Ai) Base peak chromatogram from LC-ESI/MS, representing the main oligosaccharides in fraction CM65:35 of A_pae#2. (Aii) Mass chromatogram of oligosaccharides with m/z 909 (indicative for Fs, p-Fs, and x₂) in the same fraction as in panel Ai shows peaks at retention time 10.1 and10.4, corresponding to Fs. (Aiii) Reference Fs m/z 909 mass chromatogram, showing the diagnostic retention time at 10.1 and10.4. (Aiv) Reference p-Fs m/z 909 mass chromatogram with retention time 9.8 and 10.2. (Av) MS-MS spectrum of the ion at m/z 909; see (Aii) retention time 10.4 minutes. (Avi) MS-MS spectrum of m/z 909 (retention time 14.0 minutes) indicating a x₂ oligosaccharide. (Avii) Reference Fs MS-MS spectrum of m/z 909 (retention time 10.4 minutes). (Aviii) Reference p-Fs MS-MS spectrum of m/z 909 (retention time 9.8 minutes). (B) Interpretation MS-MS fragmentation formulas. (C) Low-field part of the 600-MHz proton NMR spectrum shown on top of the DQF-COSY spectrum, corresponding to the H1/H2 connectivities of the signature resonances for the structures present in the A_pae#2 CM65:35 fraction. The anomeric resonances from the 2 terminal residues of the dominating globoside structure (GbO₄) have been truncated at a height corresponding to approximately 20% of the total amplitude. In the COSY spectrum, connectivities belonging to expected structures (nLc₄, P1, H-5-2, GbO₅) have been outlined by black ellipses. H1/H2 connectivities of the 3 terminal residues (GalNAcα3GalNAcβ3Galα4−) of Fs are indicated with red ellipses. Also shown by blue circles is the absence in this fraction of the 3 terminal residues of p-Fs (GalNAcβ3GalNAcβ3Galα4−). (D) Reference NMR spectra of Fs and p-Fs glycolipids isolated from chicken and human erythrocytes, respectively.