Fig. 6.
Cer-anchor compositions differentiating C18- and C20-sphingosine residues of renal Cers (A), HexCers (B) (mainly GalCer), and SM4s sulfatides (C) with a NS-backbone from extracts of cortex (blue), medulla (red), and papillae (green) as determined by LC-(ESI)MS2 (positive ESI). C18-sphingosine (d18:1) and C20-sphingosine (d20:1) containing SLs were detected by their transition to m/z 264 and to m/z 292, respectively. For saturated N-linked acyl chains, only the number of carbon atoms, i.e., 16, 18, 20, 22, 23, 24, and 26, is annotated, whereas for nervonic acid, the number of double bonds is indicated behind the colon (i.e., 24:1) in addition. Sulfatides were detected in positive ESI with their ISD to HexCer and subsequent transition to either m/z 264 or to m/z 292, respectively.