Ceramides (Cer) and Phosphoceramides

Class abbreviations

Common Name Lipid Class [LIPID MAPS] Abbreviation
Ceramides Ceramides [SP02] Cer
Ceramide-phosphates Ceramide phosphates [SP0205] CerP
Acyl Ceramides Acylceramides [SP0204] ACer
Sphingomyelins Ceramide phosphocholines (sphingomyelins) [SP0301] SM
Ethanolaminephosphorylceramides Ceramide phosphoethanolamines [SP0302] CerPE
Glycosylinositolphosphorylceramides Ceramide phosphoinositols [SP0303] GIPC
Mannosyl-inositolphosphoceramides Ceramide phosphoinositols [SP0303] MIPC
Mannosyl-diinositolphosphoceramide Ceramide phosphoinositols [SP0303] M(IP)2C

Specific rules for Ceramides (Cer) and Phosphoceramides

  • In ceramides the sphingoid backbone is annotated C-atoms:DBE;O-atoms separated by a slash from the number of C-atoms:DBE;O-atoms of the N-linked fatty acid, e.g. Cer 18:1;O2/16:0.
  • Double bond geometry is annotated in parentheses and other functional groups are preceded by the position numbers, e.g. Cer 18:1(4E);1OH,3OH/16:0. Further characterization of N-linked fatty acid is done as described for fatty acyls.
  • A fatty acid esterified to an N-linked hydroxy-fatty acyl is shown in a separate pair of parentheses xO(FA C-atoms:DBE) with x denoting the position of hydroxyl group (∆ nomenclature) in the N-linked fatty acids, e.g. Cer 18:1;O2/26:0;18O(FA 16:0).
  • Fatty acyl modification of a sphingoid base-OH is written in front of (sub)class abbreviation with integrated position number in brackets at the end of abbreviation, e.g. FA 24:1-Acer[1] 18:1;3OH/16:0.
  • Ceramide phosphates with unknown phosphate position are represented by CerP, e.g. CerP 18:1;O2/16:0.
  • Ceramide phosphates with known position of phosphate and of OH-positions are annotated by, e.g., CerP[1] 18:1(4E);3OH/18:0.
  • Ceramide phosphates with 1,3 cyclic phosphate and known OH-positions are annotated by, e.g., CerP[1,3] 18:1(4E)/18:0.
  • Consequently, in shorthand notation from Structure defined level onwards only unmodified OH-groups of the sphingoid base are annotated
  • The same applies to sphingomyelin (SM), it contains by definition the phosphocholine group, due to modification of the 1OH-group.

Hierarchical shorthand notation for examples of sphingolipids containing an amide-bound fatty acid

Species level: Sum composition, Molecular species level: Lipid species with identified SPB and N-acyl residue, Full structure level: Molecular species with constituents and functional groups including positions.
Phyla Species level1 Molecular species level Full structure level
Mammalian Cer 34:1;O2 Cer 18:1;O2/16:0 Cer 18:1(4E);1OH,3OH/16:0
Ceramide structure
Mammalian Cer 34:0;O2 Cer 18:0;O2/16:0 Cer 18:0;1OH,3OH/16:0
Mammalian ACer 58:1;O2 FA 24:1-ACer 18:1;O2/16:0 FA 24:1-ACer[1] 18:1(4E);3OH/16:0
Mammalian CerP 34:1;O2 CerP 18:1;O2/16:0 CerP[1] 18:1(4E);3OH/16:0
Mammalian SM 36:2;O22 SM 18:2;O2/18:0 SM[1] 18:2(4E,14Z);3OH/18:0
Sphingomyelin structure
Mammalian SM 44:2;O22 SM 20:1;O2/24:1 SM[1] 20:1(4E);3OH/24:1(15Z)
Mammalian Cer 62:3;O4 Cer 18:1;O2/26:0;O(FA 18:1)
Cer 18:1;O2/44:2;O2 		Cer 18:1(4E);1OH,3OH/26:0;26O(FA 18:1(9Z))
Yeast Cer 44:0;O5 Cer 18:0;3O/26:0;O2 Cer 18:0;1OH,3OH,4OH/26:0;2OH,3OH
Plant IPC 42:1;O4 IPC 18:1;O3/24:0;O IPC[1] 18:1(8E);3OH,4OH/24:0;2OH
Ceramide phosphoinositol structure
Plant HexA-IPC 42:1;O4 HexA-IPC 18:1;O3/24:0;O GlcA-IPC[1] 18:1(8E);3OH,4OH/24:0;2OH
Plant HexHexA-IPC 42:1;O4 Hex-HexA-IPC 18:1;O3/24:0;O Glc-GlcA-IPC[1] 18:1(8E);3OH,4OH/24:0;2OH
Plant HexAHexNAc-IPC 42:1;O4 HexNAc-HexA-IPC 18:1;O3/24:0;O GlcNAc-GlcA-IPC[1] 18:1(8E);3OH,4OH/24:0;2OH
Plant HexHexAHexNAc-IPC 42:1;O4 Hex-HexNAc-HexA-IPC 18:1;O3/24:0;O Glc-GlcNAc-GlcA-IPC[1] 18:1(8E);3OH,4OH/24:0;2OH
Yeast MIPC 44:0;O4 MIPC 18:0;O3/26:0;O MIPC[1] 18:0;3OH,4OH/26:0;2OH
Glyco-ceramide phosphoinositol structure
Yeast M(IP)2C 46:0;O4 M(IP)2C 20:0;O3/26:0;O M(IP)2C[1] 20:0;3OH,4OH/26:0;2OH
1 Annotation based on exact mass measurements using a high-resolution mass spectrometer.
2 Annotation using low resolution MS QQQ and a PIS m/z 184 requires the assumption of a sphingoid base with two hydroxyl groups.