Glycerolipids (GL)

Class abbreviations

Common Name Lipid Class Abbreviation
Monoacyl/alkylglycerides Monoradylglycerols MG
Diacyl/alkylglycerides Diradylglycerols DG
Triacyl/alkylglycerides Triradylglycerols TG
Estolides Estolides TG-EST
Sulfoquinovosylmonoacylglycerols; Glycosylmonoacylglycerols SQMG
Monogalactosylmonoacylglycerol Glycosylmonoacylglycerols MGMG
Digalactosylmonoacylglycerol Glycosylmonoacylglycerols DGMG
Sulfoquinovosyldiacylglycerols Glycosyldiacylglycerols SQDG
Monogalactosyldiacylglycerol Glycosyldiacylglycerols MGDG
Digalactosyldiacylglycerol Glycosyldiacylglycerols DGDG

Specific rules for GL with known fatty acyl/alkyl constituents (molecular species)

  • separator _: sn-position of acyl/alkyl constituents is not known. Constituents are presented in the order of increasing number of C-atoms, as are DB (DBE)-numbers for each C-atom number, e.g. TG 16:0_18:1_18:3.
  • separator /: sn-position of acyl/alkyl constituents is proven (order sn-1/sn-2/sn-3; no FA linked 0:0), e.g. TG 16:0/18:3/18:1 or DG 16:0/18:2/0:0.
  • When only one acyl chain of TG is known, it is presented in front of the sum of the remaining two acyl residues, e.g. TG 16:0_36:3.
  • When only one of the sn-positions is defined, this is indicated inside a pair of parentheses, e.g. TG 16:0_18:1(sn-2)_18:0. Other bond types than ester bonds are indicated as follows in front of the sum of C-atoms for acyl/alkyl constituents:
  • O = alkyl, e.g. TG O-52:3
  • P = proven O-alk-1-enyl-bond (acid-sensitive ether bond in “neutral plasmalogens” is not counted as a DB/DBE within the alkyl-chain), e.g. TG P-52:3 or at higher resolution TG P-16:0/18:3/18:1.
  • More than one "non"-ester bond is indicated in front of the bond type as d for di, t for tri, and e for tetra.

Hierarchical shorthand notation for examples of glycerolipids

Species level: Sum composition, Molecular species level: Lipid species with identified acyl/alkyl-residues, sn-Position level: Fatty acyl/alkyl constituents at glycerol backbone are indicated by a slash, Full structure level: Molecular species with constituents and functional groups including positions.

Bond type Species level1 Molecular species level sn-Position level Full structure level
Acyl MG 18:0 MG 18:0 MG 0:0/18:0/0:0
Alkyl MG O-18:0 MG O-18:0 MG 0:0/O-18:0/0:0
Diacyl DG 34:1 DG 16:0_18:1 DG 16:0/18:1/0:0 DG 16:0/18:1(9Z)/0:0
Acyl-alkyl DG O-34:1 DG O-16:0_18:1 DG O-16:0/18:1/0:0 DG O-16:0/18:1(9Z)/0:0
Dialkyl DG dO-32:1DG 30:12 DG O-16:0_O-16:1 DG O-16:0/O-16:1/0:0 DG O-16:0/O-16:1(9Z)/0:0
Triacyl TG 52:2 TG 16:0_18:1_18:1 TG 16:0_36:2 (only one acyl chain identified) TG 16:0/18:1/18:1 TG 16:0_18:1(sn-2)_18:1 TG 16:0/18:1(9Z)/18:1(11Z)
Acyl-alkyl TG O-52:2 TG 51:22 TG O-16:0_18:1_18:1 TG O-16:0/18:1/18:1 TG O-16:0/18:1(9Z)/18:1(11Z)
Acyl-dialkyl TG dO-52:2 TG 50:22 TG O-18:1_O-16:0_18:1 TG O-18:1/O-16:0/18:1 TG O-18:1(9Z)/O-16:0/18:1(9Z)
Trialkyl TG tO-52:2 TG 49:22 TG O-18:1_O-16:0_O-18:1 TG O-18:1/O-16:0/O-18:1 TG O-18:1(9Z)/O-16:0/O-18:1(9Z)
TG-Estolide TG 68:3;O2 TG 18:1_18:1_32:1;O2 TG 16:0;O(FA 16:0)/18:1/18:1 TG 16:0;2O(FA 16:0)/18:1(9Z)/18:1(11Z)
TG estolide structure
1 Annotation based on exact mass measurements using a high-resolution mass spectrometer, which allows differentiation of isobaric acyl and alkyl species.
2 Annotation using low resolution MS including the assumption of acyl chains only.