Oxygenated/oxidized phospholipids
PUFA-constituents having methylene-interrupted cis-double bonds (allylic double bonds) and/or polar headgroups having amino-residues are susceptible to oxidation with formation of ‘Oxygenated/oxidized Phospholipids’ (OxPL, OxPL-Nmod). OxPL is a general term for (sub)classes of lipids produced by several radical and/or enzymatic processes with various chirality that most often cannot be distinguished by MS analysis of the products.
Hierarchical shorthand notation for examples of oxygenated/oxidized phospholipids (OxPL)
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, Structure defined level: Molecular species with constituents and functional groups, Full structure level: Molecular species with constituents and functional groups including positions.
| Oxidative modification | Species level1 | Molecular species level | sn-Position level | Structure defined level | Full structure level |
|---|---|---|---|---|---|
| Hydroxylation | PC 36:4;O | PC 16:0_20:4;O | PC 16:0/20:4;O | PC 16:0/20:4;OH | PC 16:0/20:4(5Z,8Z,10E,14Z);12OH |
| PC 34:1;O2 | PC 16:0_18:1;O2 | PC 16:0/18:1;O2 | PC 16:0/18:1;(OH)2 | PC 16:0/18:1(9Z);12OH,13OH | |
| Epoxide | PC 34:2;O | PC 16:0_18:2;O | PC 16:0/18:2;O | PC 16:0/18:1;Ep | PC 16:0/18:1(9Z);12Ep |
| Hydroperoxide | PC 34:2;O2 | PC 16:0_18:2;O2 | PC 16:0/18:2;O2 | PC 16:0/18:2;OOH | PC 16:0/18:2(9Z,11E);13OOH |
| Peroxide | PC 34:2;O2 | PC 16:0_18:2;O2 | PC 16:0/18:2;O2 | PC 16:0/18:1;OO | PC 16:0/18:1(9Z);12OO |
| Aldehyde | PC 21:1;O | PC 16:0_5:1;O | PC 16:0/5:1;O | PC 16:0/5:0;oxo | PC 16:0/5:0;5oxo |
| Carboxylic acid | PC 25:1;O2 | PC 16:0_9:1;O2 | PC 16:0/9:1;O2 | PC 16:0/9:0;COOH | PC 16:0/9:0;8COOH |
| Hydroxy-Aldehyde | PC 26:3;O2 | PC 18:1_8:2;O2 | PC 18:1/8:2;O2 | PC 18:1/8:1;OH;oxo | PC 18:1(9Z)/8:1(6E);5OH;8oxo |
| PC sn-2 position | PC 36:4;O3 | PC 16:0_20:4;O3 | PC 16:0/20:4;O3 | PC 16:0/20:2;[cy5:0;OH;oxo];OH |
PC 16:0/20:2(5Z,13E);[8-12cy5:0;11OH;9oxo];15OH (common name 8-IsoPGE2-PC) 
|
1Annotation based on exact mass measurements using a high-resolution mass spectrometer, which allows differentiation of isobaric acyl and alkyl species.