Table 1.
Lipid classes, metabolic pathways, employed chromatography platform/ionization polarity, and a number of molecular species profiled in the study.
| LIPID MAPS Class 1 | Sub-Pathway 2 | KEGG Map 2 | Detection Platform 3 | No of Species |
|---|---|---|---|---|
| Fatty acyls | Fatty acids, free saturated | 01212 | LC/MS Neg, GC/MS | 16 |
| Fatty acyls | Fatty acids, free unsaturated | 01040 | GC/MS | 20 |
| Fatty acyls | Fatty acids, hydroxy | 00073 | LC/MS Polar | 7 |
| Fatty acyls | Fatty acids, amide and amino | 00061 | LC/MS Pos Early, LC/MS Pos Late | 3 |
| Fatty acyls | Fatty acids, dicarboxylate | 00071 | LC/MS Polar | 9 |
| NA | Carnitine metabolism | 00260 | LC/MS Pos Early | 5 |
| NA | Hormone metabolism | 04075 | LC/MS Neg, LC/MS Polar | 4 |
| Glycerolipids | Glycerolipids, monoacyl | 00561 | LC/MS Neg | 5 |
| Glycerolipids | Glycerolipids, diacyl | 00561 | LC/MS Pos Late | 3 |
| Glycerophospholipids | Galactolipids | 00564 | LC/MS Pos Late | 13 |
| Glycerophospholipids | Lyso-galactolipids | 00564 | LC/MS Pos Late, LC/MS Neg | 6 |
| Glycerophospholipids | Sulfolipids | 00564 | LC/MS Neg | 3 |
| Glycerophospholipids | Phospholipids | 00564 | LC/MS Pos Late | 23 |
| Glycerophospholipids | Lyso-phospholipids | 00564 | LC/MS Pos Late | 11 |
| NA | Phospholipid metabolism | 00564 | LC/MS Pos Early, LC/MS Polar | 7 |
| NA | Choline metabolism | 00564 | LC/MS Pos Early | 4 |
| Sphingolipids | Sphingolipids | 00600 | LC/MS Pos Late | 6 |
| Sterol lipids | Sterols | 00100 | LC/MS Pos Late | 3 |
| Prenol lipids | Tocopherol metabolism | 00130 | LC/MS Pos Late | 3 |
| NA | Carotenoid/Chlorophyll metabol | 00860/00906 | LC/MS Pos Late, LC/MS Neg | 7 |
| Unknown lipids | NOT APPLICABLE (NA) | NA | LC/MS Neg, LC/MS Pos Early | 50 |
1 Lipids were classified according to the Lipid Metabolites and Pathways Strategy (LIPID MAPS, https://www.lipidmaps.org). 2 Pathways were classified according to Metabolon Pathway Orders (Metabolync™, https://www.metabolon.com) and the Kyoto Encyclopedia of Genes and Genomes (KEGG, https://www.genome.jp/kegg/). 3 Five different chromatographic conditions were used in the Lipidomic platform and are described in the “Materials and Methods” Section.