Table 1.
Relative quantitation of MMPE and PE molecular species present in soil microbes resolved from HILIC-MS chromatograms in negative ion mode.
| RT (min) | m/z | Prec. Ion | Molecular species | Diacyl species | % nmol |
|---|---|---|---|---|---|
| 18.16 | 646.4820 | [M-H]− | PE O-30:1 | O-15:0/15:1 | 2.57 ± 0.07 |
| 17.68 | 660.4613 | [M-H]− | PE 30:1 | 15:0/15:1 | 5.18 ± 0.14 |
| 18.32 | 662.4770 | [M-H]− | PE 30-0 | 15:0/15:0 | 4.01 ± 0.09 |
| 17.95 | 672.4977 | [M-H]− | PE P-32:1 | P-16:0/16:1 | 2.48 ± 0.04 |
| 12.51 | 674.4767 | [M-H]− | MMPE 30:1 | 15:1-15:0 | 0.66 ± 0.02 |
| 17.87 | 674.4767 | [M-H]− | PE 31:1 | 16:1-15:0 | 6.80 ± 0.04 |
| 12.36 | 686.4767 | [M-H]− | MMPE 31:2 | 15:1-16:1 | 0.18 ± 0.01 |
| 17.61 | 686.4767 | [M-H]− | PE 32:2 | 16:1/16:1 | 11.33 ± 0.07 |
| 12.67 | 688.4925 | [M-H]− | MMPE 31:1 | 16:1/15:0 | 2.26 ± 0.03 |
| 18.01 | 688.4925 | [M-H]− | PE 32:1 | 16:0-16:1, 17:1/15:0 | 12.08 ± 0.06 |
| 12.40 | 700.4925 | [M-H]− | MMPE 32:2 | 16:1/16:1 | 3.61 ± 0.17 |
| 17.60 | 700.4925 | [M-H]− | PE 33:2 | 16:1-17:1 | 5.08 ± 0.15 |
| 12.76 | 702.5080 | [M-H]− | MMPE 32:1 | 16:0/16:1, 17:1/15:0, 18:1/14:0 | 2.77 ± 0.10 |
| 18.22 | 702.5080 | [M-H]− | PE 33:1 | 16:0/17:1, 17:0-16:1, 18:1/15:0 | 8.53 ± 0.06 |
| 12.41 | 714.5080 | [M-H]− | MMPE 33:2 | 17:1-16:1 | 1.54 ± 0.08 |
| 17.79 | 714.5080 | [M-H]− | PE 34:2 | 18:1-16:1, 17:1/17:1, 16:0/18:2 | 9.65 ± 0.28 |
| 12.87 | 716.5239 | [M-H]− | MMPE 33:1 | 16:0-17:1, 17:0-16:1, 18:1/15:0 | 2.40 ± 0.06 |
| 18.53 | 716.5239 | [M-H]− | PE 34:1 | 17:1/17:0, 16:0/18:1, 18:0/16:1 | 3.75 ± 0.10 |
| 12.50 | 728.5239 | [M-H]− | MMPE 34:2 | 18:1/16:1, 17:1/17:1 | 2.59 ± 0.07 |
| 18.01 | 728.5239 | [M-H]− | PE 35:2 | 18:1/17:1, 16:1-19:1 | 2.47 ± 0.02 |
| 17.52 | 740.5239 | [M-H]− | PE 36:3 | 18:1-18:2 | 0.85 ± 0.07 |
| 12.63 | 742.5395 | [M-H]− | MMPE 35:2 | 17:1-18:1 | 0.76 ± 0.03 |
| 18.34 | 742.5395 | [M-H]− | PE 36:2 | 18:1/18:1 | 5.18 ± 0.19 |
| 12.99 | 756.5551 | [M-H]− | MMPE 36:2 | 18:1/18:1 | 1.94 ± 0.01 |
| 19.15 | 756.5551 | [M-H]− | PE 37:2 | 18:1-19:1 | 1.32 ± 0.01 |
| Total% MMPE | 18.73 ± 0.50 | ||||
| Total% PE | 81.27 ± 0.50 | ||||
| Total% | 100 |
Values (percent by relative peak area) represent means ± standard errors, n = 4 per experimental replicate. PE represents phosphatidylethanolamine, MMPE represents N-monomethyl phosphatidylethanolamine subclass. The lipid components in the table are arranged based on m/z of the molecular species. If the position of fatty acyl chains on glycerol backbone was assigned, the molecular species was denoted with a slash sn-1/sn-2, if not a hyphen was used (e.g. PE 16:1-17:1) where the order of FA implies the more dominant molecular species and the hyphen indicates the presence of both sn-isomers8. Analysis was conducted using HILIC-HRMS/MS in negative ion mode.