TABLE 1.
Proposed structures for lipid A obtained from Xac wild type LPS after MALDI-TOF mass spectrometry analysis in the positive ion mode (sugar backbone: [GlcNH2-GlcNH2])
| Masscalc.a [M + Na]+ | Massmeas.b [M + Na]+ | Proposed structures | PP-EtNH2 | P-EtNH2 | |
|---|---|---|---|---|---|
| Penta-acylated (a) | 1667.9 | 1667.9 | C10:0 C13:0(OH) C11:0 C15:0 C9:0 | 2 | |
| 1653.9 | 1653.2 | C10:0 C13:0(OH) C11:0 C14:0 C9:0 | 2 | ||
| 1603.9 | 1603.6 | C11:0 C13:0(OH) C11:0 C13:0 (OH) C10:0 | 1 | 1 | |
| 1587.9 | 1588.6 | C10:0 C13:0(OH) C11:0 C14:0 C10:0 | 1 | 1 | |
| 1573.9 | 1572.9 | C10:0 C13:0(OH) C11:0 C14:0 C9:0 | 1 | 1 | |
| 1559.9 | 1560.9 | C10:0 C13:0(OH) C11:0 C14:0 C8:0 | 1 | 1 | |
| 1545.8 | 1545.2 | C10:0 C12:0(OH) C11:0 C14:0 C8:0 | 1 | 1 | |
| 1533.8 | 1534.5 | C 8:0 C11:0(OH) C11:0 C12:0(OH) C9:0 | 1 | 1 | |
| Tetra-acylated (b) | 1433.8 | 1434.6 | C13:0(OH) C11:0 C14:0 C10:0 | 1 | 1 |
| 1419.8 | 1419.2 | C13:0(OH) C11:0 C14:0 C9:0 | 1 | 1 | |
| 1405.8 | 1403.4 | C13:0(OH) C11:0 C14:0 C8:0 | 1 | 1 | |
| 1391.7 | 1391.6 | C12:0(OH) C11:0 C14:0 C8:0 | 1 | 1 | |
| 1377.7 | 1376.7 | C11:0(OH) C11:0 C14:0 C8:0 | 1 | 1 |
a calc., calculated monoisotopic masses.
b meas. measured monoisotopic masses.