Table 2.
Fragments observed in CI mode GC/MS spectra of aldose-MOA and ketose-MOA. For both aldose-MOA and ketose-MOA, loss of acetate and ketene pendant groups dominated the spectra. Main chain C-C bond cleavage only observed for ketose-MOA.
| Molecular ion (m/z) | Fragment m/z values resulted from loss of acetate (m/z = 60) and/or ketene (m/z = 42) | Loss of main chain carbon Only observed in ketose-MOA | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| M | M-OAc | M-2OAc | M-2Ac | M-OAc-Ac | M-3OAc | M-2OAc-Ac | M-3OAc-Ac | M-C1 | M-(C1+C2) | |
| Hexose* | M-60 | M-2(60) | M-2(42) | M-60-42 | M-3(60) | M-2(60)-42 | M-3(60)-42 | |||
| Aldose | 420 | 360 | 300 | 331 | 318 | 240 | 258 | 198 | - | - |
| Ketose | 420 | 360 | 300 | - | 318 | 240 | - | 198 | 288 256 228 |
187 159 138 |
| Pentose** | ||||||||||
| Aldose | 348 | 288 | 228 | 259 | 246 | 168 | 187 | 126 | - | - |
| Ketose | 348 | 288 | 228 | - | 246 | 168 | - | 126 | 274 214 |
115 87 |
*
For hexoses-MOA (*), aldose-MOA are D-glucose-MOA, D-galactose-MOA, D-mannose-MOA, and ketose-hexose-MOA is D-fructose-MOA.
**
For pentoses-MOA (**), aldose-MOA are D-arabinose-MOA, D-ribose-MOA, and ketose-MOA are D-xylulose-MOA, D-ribulose-MOA