Table 1.
Uridine nucleoside derivatives identified in the tRNAs of N. equitans and I. hospitalis
| Compound notation and retention time (RT in min) | Archaeon | m/z (negative/positive ion modes) | Molecular composition | Nucleoside | Nucleoside standards for comparison | Notes | |
|---|---|---|---|---|---|---|---|
| #1 | 1.2 | I. hospitalis & N. equitans | 243.062/245.077 | C9H12N2O6 | Ψ | Ψ | a |
| #2 | 1.5 | I. hospitalis & N. equitans | 243.062/245.077 | C9H12N2O6 | U | U | a |
| #3 | 1.5 | I. hospitalis | 257.078/259.093 | C10H14N2O6 | m1Ψ | m1Ψ | a,b |
| #4 | 2.6 | N. equitans | 257.078/259.093 | C10H14N2O6 | m5U | m5U | a,b |
| #5 | 3.2 | I. hospitalis & N. equitans | 257.078/259.093 | C10H14N2O6 | Um | Um | a |
| #6 | 2.5 | I. hospitalis | 273.055/275.070 | C10H14N2O5S | m1s4Ψ | Ψ, m1Ψ, s2Ψ | c |
| #7 | 4.4 | N. equitans | 273.055/275.070 | C10H14N2O5S | m5s2U | m5s2U | a |
| #8 | 4.8 | I. hospitalis | 273.055/275.070 | C10H14N2O5S | s2Um | m5s2U, s2U, s4U, Um | c |
| #9 | 1.6 | N. equitans | 259.039/261.054 | C9H12N2O5S | s4Ψ | Ψ, s2Ψ | b,c |
| #10 | 3.0 | I. hospitalis & N. equitans | 259.039/261.054 | C9H12N2O5S | s2U | s2U | a |
| #11 | 3.7 | I. hospitalis & N. equitans | 259.039/261.054 | C9H12N2O5S | s4U | s4U | a |
| #12 | 3.0 | I. hospitalis | 271.094/273.108 | C11H16N2O6 | m1Ψm | m1Ψ, m3Ψ, m1U | c |
aStructures confirmed by mass determination, chromatographic retention time (RT) and tandem MS (MS/MS) fragmentation analyses of compound and comparison with identical chemically synthesized standard.
bPresent in small amounts compared to the other modified nucleosides.
cNo identical synthetic standard available. Structures deduced from mass determination, isotope distribution, tandem MS analyses and comparison with related (nonidentical) standards to identify and exclude known nucleoside fragments.