POSITION OF URIDINE THIATION - IDENTIFICATION OF MINOR NUCLEOSIDES FROM TRANSFER RNA BY MASS SPECTROMETRY

The position of uridine or uracil thiation may be deduced on the basis of mass spectral fragmentation patterns. Unlike other methods of differentiation, neither chemical conversions nor model compounds are required, and the procedure appears to be independent of substituents on the uracil nucleus. The fragmentation pattern of the base moiety of the nucleoside, which involves the formal loss of HCNO(S) from a uracil (or 2-thiouracil), has been observed to be consistent for uracil, 2-thiouracil, 4-thiouracil, 2,4-dithiouracil, and for many substituted uracils and uridines. © 1969.