Ester and related derivatives of ring N-pentafluorobenzylated 5-hydroxymethyluracil. Hydrolytic stability, mass spectral properties, and trace detection by gas chromatography-electron-capture detection, gas chromatography-electron-capture negative ion mass spectrometry, and moving-belt liquid chromatography-electron-capture negative ion mass spectrometry.
One consequence of radiation damage to DNA is the conversion of thymine to 5-hydroxymethyluracil (HMU). In order to sensitively detect this DNA adduct by gas chromatography (GC) or high-performance liquid chromatography (HPLC) with electron-capture detection techniques, it is necessary to derivatize it. This study was designed to select an optimum ester derivative of the aliphatic hydroxyl group on HMU. N1, N3-Bis(pentafluorobenzyl)-HMU was formed as a parent derivative, and from this a series of esters. Also O-pentafluorobenzyl and O-tetrafluorobenzyl ether derivatives were prepared. Of the esters the pivalyl derivative was the best choice because it formed easily, was relatively stable to aqueous hydrolysis (t 1/2 = 9.8 days at pH 11.5, 24 degrees C) and gave a response at fmol levels by GC and LC comparable to that of the ethers. Unanticipated was a good response as well for the parent derivative, a free hydroxyl compound, by GC and LC at this level. The work also demonstrates a high performance by LC-electron-capture negative ion mass spectrometry with a belt interface for the trace detection of derivatives of this type.
Barnett Institute of Chemical Analysis and Materials Science, Northeastern University, Boston, MA 02115.
G M
GM
Kresbach
M
M
Itani
M
M
Saha
E J
EJ
Rogers
P
P
Vouros
R W
RW
Giese
D055598:Chemical Phenomena; D002621:Chemistry; D002849:Chromatography, Gas / Q000379:methods*; D002853:Chromatography, Liquid / Q000379:methods*; D004249:DNA Damage; D004952:Esters / Q000032:analysis; D006868:Hydrolysis; D013058:Mass Spectrometry / Q000379:methods*; D010432:Pentoxyl / Q000031:analogs & derivatives* / Q000032:analysis; D014498:Uracil / Q000031:analogs & derivatives*
D004952:Esters; C008055:5-hydroxymethyluracil; D014498:Uracil; D010432:Pentoxyl