8-[O-18]Hydroxy-2'-deoxyguanosine was synthesized starting from 8-brom
o-2'-deoxyguanosine and the sodium salt of [O-18]benzyl alcohol, resul
ting in the intermediate 8-[O-18]benzyloxy-2'-deoxyguanosine. Subseque
nt reduction by catalytic transfer hydrogenation, yielded the desired
product 8-[O-18]hydroxy-2'-deoxyguanosine. 8-Bromo-2'-deoxyguanosine w
as synthesized from 2'-deoxyguanosine by treatment with Br-2. The sodi
um salt of [O-18]benzyl alcohol was prepared by treatment of ethyl ben
zimidate hydrochloride with (H2O)-O-18 (95%), LiAlH4 and sodium hydrid
e. Starting from (H2O)-O-18 the overall yield of 8-[O-18]hydroxy-2'-de
oxyguanosine was approximately 4%. The isotopic purity was calculated
to be 93.4 atom% based on CC-MS measurements. The chemical purity and
the isotopic purity comply with the planned application, namely as int
ernal standard for the determination of 8-hydroxy-2'-deoxyguanosine by
CC-MS,