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Radiosynthesis of various pyrimidine derivatives and determining their uptake into cells

Thesis (MTech (Chemistry))--Cape Peninsula University of Technology, 2009 / N3-substituted pyrimidine nucleoside derivatives containing either an iodovinyl moiety or an
allyl group, i.e. [121]-N3-(3-iodoprop-2-en- l -yl)thymidine, (1~-711 and e21]-N3-(prop-2-enl-
yl)-5-iodo-Z'-deoxyuridine, (1~_10, were synthesised and preliminarily evaluated by
determining their uptake into CHO-Kl cells. Compound e~-711 was designed to be a
delivery vector of 121: into the DNA of the cells, while (1~_10 was designed to serve as a
control. Compound (1231]-711 was also intended to have a higher metabolic radiochemical
stability than 5-iodo-Z'-deoxyuridine ([123I]_IUdR) for the therapeutic use in cancer. The
synthesis of the N3-substituted intermediate precursors 411, 5 and 9 was achieved by Nalkylation
of suitably' protected thymidine and 5-iodo-Z'-deoxywidine analogues,
respectively. The intmediate precursors for radiolabelling, 411 and 11, were obtained by
incorporating a trialkylstannyl group at the respective labelling positions prior to
radioidination. (1~1-711 was recovered from (1~_6G after acid-hydrolysis of the protecting
groups and 10 was obtained from direct oxidative iodination of11. The radiochemical yields
ranged from 73% to 91% at the end ofthe synthesis and radiochemical purities were in excess
of99"10 after HPLC purification.
The cell-uptakes ofthe radiotracers were carried out and assessed by a direct comparison with
the gold standard e23I]-IUdR, which is known to bephosphorylated and incorporated into the
DNA of cells during the cells S-phase. The cell-uptake results of (1~_711 and (1~-10 were
roughly 4% and 3% relative to [123I]-IUdR, respectively. The poor cell-uptake of (1~_10
suggested thatthe uptake into the cells is not influenced by the position of the iodine atom in
the molecule, but most probably by the availability of the N3-position in its non-substituted
form. As a result of its poor incorporation into cells, it was concluded that the synthesised
radiotracer (1231]_711 would be a poor candidate for use in the eradication ofmalignant cells.

Identiferoai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:cput/oai:localhost:20.500.11838/744
Date January 2009
CreatorsTaleli, Lebusetsa
ContributorsVan der Walt, T.N., Prof, Rossouw, D.D., Dr
PublisherCape Peninsula University of Technology
Source SetsSouth African National ETD Portal
LanguageEnglish
Detected LanguageEnglish
TypeThesis
Rightshttp://creativecommons.org/licenses/by-nc-sa/3.0/za/

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