Post-graduate theses
Current Record: 4885 of 6576
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Identifier |
000035758 |
Title |
Σύνθεση των 5'-tert-Βουτυλοκετονών της ριβο - και 2'-Δεοξυριβο-Γουανοσίνης για την ανεξάρτητη παραγωγή C-5' Νουκλεοζιτικών ριζών |
Author
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Γεωργανάκης, Δημήτριος
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Thesis advisor
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Γκιμήσης, Αθανάσιος
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Abstract |
One of the most common actions of oxidative damage in the DNA is the abstraction of a hydrogen atom from the nucleotide deoxyribose. The chemospecific synthesis of nucleoside models as precursors for the formation of free radicals on the deoxyribose positions, has helped the study of the oxidative damage reaction pathways and the understanding of the mechanisms that take place. The C-5 chemistry has an important part in oxidative damage pathways due to its favorable position for abstraction in the minor groove of the DNA double helix. The formation of a free radical on the C-5 position has been the goal of the present study. In order to achieve a chemospecific formation of a C-5 radical we placed a photolabile group like tert-butyl ketone on the 5 position of guanosine and 2-deoxyguanosine substrates. The photolabile groups underwent a photolysis reaction under ultraviolet radiation that led to the formation of the C-5 radical and some useful results that can help the understanding of the mechanisms that takes place after the formation of the radical. The photolysis of the photolabile precursors under anaerobic conditions and the presence of reductive compounds leads to the formation of two new products as a result of two different and competitive reaction pathways, the reduction pathway (A) and the cyclisation pathway (B). The 5-8 cyclopurine has also been identified after the radiation of DNA solutions, and is considered to be a poor substrate for the repair enzymes of DNA and a potential cytotoxic compound. The formation of this product under an intramolecular attack of the C-5 radical to the purine has offered
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Language |
Greek |
Issue date |
2002-07-01 |
Collection
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School/Department--School of Sciences and Engineering--Department of Chemistry--Post-graduate theses
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Type of Work--Post-graduate theses
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Permanent Link |
https://elocus.lib.uoc.gr//dlib/e/a/a/metadata-dlib-2002georganakis.tkl
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Views |
180 |