16434-11-0Relevant academic research and scientific papers
Deoxyribose-5-phosphate aldolase as a catalyst in asymmetric aldol condensation
Chen, Lihren,Dumas, David P.,Wong, Chi-Huey
, p. 741 - 748 (1992)
This paper describes the substrate specificity and synthetic utility of deoxyribose-5-phosphate aldolase (DERA, EC 4.1.2.4). Eight donors and 20 acceptors have been tested as substrates. In addition to acetaldehyde, propanal, acetone, and fluoroacetone have been used to condense with a number of acceptor aldehydes. Thirteen aldol products have been prepared and characterized. A new stereogenic center with 3(S) configuration is formed when acetaldehyde, fluoroacetone, or acetone is used as a donor substrate. With propanal, two new stereogenic centers are formed with 2(R) and 3(S) configurations. The acceptor substrates have very little structural requirements. The 2-hydroxyaldehydes appear to react the fastest, and the D-isomers are better substrates than the L-isomers. The stereospecificity is absolute regardless of the chirality of 2-hydroxyaldehydes. The aldol reactions thus follow the Cram-Felkin mode of attack for D-substrates and anti-Cram-Felkin mode of attack for L-substrates.
γ-Radiolysis of 2'-Deoxycytidine-5'-phosphate in Deoxygenated Aqueous Solutions. OH Radical-Induced Alterations at the Sugar Moiety
Schuchmann, Heinz-Peter,Wagner, Rita,Sonntag, Clemens von
, p. 1213 - 1220 (2007/10/02)
In order to elucidate some aspects of the mechanism of radical-induced strand break formation in DNA, the γ-radiolysis of N2O-saturated aqueous solutions of 2'-deoxycytidine-5'-phosphate has been studied as a model system.At pH 4 it has been observed that upon OH attack at the sugar moiety phosphate (G ca. 0.6) and cytosine (G = 1) are released and the following cytosine-free sugars are formed: 2,5-dideoxypentos-3,4-diulose, 1 (G = 0.22), 2-deoxy-pentos-4-ulose, 2 (G = 0.18), 2-deoxy-pentos-4-ulose-5-phosphate, 3 (G = 0.06), 2-deoxypentoic acid-5-phosphate and its lactone, 5 (G ca. 0.5).Some 2-deoxyribose-5-phosphate, 4 is also formed.Upon addition of H2O2 (up to 1E-2 M) prior to irradiation, G(1) is drastically reduced without giving rise to another cytosine-free product.G(3) increases at the expense of G(2).G(4+5) also increase upon H2O2 addition.The formation of these products and the change of their G values as a function of H2O2 concentration are discussed in the light of well-documented radical reactions of carbohydrates and related compounds.The precursor of 1 has been considered to be the radical at C-3', that of 2 and 3 the radical at C-4' and that of 5 the radical at C-1'.Product 4 is though to arise from a radical-induced destruction of the cytosine moiety.These primary radicals which may undergo rearrangement, or eliminate phosphate, are readily oxidised by H2O2, a reaction which leads to the change of product distribution mentioned above. - Key words: Free Radicals, Radical Cations, Carbohydrates, DNA Model
