Adenine zinc complexes

The interaction of nine nucleobases (thymine, uracil, dihydrouracil, cytosine, adenine, guanine, diaminopurine, xanthine, hypoxanthine), in their deprotonated form, with zinc and with themselves in [Zn(nucleobase)(Tpph Me)] has been investigated. Selected compounds have been characterized by single-crystal X-ray study.158 Gelinski et al. reported the synthesis and characterization of two zinc complexes containing the ligand Tpph,Me and glutathione derivatives (Fig. 3.28).159... 

Acetic acid, iodo-inhibitor binding dehydrogenases, 1016 Acetone, acetyl-zinc complexes, 967 Adenine... 

A number of zinc and cadmium complexes of adenine (82),554,555 adenine N-oxide,556 guanine,557 inosine,558 cytidine559 and other nucleosides560 have been studied. The structure of (9-methyladenine)ZnCl2 is polymeric each zinc ion is tetrahedrally coordinated to two chlorine atoms (Zn—Cl = 2.22 A), and to N-l and N-7 of neighbouring adenine moieties (Zn— N = 2.05A).561 A structural study of the related cadmium complex, CdCl2(DMSO)L (L = 9-methyladenine), has shown the complex to form a one-dimensional polymer. 2... 

Nucleobases and nucleosides are common motifs for hydrogen-bonded supramolecular arrays. Ng et al. first reported a series of phthalocyanine-nucleobase conjugates [64], The tetra-adenine phthalocyanine 64 was prepared by standard <9-alkylation of zinc(II) tetrahydroxyphthalocyanine with 9-(2-bromoethyl)adenine in the presence of K2CO3. The fluorescence of 64 is quenched substantially upon addition of thymine-substituted 9,10-anthraquinone 65, and the rate is much faster compared with that for the situation when the unsubstituted 9,10-anthraquinone is used as the quencher. These results suggest that 64 forms a supramolecular complex with 65 through the Watson-Crick base-pairing interactions. 

A novel class of nucleic acid mimics has been described which possess two ethylenediamine moieties for intermolecular metal co-ordination (25). In the presence of Zn + ions and template DNA, the analogues (25) form relatively stable structures, stabilised by the co-ordination of adjacent chelating moieties with zinc ions. It was shown that with an oligothymidine template and the adenine derivative of (25) that a 2 1 complex was formed, which showed a biphasic melting transition. Short RNA duplexes (3-4 bp) are considerably stabilised if both termini of the duplexes are bridged by non-nucleotidic linkers. For example, the pairing of rGAA with rUUC in such a cyclic system exhibits a Tm of 36°C in IM salt solution. 

Figure 21 Schematic representation of molecular imprinting of 9-ethyl adenine (9EA) using 5,10,15-tris(4-isopropylphenyl)-20-(4-methacyloloxyphenyl)porphyrin zinc (II) complex and methacrylic acid as a functional monomer.

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