2 -Deoxyguanosine complexes

CjoH13N504 C9H12BrN304 5-Bromo-2 -deoxycytidine - 2 -deoxyguanosine complex DGUBCY 31 370... 

C10H13N8O4 Ce2H86N12Ole 12 H20 Bis(2 -deoxyguanosine)-actinomycin complex, dodecahydrate ACTDGU10 30 460... 

The antiviral nucleotide analogue 9-[2-(phosphonomethoxy)ethyl]-2,6-diaminopurine also uses its N7 as a major binding site and forms a N7-phosphonate macrochelate (698).1833 Another antiviral analogue of 2 -deoxyguanosine, acyclovir (9-[(2-hydroxyethoxy)-methyl]guanine) forms with Ni11 a bis-complex with two N7 coordinated in trans position to each other.1834... 

D-ribofuranosyl)-uracil-5-yl] disulfide Hydrogen-bonded complex of 2 -deoxyguanosine and 5-bromo-2 -deoxycytidine C-3 C-2 endo C-2 endo C-4 0.454 0.540 102... 

ATP -I- 2 -deoxynucleoside = ADP + 2 -deoxynucleoside 5 -phosphate (<1>, compulsory ordered steady-state reaction mechanism with formation of a ternary complex with the phosphate donor and acceptor [2] the enzyme from embryonic cells of Drosophila melanogaster differs from other deoxynucleoside kinases [EC 2.7.1.76 (deoxyadenosine kinase) and EC 2.7.1.113 (deoxyguanosine kinase)] in its broad specificity for all four common deoxynucleosides)... 

An example has been published (11) in which TIBO R82150 [126320-77-2] (6), an inhibitor of the HIV-1 RT, is noncompetitive with respect to one substrate, deoxyguanosine triphosphate (AirTP), yet uncompetitive with respect to the second, the template—primer complex poly(C) (dG)12 18. The IC50... 

Lastly, electron transfer in D—[H]—A assemblies is not a perquisite of the excited states of metal complexes. Organic ensembles 38 and 39 (R = SiMe2 Bu), containing a dimethylaniline-anthracene redox pair, have been synthesized recently [124]. Preliminary time-resolved and steady-state fluorescence experiments indicate the occurrence of photoinduced electron transfer. In work related to Watson Crick base-paired systems, the excited state of the fluorescent pyrene derivative 40 is efficiently quenched (94-99 %) by 2 -deoxyguanosine (dG), 2 -deoxycytidine (dC), or 2 -deoxythymidine (dT) in aqueous solution [125]. A PCET mechanism is thought to be responsible for this process, as the thermodynamics of electron transfer are unfavorable unless coupled to a rapid proton-transfer step. The quenched lifetime of 40 in the presence of dC and dT in H2O is significantly extended by a factor of 1.5-2.0 in D2O this isotope effect is similar to that observed in the kinetics studies of 1 [70]. The invoked PCET reaction mechanism also accounts for the inability of dC and dT to quench the fluorescence of 40 in the aprotic organic solvent DMSO. 

Production of ROS, factors involved in the aging process (Finkel and Holbrook, 2000), is elevated in AD brain and may be an important cause of AD (Martins et al., 1986). Elevated levels of oxicUzed hpids (lipid peroxidation, maloncUaldehyde, 4-hydroxynonenal) (Markesbery and Carney, 1999), proteins (advanced glycation end product mocUfications, tyrosine nitration) (Good et al., 1996 Takeda et al., 1998), and nucleic acids (8-hydroxy-deoxyguanosine) have been documented in AD brains (Lyras et al., 1997). Mitochondria and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex... 

A zinc(II) complex of 1,4,7,10-tetraazacyclododecane with a pendent acridine unit (Figure 76) has shown tight binding with N3-deprotonated 2 -deoxythymidine (dT) (log Aa of 7.2) [102]. The acridine unit was found to increase the binding by a factor of 60. Also 2 -deoxyguanosine (dG) in its NI-deprotonated form showed a log of 5 whereas 2-deoxycytidine (dC) and 2-deoxyadenosine (dA) did not bind at all. 

The results obtained by various workers employing these several techniques are not in total agreement. It seems clear, however, that the presence of deoxyguanosine residues in DNA is required for binding of Actino-mycin D. Anthracyclines can complex with poly dAT and poly dGdC however, binding of nogalamycin may be favored by dAT pairs while that of daunomycin is not. The presence of cations (Mg" or Cs" ) may play a role in complex formation between the chromomycin antibiotics and DNA. 

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