Nucleotides aqueous solutions

Steenken, S. (1989). Purine bases, nucleosides and nucleotides aqueous solution redox chemistry and transformation reactions of their radical cations and e" and OH adducts. Chem. Rev. 89, 503-520. 

Steenken S (1988) Electron transfer between radicals and organic molecules via addition/elimina-tion. An inner-sphere path. In Rice-Evans C, Dormandy T (eds) Free radicals chemistry, pathology and medicine. Richelieu Press, London, pp 53-71 Steenken S (1989) Purine bases, nucleosides and nucleotides Aqueous solution redox chemistry and transformation reactions of their radical cations e and OH adducts. Chem Rev 89 503-520 Steenken S (1992) Electron-transfer-induced acidity/basicity and reactivity changes of purine and pyrimidine bases. Consequences of redox processes for DNA base pairs. Free Radical Res Commun 16 349-379... 

Nucleotides are phosphoric acid esters of nucleosides Those derived from adenosine of which adenosine 5 monophosphate (AMP) is but one example are especially promi nent AMP is a weak diprotic acid with s for ionization of 3 8 and 6 2 respectively In aqueous solution at pH 7 both OH groups of the P(0)(0H)2 unit are ionized... 

By structural complementarity, dicationic l,4-diazabicyclo[2.2.2]octane (VII) provides an appropriate recognition site for phosphate ions and two stearyl side chains attached to the amines add lipophilic properties 59,60). Such a carrier model can selectively extract nucleotides from aqueous solution to chloroform solution via lipophilic salt formation. The order of nucleotide affinity is ATP > ADP > AMP. The selectivity ratios were 45 for ADP/AMP and 7500 for ATP/AMP at pH 3. The relative transport rate was ATP > ADP > AMP. The ratios were 60 for ATP/AMP and 51 for ADP/AMP. The modes of interaction of ADP and ATP are proposed to be as shown in Fig. 6. 

Formation constants for complex species of mono-, di-, and trialkytin(rV) cations with some nucleotide-5 -monophosphates (AMP, LIMP, IMP, and GMP) are reported by De Stefano et al. The investigation was performed in the light of speciation of organometallic compounds in natural fluids (I = 0.16-1 moldm ). As expected, owing to the strong tendency of organotin(IV) cations to hydrolysis (as already was pointed above) in aqueous solution, the main species formed in the pH-range of interest of natural fluids are the hydrolytic ones. ... 

Depicted in Fig. 2, microemulsion-based liquid liquid extraction (LLE) of biomolecules consists of the contacting of a biomolecule-containing aqueous solution with a surfactant-containing lipophilic phase. Upon contact, some of the water and biomolecules will transfer to the organic phase, depending on the phase equilibrium position, resulting in a biphasic Winsor II system (w/o-ME phase in equilibrium with an excess aqueous phase). Besides serving as a means to solubilize biomolecules in w/o-MEs, LLE has been frequently used to isolate and separate amino acids, peptides and proteins [4, and references therein]. In addition, LLE has recently been employed to isolate vitamins, antibiotics, and nucleotides [6,19,40,77-79]. Industrially relevant applications of LLE are listed in Table 2 [14,15,20,80-90]. 

The Zn-N3imide interaction has been used to selectively extract imide-containing nucleosides and nucleotides into lipophilic media (39). Hexadecyl-derivatized Zn2+-cyclen was shown to extract dT from an aqueous solution containing a mixture of C, A, and G nucleobases. The antiviral agent AZT (3 azido-3 deoxythymidine) could also be extracted into CHCI3 from neutral aqueous solutions. Transport across a lipophilic layer was also shown, using acidic conditions, to promote the release of dT and AZT (Fig. 9). 

Whereas imidazolides of nucleotides react only in organic solvents with phosphates or pyrophosphates to give the corresponding anhydride derivatives in high yield, ATP can also be formed enzymatically in aqueous solution from AMP-Im with inorganic pyrophosphate in the presence of valyl-f-RNA synthetase.[66] A variant of this method is the one-pot reaction of a nucleoside with phosphoryltristriazole and tributylammonium pyrophosphate. 671 An a-methylphosphonyl-/ ,y-diphosphate of a thymidine derivative has been synthesized in a similar way t681... 

Shaw and co-workers during studies into the de novo biosynthesis of purine nucleotides demonstrated that 4(5)-aminoimidazole (25 R = H) on treatment with a saturated aqueous solution of potassium bicarbonate at 70°C for 15 min gave 4-aminoimidazole-5-carboxylic acid (38) in an estimated yield of 40% [71JCS(C)1501]. This and related reactions are discussed in more detail in Section V,B,4. 

Mudd, Mudd et Menzel, and Nasr et have reported that ozonization of aqueous solutions of NADH or NADPH results in their oxidation. However, there is a difference in their findings as to whether the resulting product is a biologically active oxidized pyridine nudeotide (NAD or NADP), as suggested by Menzel, or is molecularly disrupted to the extent that it is unable to participate in enzymatic processes. Inasmuch as more drastic effects are likely to be observed in vitroy it is more likely that oxidation of intracellular reduced pyridine nucleotides proceeds mainly to NAD or NADP after ozone inhalation but further resolution of this question would be of value. 

Buryak, A. Pozdnoukhov, A. Severin, K. Pattern-based sensing of nucleotides in aqueous solution with a multicomponent indicator displacement assay. Chem. Commun. 2007, 2366-2368. 

There has been continued interest in the radiation chemistry of the purines since early reports on oriented DNA by Graslund et al. [35] which suggest that the main trapping site of one-electron oxidation in DNA is the guanine base. It is remarkable that in aqueous solution, the electron adducts of the purine nucleosides and nucleotides undergo irreversible protonation at carbon with a rate constant 2 orders of magnitude higher than that for carbon protonation of the electron adduct in thymidine [36]. It is therefore important to know the properties of the various purine reduction products and to ask why they have not been observed in irradiated DNA. 

In an aqueous solution of DNA, the water outside of the solvation shell is referred to as bulk water. When DNA solutions are frozen, the bulk water crystallizes as a separate phase—ice. Ice does not form if the concentration of DNA is brought to a level where only the solvation shell remains, about 20-22 waters/nucleotide. If brought to this concentration slowly, a film is formed. Freezing a film does not create ice. Another type of sample is prepared by first lyophilizing DNA and then letting it sit at a preselected humidity that determines the level of hydration, typically 2.5 < F < 22. Subsequent freezing of these cotton-like samples does not yield ice. 

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