Cytosine Electricity

Many years later, Schwartz (Schwartz and Goverde, 1982 Voet and Schwartz, 1983) discovered that the synthesis of adenine via polymerisation of HCN can be accelerated by adding formaldehyde and other aldehydes. Reactions in the gas phase (nitrogen/methane atmosphere) promoted by electrical discharges led to the formation of cyanoacetylene in relatively good yields the latter reacts with urea to give various products, including cytosine (Sanchez et al., 1968). 

Bradbury et al. (1967) have studied partial nucleoproteins produced by removal of histone fractions from nucleohistone. Figure 12.6 shows a polarized infrared spectrum of one of the nucleoproteins oriented by shearing. The spectrum is that of a film deuterated by D2O vapor. The bands of the in-plane vibrations of cytosine and guanine moieties are highly polarized when the electric vector is placed perpendicular to the fiber axis. The 1452 cm absorption is that of the amide IF band (Miyazawa et al., 1956 Miyazawa, 1962) for the readily deuterated fraction of the partial nucleoprotein. As seen in Fig. 12.6, the 1452 cm band is polarized considerably in the direction parallel to the fiber axis, giving evidence that the extended polypeptide chain is situated so that its axis lies between the angle of the groove in the DNA double helix and the axis of the DNA helices (Bradbury et al., 1967). 

Ejfect of anions on capacitance pits. The presence of bromine, iodine and sulphate anions in the cytosine solutions can induce the two-dimensional condensation of cytosine at the electrically neutral electrode surface [66]. The halogen ions can induce a new potential region of condensation also with adenine [67]. The two-dimensional condensation of adenine induced by bromine ions is much slower than the condensation of adenine molecules alone [67], Fig. 6. 

Some time ago, I postulated a route involving the condensation of a, / -unsaturated three-carbon compounds (e.g. acrylonitrile) with urea for the synthesis of pyrimidines. Very small yields of uracil were obtained in this manner in our laboratory. - A better C3 precursor appears to be cyanoacetylene, which, after HCN, is the major nitrogen-containing product formed from methane and nitrogen by electrical discharges. Cyanoacetylene condenses with urea or cyanate to form cytosine in 20 % yield as shown by Sanchez, et. Cytosine is readily converted into uracil by deamination. Furthermore, by... 

Two other important interactions must be considered in the case of protonated pairs the induction interaction and the molecular ion - dipole interaction, i.e., interaction of the charged monomer with the electric field (dipole moment) of the neutral monomer. This interaction is very strong in protonated pairs with a highly polar neutral monomer. For example, the calculated gas-phase complexation energy of the triply-bonded CCH pair is -45 kcal/mol. The molecular ion - dipole interaction leads to protonation of adenine in the (AC)H pair. The strong electric field around cytosine shifts the proton to adenine [32b] despite that for isolated bases protonation of cytosine is preferred. 

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