Nitrosative Guanine Deamination. Ab Initio Study of the Intrinsic Plausibility of Deglycation of N-Protonated 5-Cyanoimino-4-Oxomethylene-4,5-Dihydroimidazoles

Sundeep Rayat and Rainer Glaser

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Figure Legends

Figure 1. Cyano-N protonated cations 6a (R = CH3) and 8b-Sg (R = MOM), and Imino-N protonated cations 7a (R = CH3) and 9a-Sg (R = MOM).
6a, 8b-Sg, 7a, 9a-Sg.

Figure 2. N-[4-(oxomethylene)-imidazol-5-yl]carbodimide 10 and N-[4-(oxomethylene)-imidazol-5-yl]cyanamide 11.
10b, 11a, 11b.

Figure 3. Methyl and methoxymethyl cations 12 and 13 and their water aggregates 14 and 15. Two Cs conformations for the methoxymethyl cation were optimized, the cis-ip 13 and the trans-ip 13' as shown (ip refers to in-plane). The vibrational analysis revealed that the former is a minimum while later a transition state.
12, 13, 13', 14, 15.

Figure 4. Pre-coordination complex 16, post-coordination complex 20 and the transition state 24.
16, 20, 24.

Figure 5. Pre-coordination complex 17, post-coordination complex 21 and the transition state 25.
17, 21, 25.

Figure 6. Pre-coordination complex 18, post-coordination complex 22 and the transition state 26.
18, 22, 26.

Figure 7. Pre-coordination complex 19, post-coordination complex 23 and the transition state 27.
19, 23, 27.