Figure 2.

Degradation under acidic or neutral denaturation conditions. (A) ¹H NMR spectra [magnification of the H-C(2) and H-C(8) region] showing the extent of adenosine degradation at pH 3.5 and 60 °C. (B) Same as panel A at pH 7.1 and 90 °C. (C) Plot of the percentage of oligonucleotide 5a as a function of time, following incubation at either pH 3.5 and 60 °C or pH 7.1 and 90 °C, in the presence or absence of Mg²⁺. (D) Average (±standard deviation) hydrolysis rate constants (k_obs) and phosphodiester bond half-lives (t_1/2), as calculated from panel C.