{'fraction_non_alphanumeric': 0.04275286757038582, 'fraction_numerical': 0.021897810218978103, 'mean_word_length': 5.114649681528663, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Conformations of the Nucleoside Analogs Formycin, 2-Azaadenosine, and Nebularine in Solution

The ribose conformations of formycin, 2-azaadenosine, nebularine, 8-bromoinosine, and 8-bromo- xanthosine have been studied using proton magnetic resonance in ND3 solutions, in D2O solutions, and in pyridine solutions. The temperature was varied between - 60 °C and +40 °C in ND3 and between +10 °C and +60 °C in D2O solutions. In solution, 2-azaadenosine and nebularine have a conformational behaviour similar to that of the common purine (β) ribosides. This is in agreement with the conformations observed in the solid state. The conformations of formycin and formycin B have strong analogies with those of the 8-bromopurineribosides and differ significantly from those of the 8-azapurineribosides since they adopt preferentially the syn-S-g+ conformation. This conformation is very probably stabilized by an intramolecular hydrogen bond between O (5′) and N (3).