Nhat Quang Nguyen Trung, Peter Strazewski,*
Martin Olsson, Måns Ehrenberg
Nucleosides, Nucleotides and Nucleic Acids 2001, 20 (4-7), 383-384.

The conformational space of nascent peptide-accepting 3'-aminoacyl ribonucleos(t)ides:
1H NMR data and ab initio calculations of puromycin and some synthetic analogs
  New puromycin analogs were synthesised and tested for in vitro peptide release activity. pH- and T-dependent 1H NMR spectra in aqueous buffer let us gain insight into the conformational preferences of 3'-aminoacylamino-3'-deoxyadenosine (3'-aa-NH-3'-dA) derivatives. The experimental data was supplemented with a systematic ab initio study on 8 conformers of 3'-Ala-NH-3'-dA and on related 3'-amide and 3'-ester variants including 5'-O- and/or 2'-O-methyl, 5'-O-methylphosphate, and 2'-fluoro groups (42-49 atoms, 24-29 non-H, calculated with Gaussian 98 using HF, B3LYP, MP2 methods and 6-31G**, 6-31+G** and 6-311++G** basis sets).  
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