1. Contribution from the Magnetic Resonance Center (CERM), University of Florence, Via L. Sacconi 6, 50019 Sesto Fiorentino, Italy, Department of Chemistry, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Italy, Department of Agricultural Biotechnology, University of Florence, Via Maragliano, 75-77, 50144 Florence, Italy, ProtEra S.r.l., Via delle Idee, 22, 50019 Sesto Fiorentino, Italy, and Department of Organic Chemistry, University of Florence, Via della Lastruccia 13, 50019 Sesto...