Konformationsanalysen von Modell‐Tripeptiden: Der Einfluss von α,α‐disubstituierten α‐Aminosäuren auf die Sekundärstruktur. Teil II. Röntgenstrukturanalyse und Konformationsenergie‐Berechnungen

Conformational Analysis of Tripeptide Models: The Influence of α,α‐disubstituted α‐Amino Acids on the Secondary Structure. X‐Ray Analysis and Conformational Energy Calculations The X‐ray analysis of tripeptide Z‐Ile‐Val(2‐Me)‐benzocaine (1f) reveals the presence of a type‐III β‐turn. Moreover, MMP2 calculations on tripeptides, e.g. Z‐Ile‐Aib‐benzocaine (1c), Z‐Ile‐D‐Val(2‐Me)‐benzocaine (1g), Z‐Ile‐Gly(2,2‐Pr2)‐benzocaine (1h), Z‐Ile‐Gly‐benzocaine (1a), and 1f, fit well into the frame of NMR and CD investigations. They allow considerations on the relative stability of different types of β‐turns depending on the peptide sequence, e.g. the kind of α,α‐disubstituted amino‐acid moieties.