TY - JOUR
T1 - Crystal-state structures of Boc-Pro-Leu-Gly-NH2 hemihydrate and two lactam-restricted analogues
AU - Valle, Giovanni
AU - Crisma, Marco
AU - Toniolo, Claudio
AU - Yu, Kuo Long
AU - Johnson, Rodney L.
PY - 1989
Y1 - 1989
N2 - A crystal-state structural analysis of Boc-Pro-Leu-Gly-NH2 (2a) hemihydrate and two conformationally restricted analogues that incorporate a γ- or δ-lactam modification at the -Leu-Gly- sequence, (3) and (4) respectively, has been performed by X-ray diffraction. In all three compounds the conformation of the tertiary amide group of the Nα-protecting urethane moiety is cis and the prolyl residue is semi-extended. The basic conformational feature of the published structure of H-Pro-Leu-Gly-NH2 (1), the ten-membered ring type-II β-bend structure at the C-terminus, is preserved in the Nα-butyloxycarbonyl derivative (2a). However, the γ- and δ-lactam modifications induce drastic changes in the backbone torsion angles of the -Leu-Gly- sequence, eventually promoting the onset of extended conformations.
AB - A crystal-state structural analysis of Boc-Pro-Leu-Gly-NH2 (2a) hemihydrate and two conformationally restricted analogues that incorporate a γ- or δ-lactam modification at the -Leu-Gly- sequence, (3) and (4) respectively, has been performed by X-ray diffraction. In all three compounds the conformation of the tertiary amide group of the Nα-protecting urethane moiety is cis and the prolyl residue is semi-extended. The basic conformational feature of the published structure of H-Pro-Leu-Gly-NH2 (1), the ten-membered ring type-II β-bend structure at the C-terminus, is preserved in the Nα-butyloxycarbonyl derivative (2a). However, the γ- and δ-lactam modifications induce drastic changes in the backbone torsion angles of the -Leu-Gly- sequence, eventually promoting the onset of extended conformations.
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U2 - 10.1039/p29890000083
DO - 10.1039/p29890000083
M3 - Article
AN - SCOPUS:0010557259
SN - 1472-779X
SP - 83
EP - 87
JO - Journal of the Chemical Society, Perkin Transactions 2
JF - Journal of the Chemical Society, Perkin Transactions 2
IS - 1
ER -