Intramolecular Hydrogen Bonding and Conformation of Small Peptides: Variable-Temperature FTIR Study on <i>N</i>-Acetyl-<scp>l</scp>-Pro-<scp>l</scp>-Leu-Gly-NH<sub>2</sub> and Related Compounds
作者:Kenji Tonan、Shun-ichi Ikawa
DOI:10.1021/ja953380a
日期:1996.1.1
spectra of analogous amide compounds. From temperature dependence of the band intensities, it is concluded that the C-terminal amide group takes part in the hydrogen bonding in both hydrogen-bonded conformers. From comparison with spectra of N-trifluoroacetyl-l-Pro-l-Leu-Gly-NH2 and l-Pro-l-Leu-Gly-NH2, the 3290-cm-1 band has been assigned to a 13-membered ring with the hydrogen bond between NH of the C-terminal
已通过变温 FTIR 光谱检查了 CDCl3 溶液中三肽酰胺的分子内氢键和构象。N-乙酰基-1-Pro-1-Leu-Gly-NH2在NH伸缩区的吸收通过最小二乘拟合分解为一些组分带。3350 和 3290 cm-1 附近的两个宽带被分配给不同构象异构体中的分子内氢键合 NH 基团。通过参考类似酰胺化合物的光谱,其他相对尖锐的带被分配给三个不同酰胺基团的无氢键的 NH。从能带强度的温度依赖性得出结论,C-末端酰胺基团参与了两个氢键构象异构体的氢键。从与 N-三氟乙酰基-l-Pro-l-Leu-Gly-NH2 和 l-Pro-l-Leu-Gly-NH2 的光谱比较,3290-cm-1 谱带被指定为一个 13 元环,在 C 端酰胺基团的 NH 和 N 端乙酰基团的 CO 之间存在氢键。3350-...