Vibrational spectra of N-acetylglycine oligomers Part 2.—Raman scattering study of selectively C-deuteriated oligomers with polyglycine I- and II-type structures
作者:Hideki Etori、Keijiro Taga、Hirofumi Okabayashi、Kunihiro Ohshima
DOI:10.1039/a605741a
日期:——
Selectively C-deuteriated N-acetylglycine trimer and
tetramer acid types have been synthesized, and their two crystalline
modifications, solid-A and solid-B [which correspond in structure to
polyglycine (PG) II and I, respectively] have been prepared. Raman
scattering spectra have been measured for a series of these glycine
oligomers, and the CH
2
- and CD
2
-characteristic
modes have been investigated in detail. Assignment of the
CH
2
-characteristic bands to each CH
2
group in
the oligomers has been carried out successfully. In particular, the
results obtained from the CD
2
stretch region show that N-
and C-terminal glycine residues for the PGI- and PGII-type trimers and
tetramers are all in very similar environments and that the glycine
residues which are sandwiched between the two terminal residues are
also in a similar environment for both the trimers and the tetramers.
选择性C-重氘化的N-乙酰甘氨酸三聚体和四聚体酸类型已被合成,且其两种晶体改型,固体-A和固体-B(分别对应于聚甘氨酸(PG)II和I的结构)已被制备。对一系列这些甘氨酸低聚物进行了拉曼散射谱测量,并详细研究了CH₂和CD₂的特征模式。成功地将CH₂特征带分配给低聚物中的每个CH₂基团。特别是在CD₂伸缩区域获得的结果表明,PGI型和PGII型三聚体及四聚体的N-末端和C-末端甘氨酸残基都处于非常相似的环境中,并且夹在两个末端残基之间的甘氨酸残基在三聚体和四聚体中也处于相似的环境中。