Short oligomeric chains of C-glycosyl β-D-arabinofuranose configured tetrahydrofuran amino acids (where the C-2 and C-5 substituents of the tetrahydrofuran ring are cis to each other) exhibit a well-defined repeating turn secondary structure stabilised by (i, i
− 2) inter-residue hydrogen bonds. This is in contrast to the epimeric α-D-arabinofuranose oligomer (where the C-2 and C-5 substituents of the tetrahydrofuran ring are trans to each other) in which there is no indication of any secondary structure in solution.
C-糖基 β-D-阿拉伯
呋喃糖配置的
四氢呋喃氨基酸的短寡聚链(其中
四氢呋喃环的 C-2 和 C-5 取代基彼此顺式)表现出明确的重复转角二级结构,通过(i , 我
− 2) 残基间氢键。这与差向异构
α-D-阿拉伯呋喃糖低聚物(其中
四氢呋喃环的 C-2 和 C-5 取代基彼此互为反式)相反,后者在溶液中没有任何二级结构的迹象。