By a chemo-enzymatic approach we performed a large-scale, stereoselective synthesis of the Cα-methylated α-hydroxy acid L-(αMe)Hyv. We also prepared model depsipeptides based on this sterically demanding residue in combination with the α-amino acids L-Ala, L-Val, and Aib. From solution (FT-IR absorption and 1H NMR) and crystal-state (X-ray diffraction) conformational analyses we found that L-(αMe)Hyv forces depsipeptides to fold into right-handed β-turn/helical structures by analogy with the reported propensity of L-(αMe)Val, its α-amino acid counterpart.
通过
化学酶法,我们进行了Cα-甲基化α-羟基酸L-(αMe)Hyv 的大规模、立体选择性合成。我们还根据这种空间要求残基与
α-氨基酸L-Ala、L-Val 和Aib 的组合制备了缩
酚肽模型。通过溶液(FT-IR 吸收和 1H NMR)和晶态(X 射线衍射)构象分析,我们发现 L-(αMe)Hyv 迫使缩
酚肽通过类比折叠成右手β-转/螺旋结构与报道的L-(αMe)Val(其
α-氨基酸对应物)的倾向有关。