Organic Chemistry Division III, CSIR-Indian Institute of Chemical Technology, Hyderabad, 500607, India.
Org Biomol Chem. 2011 Dec 7;9(23):8102-11. doi: 10.1039/c1ob06279d. Epub 2011 Oct 19.
A new β-amino acid, trans-3-aminopyran-2-carboxylic acid (APyC), was designed and synthesized from (R)-glyceraldehyde derivative and used in the synthesis of α/β-peptides in a 1 : 1 alternating pattern with d-Ala. The presence of oxygen atom at the Cβ(2)-position in APyC was envisaged to provide opportunity for additional interaction. These hybrid peptides have shown the presence of 9/11-helix through extensive NMR and MD studies. The amide protons of d-Ala, in addition to participating in 9-mr H-bonding with CO of succeeding β-residue, were also involved in additional electrostatic interaction with pyran ring oxygen of preceding β-residue, which facilitated further stabilization to the 9/11-mixed helix. The study thus results in a new 'motif' for a 9/11-helix, and the first example from a cyclic β-amino acid.
一种新型的β-氨基酸，反式-3-氨基吡喃-2-羧酸（APyC），由（R）-甘油醛衍生物设计并合成，用于与 d-Ala 以 1:1 交替模式合成α/β-肽。APyC 中 Cβ(2)-位的氧原子预计会提供额外相互作用的机会。通过广泛的 NMR 和 MD 研究，这些杂合肽显示出存在 9/11-螺旋。d-Ala 的酰胺质子除了与后续β-残基的 CO 参与 9-mr H-键合外，还与前一个β-残基的吡喃环氧参与额外的静电相互作用，这有助于进一步稳定 9/11-混合螺旋。因此，该研究为 9/11-螺旋提供了一个新的“基序”，这也是第一个来自环状β-氨基酸的例子。
