The Cyclo-β-Tetrapeptide (β-HPhe-β-HThr-β-HLys-β-HTrp): Synthesis, NMR Structure in Methanol Solution, and Affinity for Human Somatostatin Receptors
作者:Karl Gademann、Martin Ernst、Dieter Seebach、Daniel Hoyer
DOI:10.1002/(sici)1522-2675(20000119)83:1<16::aid-hlca16>3.0.co;2-3
日期:2000.1.19
Z)-OMe. The (N-Me)-β-HThr-(N-Me)-β-HPhe analog was also prepd. C- and N-terminal deprotection and cyclization through the pentafluorophenyl ester gave the insol. beta-tetrapeptide with protected Thr and Lys side chains. Solubilization and debenzylation could only be effected in LiCl-contg. THF (ca. 10% yield; with ca. 55% recovery). HPLC Purifn. provided a sample of the title compd., the structure
环(β-HAla)4 的已知固态结构用于模拟环-β-四肽(β-HPhe-β-HThr-β-HLys-β-HTrp)的结构,作为一种前瞻性的生长抑素模拟物。合成开始于 N-保护的天然氨基酸 Boc-Phe-OH、Boc-Trp-OH、Boc-Lys(2-Cl-Z)-OH (2-Cl-Z = o-chlorobenzyloxycarbonyl) 和 Boc- Thr(OBn)-OH (Bn = 苄基),与相应的 β-氨基酸衍生物同源。并与 β-四肽 Boc-β-HTrp-β-HPhe-β-HThr(OBn)-β-HLys(2-Cl-Z)-OMe 偶联。还制备了 (N-Me)-β-HThr-(N-Me)-β-HPhe 类似物。通过五氟苯基酯的C-和N-末端去保护和环化得到insol。具有受保护的 Thr 和 Lys 侧链的 β-四肽。增溶和脱苄基只能在 LiCl-contg 中进行。THF(产率约