Induced Axial Chirality in the Biphenyl Core of the Proatropoisomeric, Cα-Tetrasubstituted α-Amino Acid Residue Bip in Peptides
作者:Jean-Paul Mazaleyrat、Karen Wright、Anne Gaucher、Nathalie Toulemonde、Laurence Dutot、Michel Wakselman、Quirinus B. Broxterman、Bernard Kaptein、Simona Oancea、Cristina Peggion、Marco Crisma、Fernando Formaggio、Claudio Toniolo
DOI:10.1002/chem.200500187
日期:2005.11.18
An induced axial chirality in the biphenyl core of the 2',1':1,2;1'',2'':3,4-dibenzcyclohepta-1,3-diene-6-amino-6-carboxylic acid (Bip) residue, a conformationally labile, atropoisomeric, C(alpha)-tetrasubstituted alpha-amino acid, was observed by CD and (1)H NMR spectroscopic techniques in the linear dipeptides Boc-Bip-Xaa*-OMe where Boc=tert-butoxycarbonyl, OMe=methoxy, and Xaa*=D- and/or L-Ala,
2',1':1,2; 1'',2'':3,4-dibenzcyclohepta-1,3-diene-6-amino-6-acid(Bip)的联苯核中诱导的轴向手性CD和(1)H NMR光谱技术在线性二肽Boc-Bip-Xaa * -OMe中观察到)残基,这是一种构象不稳定的阻转异构体Cα-四取代的α-氨基酸,其中Boc =叔丁氧羰基,OMe =甲氧基,并且Xaa * = D-和/或L-Ala,-Val,-Leu,-Phe,-(alphaMe)Val和-(alphaMe)Leu。在同分异构的二肽Boc-Xaa * -Bip-OMe中,手性诱导显着降低,Xaa *残基位于Bip的N端,以及在环状二肽环-[Bip-L-Ala]中。在溶液中获得的结果通过对Boc-(R)-Bip-D-Ala-OMe的晶体样品进行X射线衍射分析得到证实。