1187839-12-8Relevant articles and documents
The N-terminal nonapeptide of cephaibols A and C: A naturally occurring example of mismatched helical screw-sense control
Orcel, Ugo,De Poli, Matteo,De Zotti, Marta,Clayden, Jonathan
, p. 16357 - 16365 (2013/12/04)
The N-terminal nonapeptide domain of the fungal nonribosomal peptide antibiotics cephaibol A and cephaibol C (AcPheAib4LeuIvaGly- Aib) is reported to adopt a right-handed helical conformation in the crystalline state. However, this conformation is at odds with the left-handed helicity observed in solution in related synthetic oligomers capped with Ac-L-PheAib4 fragments. We report the synthesis of four diastereoisomers of the cephaibol N-terminal nonapeptide, and show by NMR and CD spectroscopy that the peptide containing the chiral amino acids Phe and Leu in the naturally occurring relative configuration exists in solution as an interconverting mixture of helical screw-sense conformers. In contrast, the nonapeptide containing the unnatural relative configuration at Phe and Leu adopts a single, stable helical screw-sense, which is left handed when the N-terminal Phe residue is L and right-handed when the N-terminal Phe residue is D.
Quantifying end-to-end conformational communication of chirality through an achiral peptide chain
Clayden, Jonathan,Castellanos, Alejandro,Sola, Jordi,Morris, Gareth A.
supporting information; experimental part, p. 5962 - 5965 (2009/12/08)
Successful communication: Two diastereotopic protons more than 60 bonds from the nearest chiral center appear as an AB system, showing that the intervening structure is a well-ordered helix. Decay of anisochronicity quantifies the linear persistence of a
