1367370-60-2

Upstream product

• 1161-13-3 N-Cbz-L-Phe 
• 92844-95-6 H-(Aib)4-O-t-Bu 
• 1187839-12-8 Cbz(L-Phe)Aib₄OH 
• 1187839-07-1 Cbz(L-Phe)(α-aminoisobutyric acid₎₄OtBu 
• 1187839-02-6 N₃(α-aminoisobutyric acid)₄OtBu 

Downstream Products

• 1367370-30-6 C₅₇H₈₆N₁₂O₁₃ 
• 1367370-32-8 C₅₈H₈₈N₁₂O₁₃ 
• 1367370-34-0 C₅₇H₈₆N₁₂O₁₄ 
• 1367370-40-8 Cbz-L-Phe-Aib₄-Gly-Aib₄-Gly-NH₂ 
• 1367370-41-9 Cbz-L-Phe-Aib4-βAla-Aib4-Gly-NH2 
• 1367370-43-1 Cbz-L-Phe-Aib₄-Gly-Gly-Aib₄-Gly-NH₂ 

Relevant academic research and scientific papers

The N-terminal nonapeptide of cephaibols A and C: A naturally occurring example of mismatched helical screw-sense control

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.

Chemical communication: Conductors and insulators of screw-sense preference between helical oligo(aminoisobutyric acid) domains

1H NMR studies quantify the abilities of achiral amino acids to communicate a left-handed screw-sense preference from one helical Aib 4 domain to another: certain quaternary amino acids (e.g. Ac 6c) act as effective conductors of conformational preference while others (e.g. diphenylglycine) acts as insulators.