Sequence and solution structure of cherimolacyclopeptides A and B, novel cyclooctapeptides from the seeds of Annona cherimola

A. Wélé (1) , C. Landon (2) , H. Labbé (2) , F. Vovelle (2) , Y. Zhang (1) , B. Bodo (1)

1 Laboratoire de chimie et biochimie des substances naturelles
2 CBM - Centre de biophysique moléculaire

Two new cyclooctapeptides, cherimolacyclopeptide A, cyclo(Pro1-Gln2-Thr3-Gly4-Met5-Leu6-Pro7-Ile8-) (1) and the related cherimolacyclopeptide B, cyclo(Pro1-Gln2-Thr3-Gly4-Mso5-Leu6-Pro7-Ile8-) (2), have been isolated from the methanol extract of the seeds of Annona cherimola Miller. The sequences were elucidated on the basis of the MS/MS fragmentation, using a Q-TOF mass spectrometer equipped with an ESI source, chemical degradation and extensive 2D-heteronuclear NMR. The three-dimensional solution structure of cherimolacyclopeptide A (1) determined by 1H NMR data and molecular modelling is characterised by the presence of two β turns and a new type of β-bulge.

Domaines: Biochimie [q-bio.BM]

A. Wélé, C. Landon, H. Labbé, F. Vovelle, Y. Zhang, et al.. Sequence and solution structure of cherimolacyclopeptides A and B, novel cyclooctapeptides from the seeds of Annona cherimola. Tetrahedron, 2004, 60 (2), pp.405-414. ⟨10.1016/j.tet.2003.11.026⟩. ⟨hal-00016015⟩