Cyclo-linopeptide B methanol tris-olvate

Acta Crystallogr Sect E Struct Rep Online. 2012 Jan;68(Pt 1):o50-1. doi: 10.1107/S1600536811051488. Epub 2011 Dec 7.

Abstract

The title compound, C(56)H(83)N(9)O(9)S·3CH(3)OH, is a methanol tris-olvate of the cyclo-linopeptide cyclo(Met(1)-Leu(2)-Ile(3)-Pro(4)-Pro(5)-Phe(6)-Phe(7)-Val(8)-Ile(9)) (henceforth referred to as CLP-B), which was isolated from flaxseed oil. All the amino acid residues are in an l-configuration based on the CORN rule. The cyclic nona-peptide exhibits eight trans peptide bonds and one cis peptide bond observed between the two proline residues. The conformation is stabilized by an α-turn and two consecutive β-turns each containing a N-H⋯O hydrogen bond between the carbonyl group O atom of the first residue and the amide group H atom of the fourth (α-turn) or the third residue (β-turns), repectively. In the crystal, the components of the structure are linked by N-H⋯O and O-H⋯O hydrogen bonds into chains parallel to the a axis.