The title compound, C57H85N9O9·2C2H3N [systematic name: cyclo-(prolyl-prolyl-phenylalanyl-phenylalanyl-leucyl-isoleucyl-isoleucylleucyl-valyl) acetonitrile disolvate; synonym: cyclolinopeptide acetonitrile disolvate], is a polypeptide with nine amino acids, viz. NαC-(Pro1–Pro2–Phe3–Phe4–Leu5–Ile6–Ile7–Leu8–Val9). It was extracted from flaxseed oil and crystallized from acetonitrile as a disolvate. In the title molecule, there are four intramolecular N—H...O hydrogen bonds. One of the two acetonitrile molecules is hydrogen bonded to Phe3 via an N—H...N hydrogen bond, while the second acetonitrile molecule is located at the other side of the peptide ring and is linked to the title molecule by a C—H...N hydrogen bond. In the crystal, molecules are linked by N—H...O hydrogen bonds, forming chains along the a-axis direction. The chains are linked by C—H...O hydrogen bonds, forming undulating layers parallel to the ac plane.
