The desoxazoline asidiacyclamide analogue cyclo(Gly–Thr–D-Val–Thz–Ile–Thr–D-Val–Thz) acetonitrile monosolvate

Abstract

The title peptide [systematic name: 4-(butan-2-yl)-7,20-bis(1-hydroxyethyl)-10,23-bis(propan-2-yl)-12,25-dithia-3,6,9,16,19,22,27,28-octaazatricyclo[22.2.1.111,14]octacosa-1(26),11(28),13,24(27)-tetraene-2,5,8,15,18,21-hexone acetonitrile monosolvate], C32H48N8O8S2·CH3CN, an analogue of ascidiacyclamide (ASC) [cyclo(–Ile–Oxz–D-Val–Thz–)2], lies about a twofold rotation axis, so that the glycine (Gly) and isoleucine (Ile) residues are each disordered over two sites with equal occupancies. The acetonitrile molecule is also located on a twofold axis passing through the C and N atoms. In the peptide, the thiazole rings are faced to each other with a dihedral angle of 9.63 (15)° and intramolecular N—H...O and O—H...O hydrogen bonds are observed. A bifurcated N—H...(O,O) hydrogen bond links the peptide molecules into a layer parallel to the ab plane.