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. 1.1 11,14]octacosa-1(26),-11(28),13,24(27)-tetraene-2,5,8,15,18,21- hexone acetonitrile monosolvate], C 32H 48N 8O 8S 2·CH 3CN, 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.