Abstract
FK228 [systematic name: (1S,4S,7Z,10S,16E,21R)-7-ethyl-idene-4,21-di(propan-2-yl)-2-oxa-12,13-dithia-5,8,20,23-tetra-za--bicyclo[8.7.6]tricos-16-ene-3,6,9,19,22-pentone], C(24)H(36)N(4)O(6)S(2), also known as FR901228, depsipeptide, NSC 630176, romidepsin, and marketed as Istodax by Celgene Corporation, is crystallized from ethyl acetate in P2(1) as compared to the absolute configuration of FK228, first crystallized from methanol in P2(1)2(1)2(1) [Shigematsu et al. (1994 ▶). J. Anti-biot.47, 311-314]. A slight difference is observed between the absolute configuration of FK228 and the present structure. The molecular structure is stabilized by intramolecular N-H⋯O hydrogen bonds. In the crystal, molecules are linked via N-H⋯O hydrogen bonds.