The potent anticancer compound ecteinascidin-743 (ET-743) as its 2-propanol disolvate.

Single crystals of the title compound, C(39)H(43)N(3)O(11)S.2C(3)H(8)O, have been obtained from 2-propanol/water solutions. ET-743 belongs to the group of ecteinascidins (ETs), which is a family of novel marine tetrahydroisoquinoline derivatives characterized by a monobridged pentacyclic skeleton. Three large principal planar groups are observed in the three-dimensional structure of the ET-743 molecule, corresponding to three aromatic units which are nearly perpendicular to each other. In the crystal, the methoxy group on the large fused ring system adopts an anti conformation with respect to the S atom, thus presenting the same conformation as that found in solution.