STRUCTURE OF THE CRYSTALLINE [PHE(1), ALA(9)]ANTAMANIDE MOLECULES

The molecular structure of a [Phe1, Ala9]antamanide complex with four water molecules has been determined by X-ray analysis. The antamanide' s analogue, C64H74N10O10.4H2O, crystallizes in the space group P2(1)2( 1)2(1) with a = 15.909, b = 28.071 and c = 14.367 angstrom, Z = 4. The molecule contains a pseudo two-fold rotation axis and two intra-molec ular NH...O=C bonds of the 5 --> 1 type, its conformation being simila r to that of antamanide. There are inter-molecular H-bonds over the wa ter molecules in the structure.