Crystal and molecular structure of the centrosymmetric meso‐valinomycin analogue—cyclo (D‐Val‐D‐Hyi‐D‐Val‐L‐Hyi‐L‐Val‐D‐Hyi‐L‐Val‐L‐Hyi‐L‐Val‐D‐Hyi‐L‐Val‐L‐Hyi) (C₆₀H₁₀₂N₆O₁₈)

The crystal structure of cyclo (D‐Val‐D‐Hyi‐D‐Val‐L‐Hyi‐L‐Val‐D‐Hyi‐L‐Val‐L‐Hyi‐L‐Val‐D‐Hyi‐L‐Val‐L‐Hyi)‐2H₂O has been solved by x‐ray direct methods. The crystals (grown from a mixture of octane / CH₂C₁₂) are an orthorhombic, centrosymmetric space group Pbca, cell parameters a = 11.458(2). b = 25.613(3). c = 23.691(3) Å. Z = 4; therefore the molecule lies on a center of inversion in the cell. The atomic coordinates for the C, N, and O atoms were refined in the anisotropic thermal motion approximation (allowing for II‐atom contribution to F_cal) to a standard R‐ factor value of 0.081. In contrast to meso‐valinomycin, the analogue under study does not adopt an octahedral cage bracelet conformation. It has an unusual centrosymmetric elongated form with two type II terminal β‐bends formed by NHCO 4 → 1 type intramolecular H bonds. Two symmetry‐related water molecules reside in the elongated molecular cavity of the centrosymmetric depsipeptide ring. © 1995 John Wiley & Sons, Inc.