INCLUSION COMPLEXES OF THE NATURAL PRODUCT GOSSYPOL - CRYSTAL-STRUCTURE OF THE 2-1 COMPLEX OF GOSSYPOL WITH AMYL ACRYLATE

The crystal structure of the 2: 1 inclusion complex of gossypol with amyl acrylate has been determined by X-ray structure analysis. The crystals of (C30H30O8)2″″C8H14O2 are triclinic, space group P {Mathematical expression}, a = 14.425(2), b = 15.519(1), c = 16.409(2) Å, α =97.89(1), β = 117.80(1), γ =67.01(1)° (reduced cell:a = 14.425(2), b = 15.519(2), c = 16.017(2)Å, α = 92.19(1), β = 115.01(l), γ =67.01(1)°], V = 2986.7(5) Å3, Z = 2, Dx = 1.31 g cm-3, μ(Cu Kα) = 7.40 cm-1, T = 292 K. The structure has been solved by direct methods and refined to the final R value of 0.059 for 5155 observed reflections. The gossypol molecules bonded via several hydrogen bonds form centrosymmetric tetramers. The two independent gossypol molecules, A and B, are related within the tetramer by a local noncrystallographic 2-fold axis. The host molecules in the crystal form cavities in which two guest molecules are placed. The ester molecule interacts via a pair of C-...H-O hydrogen bonds with two gossypol molecules of the same chirality and belonging to the same tetramer unit. The amyloxy group of the ester molecule shows a very large thermal motion. It adopts a non-extended conformation in which it can be fitted into the cavity formed by the host molecules. © 1990 Kluwer Academic Publishers.