X-ray structural investigation of gossypol and its derivatives XXIX. Molecular and crystal structure of a complex of gossypolic acid lactone with acetic acid

The lactone of gossypolic acid, obtained by the demethylation of the tetramethyl ether of gossypolic acid, forms with acetic acid a stable complex having the 14 composition. The crystallographic parameters of single crystals are as follows:a=20.251(2) Å, b=12.028(3) Å, c=15.934(4) Å, V=3881.2(2.3) ų,Z=4, D_calc=1.32 g/cm³, sp. gr. Pbcn. The molecule is characterized by considerable strain because of the formation of the five-membered lactone ring the atoms of which are coplanar with the atoms of the naphthyl fragment. Unlike the clathrates of racemic gossypol and dianilinegossypol, the gossypolic acid lactone — acetic acid comples does not belong to the type of clathrate inclusion compounds.A. S. Sadykov Institute of Bioorganic Chemistry, Academy of Sciences of the Republic of Uzbekistan, Tashkent, Ul. Akad. Kh. Abdullaeva, 83. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 458–463, July–August, 1999.