Redetermined structure of gossypol (P3 polymorph).
An improved crystal structure of the title compound, C30H30O8 (systematic name: 1,1',6,6',7,7'-hexa-hydroxy-5,5'-diisopropyl-3,3'-dimeth-yl[2,2'-bi-naphthalene]-8,8'-dicarbaldehyde), was determined based on modern CCD data. Compared to the previous structure [Talipov et al. (1985). Khim. Prirod. Soedin. (Chem. Nat. Prod.), 6, 20-24], geometrical precision has been improved (typical C-C bond-distance s.u. = 0.002 Å in the present structure compared to 0.005 Å in the previous structure) and the locations of several H atoms have been corrected. The gossypol mol-ecules are in the aldehyde tautomeric form and the dihedral angle between the naphthyl fragments is 80.42 (4)°. Four intra-molecular O-H⋯O hydrogen bonds are formed. In the crystal, inversion dimers with graph-set motif R 2 (2)(20) are formed by pairs of O-H⋯O hydrogen bonds; another pair of O-H⋯O hydrogen bonds with the same graph-set motif links the dimers into [001] chains. The packing of such chains in the crystal leads to the formation of channels (diameter = 5-8 Å) propagating in the [101] direction. The channels presumably contain highly disordered solvent mol-ecules; their contribution to the scattering was removed with the SQUEEZE [Spek (2015). Acta Cryst. C71, 9-18] routine in PLATON and the stated mol-ecular mass, density etc., do not take them into account.
Institute of Biorganic Chemistry, Mirzo-Ulughbek Str. 83, Tashkent 100125, Uzbekistan.
Muhabbat
M
Honkeldieva
Institute of Biorganic Chemistry, Mirzo-Ulughbek Str. 83, Tashkent 100125, Uzbekistan.
Rishad
R
Kunafiev
Institute of Biorganic Chemistry, Mirzo-Ulughbek Str. 83, Tashkent 100125, Uzbekistan.
Hayrullo I
HI
Hamidov
crystal structure; gossypol; hydrogen bonding; polymorph; redetermination