Selective Esterification of Gossypol by Copper Acetate in Acetonitrile-Spectroscopic Studies

Abstract Gossypol and its 1: 1 complexes with copper acetate in acetonitrile were studied by FTIR and UV-visible spectroscopy. With the complexation with Cu cation the tautomeric equilibrium of gossypol is completely shifted from the aldehyde-aldehyde to the lactol-lactol tautomer. The acidic character of O11H group in the gossypol-Cu complex led to the selective esterification of the lactol form of gossypol by the acetate group.

[1]  B. Marciniak,et al.  The tautomerization of gossypol as a function of the presence of Ni2+, Cu2+ or Zn2+ cations , 1992 .

[2]  B. Marciniak,et al.  UV-Visible Absorption Studies of Gossypol-Metal Cation Complexes in Acetonitrile Solution , 1991 .

[3]  B. Brzeziński,et al.  The structure of Gossypol as a function of the presence of HAuCl4 and of Be2+ ions , 1991 .

[4]  B. Brycki,et al.  1H AND 13C NMR Studies of Tetrabutylammonium Salts of Gossypol in Chloroform Solution , 1991 .

[5]  G. Schroeder,et al.  Spectroscopic and kinetic studies of the aldehyde–lactol tautomerization of gossypol in solution , 1991 .

[6]  J. Olejnik,et al.  Fourier transform infrared study on the identification of gossypol tautomers , 1990 .

[7]  J. Olejnik,et al.  1H NMR studies of gossypol and its complexes with some organic compounds , 1990 .

[8]  P. Dewick,et al.  Antifungal Antibiotics from Calcarisporium thermophilum: A New Source of 15-Azahomosterol Derivatives , 1990, Zeitschrift fur Naturforschung. C, Journal of biosciences.

[9]  B. Brzeziński,et al.  The influence of temperature on the proton polarizability of an intramolecular hydrogen-bonded system within the gossypol molecule , 1990 .

[10]  C. R. Howell,et al.  Spectral identification of the ketol tautomer of gossypol , 1973 .

[11]  R. Andersen,et al.  t-Butoxyberyllium halides and related compounds: the series X2Be3(OBut)4 , 1972 .

[12]  N. Mōri,et al.  Intramolecular Hydrogen Bonds. XIII. The Preferable Conformation of α-Hydroxy-carboxylic and o-Hydroxybenzoic Acids , 1969 .

[13]  N. Mōri,et al.  Intramolecular Hydrogen Bonds. XIV. Correlation of the Hydroxyl and the Carbonyl Frequencies of Methyl Salicylates with Hammett’s Substituent Constants , 1969 .

[14]  K. Nakamoto,et al.  Infrared Spectra of Aqueous Solutions. I. Metal Chelate Compounds of Amino Acids1 , 1961 .

[15]  J. D. Edwards,et al.  Gossypol, a pigment of cottonseed. , 1960, Chemical reviews.

[16]  F. Schoening,et al.  A new type of copper complex as found in the crystal structure of cupric acetate, Cu2(CH3COO)4.2H2O , 1953 .

[17]  F. Schoening,et al.  X-Ray Evidence for Metal-to-Metal Bonds in Cupric and Chromous Acetate , 1953, Nature.