Gossypol reactions

Solutions obtained for the analysis of other food ingredients had the greatest color development, i.e., false gossypol values, at pH 5 to 6. False gossypol reactions could not be eliminated by altering the pH of the reacting solutions in the AOCS (19) procedure. It is essential to be able to accurately determine the amount of an... 

Figure 12. Reaction of protein-bound gossypol with 3-amino-l-propanol in the presence of acetic acid in DMF solution (4)...

Figure 14. UV spectra of (A) gossypol-amino reaction mixture and (B) extract from aminopropanol treatment of water and salt-solution insoluble fraction of LCP cottonseed flour (4)...

The reaction of 17/ -estradiol (14) with cesium fluoroxysulfate and boron trifluoride-diethyl ether complex in acetonitrile gives the 2-fluoro and 4-fluoro isomers in a 1 1 ratio,17 while the reaction with the hexamethyl ether of gossypol fails under a variety of conditions.21... 

Wulff and co-workers observed that the oxidative dimerization of 147 can be accomplished extremely efficiently when it is melted in a sealed tube in the presence of air, to furnish the biaryl product 148, a precursor to the natural compound gossypol (149) (Scheme 35) [99]. The same reaction with iron(III) chloride gives low yields and a less clean product distribution. It is interesting to note that in the case of 3-phenyl-l-naphthol (150), the regioselectivity of the iron(III) chloride-mediated oxidation is completely different from that observed with 02 as the oxidant, with the para-para-coupled product 152 being favored. This air oxidation procedure is also applicable to phenanthrol units (e.g. 153 —> 154), giving similarly high yields. 

Jones (36) reviewed the natural antinutrients of cottonseed protein products— gossypol and the cyclopropenoic fatty acids (CPFA malvalic and sterculic acids). The CPFAs participate in forming the pink color complex in the Halphen reaction, a test specific for the admixture of cottonseed oil with other oils and fats. They also inhibit A9 desamrase, an enzyme that converts stearic acid into oleic acid, and thus increase hardness of fats from animals (e.g., pig backfat and lard) raised or finished on feedstuffs containing high levels of polyunsamrated oils like corn. Feed industry practice is to limit cottonseed lipids to no more than 0.1-0.2% in the diet of laying hens to avoid pink discoloration of egg whites and alterations of the vitelline membrane that cause pasty yolks. 

Gossypol is a polyphenolic aldehydic compound, and it has been studied for its versatile biological activities. Gossypol s biological activities are based on direct chemical reactions, the inhibition of enzymes, and the regulation of signal transduction pathways. However, due to its toxicity, the application of gossypol is sometimes limited. 

Cater, C. M. (1968). Studies on the reaction products of gossypol with amino acids, peptides, and proteins. Dissertation. Texas A M University, College Station, TX. 

Shirley, D. A., Brody, S. S., and Sheehan, W. C. (1957). Structure and reactions of gossypol. V. Methylapogossypol hexamethyl ether and 2, 3-dimethoxy-4-isopropyl-5-allyltoluene. 

Talipov, S.A. Manakov. A. Ibragimov, B.T. Lipkowski. J. Tiljakov, Z.G. Sorption of ammonia, methylamine and methanol by the P3 polymorph of gossypol. Synthesis of unsymmetric monoamine derivatives of gossypol by a solid-state reaction. J. Incl. Phenom. Mol. Recognit. Chem. 1997. 29. 33-39. 

Gdaniec, M. Crystal structure of the product of a condensation reaction of (+ —)-gossypol with R-(-i-)-l-phenylethylamine. Why do diastereoisomeric diaminogos-sypol cocrystallize J. Incl. Phenom. Mol. Recognit. Chem. 1994. 17, 365-376. 

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