Gossypol: high-performance liquid chromatographic analysis and stability in various solvents [in roots, stems, and seeds of cotton plants, toxicity]

An improved high performance liquid chromatography (HPLC) method of gossypol analysis was developed and compared with the current spectrophotometric method. Gossypol was determined in four samples of cottonseeds ofGossypium hirsutum with varying contents of gossypol, as well as in the stems and roots ofG. arboreum andG. thurber. The roots of both species each contained equally high amounts of gossypol, while the stems of each species varied in content. Those ofG. thurber contained slightly higher amounts of gossypol than those ofG. arboreum. Among the seeds studied, the glanded cottonseeds contained the highest concentration of gossypol, followed by low gossypol seeds, then glandless cottonseeds, and finally the roasted glandless cottonseeds. The stability of gossypol was studied in five solvents at six different storage temperatures. Both the type of solvent and the temperature were found to affect the rate of decomposition of gossypol. In all the solvents studied, gossypol was found to be highly unstable at 37 C and at room temperature, while its stability increased as the storage temperature decreased. At all temperatures, depending on the solvent used, the rate of decomposition increased in the following order: acetone < acetonitrile < chloroform < ethanol < methanol. Although the decomposition products of gossypol were not identified, their formation was found to be dependent on the solvent used.