Study On Subcritical Extraction And Antioxidant Activity Of Gossypol

In order to solve the problems of instability and difficult separation and purification in the current extraction of gossypol,cotton seed kernel was used as the raw material,and subcritical technology was used as the extraction method to study the effects of different influencing factors on subcritical extraction of free gossypol.The orthogonal experiment method was used to optimize the gossypol extraction process.The phenanthroline method and the pyrogallol auto-oxidation method were used to investigate the oxidation resistance of gossypol,and the effect of Fe²⁺ on the interaction between gossypol and DNA was studied.The main conclusions are as follows:The subcritical extraction method was used to optimize the extraction process of gossypol in cottonseed kernels,and the effects of temperature,time,frequency and material-liquid ratio on subcritical extraction efficiency were explored.The L9?34?orthogonal experiment proved The best extraction process for critical experiments.The results show that the sample pretreatment method is crushed through a 40-mesh sieve rolling embryo,temperature 20?,extraction time 40 min,extraction times 4 times,and the maximum extraction rate is 68.9% when the ratio of material to liquid is 1:14.The scavenging rate of gossypol to hydroxyl radicals and superoxide anion radicals was studied by phenanthroline method and pyrogallol auto-oxidation method.The results show that gossypol has the ability to scavenge hydroxyl radicals and superoxide anion radicals,and the scavenging ability of hydroxyl radicals and superoxide anion radicals gradually increases with the increase of gossypol concentration.When the scavenging rate of radical and superoxide anion radicals is 50%,the concentration of gossypol for scavenging hydroxyl radicals and superoxide anion radicals is3.5×10-4mol/L and 10.4×10-4mol/L,respectively,indicating that gossypol scavenging the ability of hydroxyl radicals is stronger than the ability to remove superoxide anion radicals.In the Tris-HCl buffer solution at p H=7.4,the interaction between gossypol and DNA and the effect of Fe²⁺ were studied using fluorescence spectroscopy and ultraviolet-visible spectroscopy.The UV results showed that the addition of Fe²⁺ weakened the absorption peak intensity of gossypol-DNA system and shifted the maximum absorption wavelength to red,indicating that Fe²⁺ participated in the process of gossypol and DNA;fluorescence experiments showed that gossypol has an effect on DNA-BR system.The fluorescence quenching is dynamic quenching.The addition of Fe²⁺enhances the fluorescence quenching of gossypol to the DNA-BR system,but does not change the quenching type and the action type,but increases the binding constant of the action of gossypol and DNA.And the number of binding sites shows that Fe²⁺ has a synergistic effect on the binding between gossypol and DNA.