Structural Elucidation And Toxic Effects Of Gossypol Degradation Products In Cottonseed Oil

Objective:The national standard of free gossypol in cottonseed oil content detection is exist,but because of free gossypol in cottonseed oil can easily degrade at room temperature,so this method can not reflect the detoxification of cottonseed oil accurately.We will study the relationship between the free gossypol and degradation products,identificate chemical structure of main gossypol degradation products.The reproductive toxicity of free gossypol degradation products was investigated by in vivo and in vitro toxicity experiments,and establish a method for the determination of the degradation products of main free gossypol in cottonseed oil.Methods:1.The cottonseed oil samples were extracted by hexane solvent extraction method.HPLC was used to determine the linear relationship between free gossypol and degradation products.2.C18 column and semi preparative high performance liquid chromatography(HPLC)were used to prepare the free gossypol degradation products.3.LC-FTICR-MS was used to identify the chemical structure of free gossypol degradation products.4.In vivo and in vitro toxicity of free gossypol degradation products were studied by GC-2 mouse spermatocyte cytotoxicity test and mouse sperm aberration test.5.Establish a method for the determination of the content of free gossypol degradation products,and determine the content of the main free gossypol degradation products in 24 batches of cottonseed oil.Results:1.The linear relationship between free gossypol and degradation products was Y=-3.00674395X+2058258982,r=0.9900.2.The main degradation products of free gossypol m/z was 573.25033,the molecular formula is C34H37O8,its structure identified as tetramethoxyl gossypol.3.The application of SPSS Statistics 17 software.the half inhibitory concentration of main free gossypol degradation products on mouse GC-2 spermatocytes was 6.554g/mL.The results of mouse sperm aberration test:Mouse sperm deformity rate in blank group was 1.1±0.42%,abnormal rate of positive group mouse sperm was 8.2 ±0.31%,the high dose group of mice sperm malformation rate was 4.4±0.51%,the middle dose group of mice sperm abnormality rate was 3±0.33%,the low dose group of mice sperm malformation rate was 1.8 ± 0.44%.The test method of experimental data processing,the positive group and the control group of sperm deformity rate compared to P<0.05,there was significant difference between high and low,and in the experimental group and the control group of sperm deformity rate compared to P<0.05,there was significant difference.4.The 24 batches of cotton seed oil samples were tested,and the results showed that the main free gossypol degradation products were detected in 20 batches of cottonseed oil,the content of which was from 0.139 to 0.912 g/mL.Conclusion:Determine the main free gossypol degradation products content in cottonseed oil to reflect the toxicity of removing free gossypol,this method is scientific and effective for the detection of the production and regulation of cottonseed oil in Xinjiang area.