Variance Analysis Of Isoflavones In GM Soybean And Non-GM Soybean

In this paper, genetically modified(GM) soybean and non-genetically modified (non-GM) soybean have been studied. A method assisting by ultrasonic has been developed to extract the isoflavones of soybean, and the method of high performance liquid chromatography electrospray ionization ion trap multistage mass spectrometry (HPLC-ESI-MSn)has been established to separate and identify the soybean isoflavones, which laid the foundation for soybean development of deep-stead and provided theoretical support for the safety research of GM soybean.The single factor experiment and orthogonal analysis method were used to optimize the extraction conditions, the best parameters were:solid-liquid ratio,1:40; extraction time, 50 min; ethanol concentration:70%; extraction temperature,30℃. the total isoflavones yield under this condition was 0.69%.In this study, the instrument parameters of high-performance liquid chromatographic and electrospray ionization mass spectrometry were optimized to separate and identity the soybean isoflavones. The column:ZORBAXSB-C18(2.1mm×150mm,3.5μm); column temperature:35℃; flow rate:0.2 mL/min; auto-injection volumue:10μL; mobile phase: acetonitrile (A) and water which containing 0.025% formic acid (pH 2.8) (B), gRDAient elution conditions:0～10min10%～20%A; 10-13min20%A; 13-20min20%～45%A; 20-25min45%-55%A; 25-30min55%～10%A and keeping 10min;diode array detector (PDA) scan wavelength:200-500 nm; mass spectrometry scan range in positive ion mode: 200-700; the normalized collision energy was 45% for the main peaks of MS2 and MS". Finally, we got the multi-stage pyrolysis law of soybean isoflavones.According to the fragmentation mechanism of standard materials, HPLC retention time and MS and MS" fragmentations, a total of 12 isoflavones had been identified. They were:Daidzein, Glycitein, Genistein, Daidzin, Glycitin, Genistin,6"-O-malonyldaidzin, 6"-O-malonylglycitin,6"-O-malonylgenistin,6"-O-acetyldaidzin,6"-O-acetylglycitin, 6"-O-a-cetylgenistin.The differences of isoflavones between GM soybean and non-GM soybean were compared in this study, and the result showed that:the content of total isoflavones in GM soy was less than its parent; and the relative contents of 12 kinds of isoflavones were different with its parent after genetically modified. In general, there were significant differences in content of soybean isoflavones between GM soybean and non-GM soybean.