采用HPLC-MS/MS监控反应,合成了微囊藻毒素RR的谷胱甘肽和半胱氨酸代谢物(MC-RR-GSH及MC-RR-Cys)。该产物经AccuBOND C18固相萃取小柱纯化后,纯度大于95%(HPLC检测)。结果表明,合成反应的最佳时间为60 min。在SPE洗脱过程中,采用纯水淋洗,1%甲酸-90%甲醇洗脱时,MC-RR-GSH和MC-RR-Cys的平均回收率可达86.4%±1.5%和90.2%±2.8%。运用ESI-HPLC-MS/MS对以上产物进行一级及二级质谱扫描。两种产物的一级质谱电离均以[M+2H]2+为基峰,对应的质荷比(m/z)分别为673.6和580.5。以MC-RR-GSH和MC-RR-Cys一级质谱图中丰度最高的双电荷离子为母离子进行二级质谱扫描,对应的子离子对为m/z 609.0/536.9和519.4/520.8,由上述裂解碎片推断合成的产物为MC-RR-GSH和MC-RR-Cys。以合成产物为标准品,测定出太湖鲤鱼肾脏中MC-RR-GSH,MC-RR-Cys和MC-RR的含量(干重)分别为未检出,1.587 5,0.001 5 μg?kg-1。本文合成的高纯度代谢产物,可作为相关研究中非商品化的标准对照品,代谢产物的质谱裂解碎片亦可为环境中微囊藻毒素MC-RR的GSH/Cys代谢途径分析提供参考。
GSH and Cys metabolites of microcystin-RR(MC-RR) were synthesized chemically by the monitoring of high liquid chromatography-electrospray ionization ion trap mass spectrometry(HPLC-ESI-ITMS).Based on the enrichment and purification of AccuBOND C18 solid phase extraction(SPE),the purity of these s-conjugates were higher than 95% by HPLC.In this study,the optimum reaction time and SPE cartridges treatment procedure were also studied,and 60 min was obtained as the optimal time for the s-conjugates synthesis.Extraction parameters including proportions of methanol in elution and washing solution were optimized,and the best mean recoveries were obtained by 90% methanol in elution after water washing,and their recoveries were in the ranges of 86.4%±1.5% and 90.2%±2.8% for GSH conjugates of MC-RR(MC-RR-GSH) and Cys conjugates of MC-RR(MC-RR-Cys),respectively.These metabolites were subsequently confirmed by high phase liquid chromatography-electrospray ionization ion trap mass spectrometry(HPLC-ESI-ITMS).The fragment ions of the metabolites of MC-RR were characterized,and the most aboundant ions for MC-RR-GSH and MC-RR-Cys were at m/z 673.6 and m/z 580.5,respectively,and these ions were further selected as precursor ion in MS/MS,while the product ions of these parent ions were at m/z 609.0/536.9 and 519.4/520.8,respectively.These purified metabolites were successfully applied as standard compounds in the quantification of MC-RR-GSH,MC-RR-Cys and MC-RR in the kidney of commom carp,and the contents(dry weight) were obtained at the levels of undetected(ND),1.587 5,0.001 5 μg?kg-1,respectively.Futhermore,these metabolites could be used as significant reference substances in various studies,and the cleavage rules of MC-RR-GSH and MC-RR-Cys could provide some metabolic mechanism of microcystin-RR.
微囊藻毒素RR微囊藻毒素RR谷胱甘肽结合产物微囊藻毒素RR半胱氨酸结合产物高效液相色谱-质谱联用
MC-RRMC-RR-GSHMC-RR-CysHPLC-MS/MS
0
Views
1165
下载量
2
CSCD
Publicity Resources
Related Articles
Related Author
Related Institution