Sinapine Detection And It's Biological Activity Investigation Using Surface Desorption Chemical Ionization Mass Spectrometry

Sinapine is a kind of quaternary ammonium alkaloids, a natural anti-oxidant of greatvalue and with a wide range of pharmacological activities such as anti-radiation,anti-aging, hypotensive, anti-inflammatory, anti-diarrheal, anti-androgen and so on, andcan be found in a variety of plants of the family Cruciferae. To develop an effective andsensitive method for fast detection of sinapine is, therefore, of considerable importance inresearch and practical fields such as agricultural production, pharmaceutical analysis andquality control, etc.. Here, a novel method based on the desorption atmospheric pressurechemical ionization mass spectrometry (DAPCI-MS) has been developed for fastdetection of sinapine in samples with complex matrix. In this study, the sinapine inmultiple crucifers, especially in radish taproot and on the surface of seeds were measuredusing DAPCI-MS without any sample preparation. The main objective of this work is tostudy the sinapine contents variation under different conditions, as well as therelationship between sinapine and seed vigor. The thesis is mainly referred to followingaspects:1A novel method, based on the desorption atmospheric pressure chemicalionization mass spectrometry (DAPCI-MS), has been developed here for fastdetection of sinapine in complex matrix using MeOH/H2O as desorptionreagent, without any sample pretreatment such as extraction, separation,purification and enrichment. The operating parameters for sinapine wereoptimized and characterized as well.2In order to find the source of sinapine rapidly and screen the sources of sinapine,the contents and distribution of sinapine in radish root have been quantitativedetermined directly, using DAPCI-MS without any sample pretreatment. And,sinapine contents have also been determined in six other cruciferous vegetablessuch as chinese cabbage, mustard, cabbage, and so on. The experiments showthat sinapine contents can reach pg/mm2in radish root. All of six other cruciferous vegetables have sinapine with different contents.3Study on sinapine contents under different conditions. Sinapine wereinvestigated by exploring on changes of sinapine in radish taproot duringsenescence, after nuclear radiation and ultraviolet radiation using theDAPCI-MS.4Without any sample pretreatment, the sinapine leakage on the surface ofCruciferous seeds was successfully detected by the DAPCI-MS. According tothe relationship between intensity of sinapine leakage and strength of seed vigor,a method for direct detection of cruciferous seed vigor by mass spectrometryhas been established here, which provides a new solution for fast andnondestructive methods for screening superior provenance.