| Plant secondary metabolites are a large group of small moleculecompounds produced in plants. They are closely related to biologicalphenomena. Because of the complexity of the plants, the plantsecondary metabolites and their activity are not clear enough.Therefore, it is necessary to study plant secondary metabolitessystematically. Plant metabolomics is a non biased and essentiallycomprehensive high throughput analysis of complex metabolite mixtureswhich are typical part of plant extracts. Metabolic fingerprinting is animportant part of plant metabolomics research.In this research, a method of metabolic fingerprints was establishedfor the model plant Arabidopsis thaliana. An ultra performance liquidchromatography coupled with electrospray ionization quadrupole/time offlight mass spectrometry (UPLC ESI Q/TOF MS) was employed. Baseon the MS/MS spectrum and data from the literatures, twenty compounds were identified. The metabolite fingerprints of the four different organsof A. thaliana (rosette leaves, stems, flowers and stem leaves), differentgrowth times (leaf production, peduncle growth, flowering, siliqueripening), with and without salt stress were compared, respectively. Theprincipal components analysis (PCA) and partial leastsquares discriminant analysis (PLS DA) were applied for data treatment.The jasmonic acid (JA) content of each groups were determinated byHPLC QQQ MS. The fragmentation pathway of four types of planthormones (auxins, cytokinins (CKs), gibberellins (GAs), and abscisicacid (ABA)) was studied by employing ESI Q/TOF MS. Through thehigh resolution of the TOF MS, the exact mass charge ratio for all themolecular ions and fragment ions were determined to deduce theelemental compositions. The rapid method for the simultaneousdeterminations of seven phytohormones (indole3acetic acid,indole3propionic acid, indole3butyric acid,2, 4Dichlorophenoxyacetic acid, ABA,6benzylaminopurine, gibberellinA) was developed by HPLC QQQ. UPLC Q/TOF coupled with aluciferase reporter assay system for nuclear factor κB (NF κB) inhibitoractivity was established for screening potential NF κB inhibitors in theFlos Lonicerae Japonicae (FLJ) extract.The results showed that several compounds (kaempferitrin, robinin,kaempferol3O glucoside7O rhamnoside, kaempferol rhamnoside,and hirsutin) were significant marker in the different organs of A.thaliana. Five biomarkers (sinapoyl malate, arabidopside A, arabidopsideE, arabidopside G, and arabidopside D) of different growth time of A.thaliana were also found.12oxophytodienoic acid (OPDA),arabidopside A, sinapoyl malate, linolenic acid, and abscisic acid wererevealed as markers of salt stress. The determination results of JA contentindicated that salt stress increased the JA levels in the leaves of the WTplant. Linolenic acid and OPDA are the biosynthetic precursors of JA by the octadecanoid pathway. The MS/MS spectra library on ESI Q/TOF ofthe plant hormones was built. The same characteristic productive ions orcharacteristic neutral loss were observed and identified for a certain classof plant hormones. By using this system, six potentially activeingredients including secoxyloganin, loganic acid, swertiamarin,sweroside, aldosecologanin, and chlorogenic acid were identified basedon the mass spectrometric fragmentation. After the in vitro biologicalevaluation and content determination, chlorogenic acid and swertiamarinwere determined to be the main pharmacological compounds.In this research, the distribution of different organs and growth timeswere investigated. It provided the information for the study of thesynthesis and transport of secondary metabolites. The study of plantresponse to salt stress and salt tolerance mechanism is beneficial toimprove its salt tolerance, and the production of the crop plant andmedicinal plants. The identification strategy utilized in this study clearly demonstrates that the anti inflammatory effect of FLJ results in itseffects on multiple targets. |
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