RESUMO
Due to the diversity and complexity, the change of chemical components in medicinal plant according to the time, cultivated varieties or ecological condition is difficult to recognize using traditional phytochemistry method. In order to analyze the pharmacodynamics material basis in Uighur medicinal plant Artemisia rupestris L. in an effective and comprehensive way, a plant metabolomics approach was established based on liquid chromatography-tandem mass spectrometry (LC-MS/MS). This study firstly focused on the effect of extraction solvents,redissolve solvents and ultrasonic time on the untargeted metabolomics, then the optimal preparation condition was selected according to metabolites coverage. After methodology validation, the approach was applied to acquire metabolic information in root, stem, branchlet, leaf and flower of Artemisia rupestris L. The results showed that the metabolome in flower was obviously different with the other organs. Coupling with multivariate statistical analysis, a batch of differential metabolites were picked out, in which 61 flavonoids, 97 rupestonic acid derivatives, 7 chlorogenic acids and 15 other compounds were primarily recognized according to the characteristic fragmentation rules of specific structure type and database retrieval. Additionally,the distribution characteristics of the above 180 differential metabolites was illustrated by cluster heat map. In conclusion,this study provided important information about the rational utilization of effective parts from Artemisia rupestris L.,and offered a novel strategy for quality control,variety improvement and reasonable development of medicinal plants.
RESUMO
As a promising new molecular imaging technique,mass spectrometry imaging(MSI) has attracted more and more attention in the field of biomedicine. A method of air flow assisted ionization-ultra high resolution mass spectrometry-based mass spectrometric imaging (AFAI-MSI) was developed to profile endogenous metabolites in rat kidney tissue in this study. Rat kidneys were collected and cut into frozen tissue sections,and then were analyzed on an AFAI-MSI system in positive ion mode using acetonitrile-isopmpyl alcohol-water (4:4:2,V/V,5 μL/min) as spray solvent,N2as spray gas(0.6 MPa) and air as assisting gas (45 L/min). The mass range and resolution were set to be 70-1000 Da and 70000, respectively. As a result,a total of 38 metabolites, including organic amines, sugars, vitamins, peptides, neurotransmitters, organic acids,phospholipids,sphingolipids,glyceride,and cholesterol esters, were identified and imaged to characterize their tissue-specific distribution in kidney tissues, and some metabolites, such as choline, acetylcoline,betaine,phoshocholine,and glycerophosphocholine were found to have distinct distribution along the cortex-medulla axis,which may be involved in the formation of osmotic pressure gradient in the kidney. The proposed ultra high resolution mass spectrometry based AFAI-MSI method could work without sample pretreatment, showed high sensitivity and wide metabolite coverage, and was expected to provide a new analytical approach for the research of in situ characterization and metabolic regulation mechanism of endogenous metabolites in kidney.