Insights into the metabolite profiles of Rubus chingii Hu at different developmental stages of fruit.

The fruits of Rubus chingii Hu have high medicinal and nutritional values. However, the metabolite profiles of R. chingii, especially the alterations during different development stages of fruit, have not been comprehensively analyzed, hindering the effective utilization of the unique species. In this study, we comprehensively analyzed the metabolites of R. chingii fruit at four developmental stages using systematic untargeted and targeted liquid chromatography-mass spectrometry metabolomics analysis and identified 682 metabolites. Significant changes were observed in metabolite accumulation and composition in fruits during the different developmental stages. The contents of the index components, kaempferol-3-O-rutinoside and ellagic acid, were the highest in immature fruit. The analysis identified 64 differentially expressed flavonoids and 39 differentially expressed phenolic acids; the accumulation of most of these differentially expressed metabolites decreased with the developmental stages of fruit from immaturity to maturity. These results confirmed that the developmental stages of fruit are a critical factor in determining its secondary metabolite compositions. This study elucidated the metabolic profile of R. chingii fruit at different stages of development to understand the dynamic changes in metabolites.

Comprehensive metabolomics analysis of key taste components in different varieties of table grapes.

Grapes are one of the world's largest fruit crops, which are rich in nutrients and taste. Summer Black, Gui Fei, Kyoho Grape, Giant Rose, Shine Muscat, and Rosario Bianco are the six most popular table grapes in Wuxi city, Jiangsu province. Owing to the lack of comprehensive investigations of metabolites in table grapes, the metabolic causes of differences in their taste are unknown. In this study, metabolites of six table grapes were profiled using ultra-high-performance liquid chromatography-Q-Exactive Orbitrap tandem mass spectrometry combined with multivariate analysis. Orthogonal partial least squares discriminant analysis discriminated among the metabolites of these varieties. Metabolic pathway analysis revealed that carbohydrate and amino acid metabolisms were highly conserved among these varieties. Our results suggest that the taste differences in the six table grape varieties can be explained by variations in composition and abundance of carbohydrates, organic acids, amino acids, and polyphenols. This study provides comprehensive insights into the underlying metabolic causes of taste variation in table grapes.

[Difference of chemical constituents in Eucommiae Cortex from different habitats by LC-QTOF MS/MS].

In order to study the influence of ecological environment regarding the synthesis and accumulation of metabolites in Eucommiae Cortex, LC-QTOF MS/MS method combined with multivariate statistical analysis was used to analyze the differences of chemical constituents in Eucommiae Cortex from different habitats. Through the analysis of the multistage tandem mass spectrometry, the characteristic peaks were extracted with mass spectrometry data peak matching, peak alignment, and noise filtering. Principal component analysis (PCA) and partial least-squares discriminant analysis (PLS-DA) were used for data processing. The chemical constituents were identified or tentative presumed according to MS accurate mass and MS/MS spectrometry fragmentation information, combined with the software of database search, comparison with reference standards and literature. The results show the differences among samples of Eucommiae Cortex from different habitats are distinguishable. A total of 23 chemical constituents in Eucommiae Cortex were identified or tentative presumed. Among of them, 14 kinds of common differential chemical constituents (aucubin, geniposidic acid, neochlorogenic acid, syringin, olivil-4',4'-di-O-ß-D-glucopyranoside, chlorogenic acid, cryptochlorogenic acid, 1-hydroxypinoresinol- 4',4'-di-O-ß-D-glucopyranoside, caffeic acid, pinoresinol-di-O-ß-D-glucopyranoside, syringaresionl-di-O-ß-D-glucopyranoside, pinoresinol-4'-O-ß-D-glucopyranoside, eucommiol, isochlorogenic acid C and asiatic acid) presented different changing laws. This study provides basic information for revealing the influence law of ecological environment on the biosynthesis of metabolites in Eucommiae Cortex.

[iTRAQ-based quantitative proteomics of cultivated Pseudostellaria heterophylla and its wild type].

This work was designed to investigate proteins differentially expressed in cultivated Pseudostellaria heterophylla and its wild type using i TRAQ proteomics approach. The extracted proteins were digested using FASP method and identified by i TRAQ coupled with LC-MS/MS technology and then analyzed by Protein Pilot 5.0 search engine. Proteins differentially expressed were searched through comparison of relatively quantified proteins. The analysis was conducted using GO(gene ontology), KEGG and STRING. A total of 3 775 proteins were detected, among them, 3 676 proteins can be quantified, of which 127 proteins were up-regulated and 205 were down-regulated in cultivated Pseudostellaria heterophylla. We found 71 significantly differentially expressed proteins for further analysis. These proteins were classified into nine categories: heat shock proteins, transferases, oxidoreductases, lyases, isomerases, ligases, hydrolases, tubulin and translocases. The results indicated that the carbohydrate and cellular amino acids metabolism of cultivated Pseudostellaria heterophylla were weaker than its wild type and its ability of responding to stress was much stronger. GWD1, PHS1, GBE1, PGM, and BAM1 are the important proteins to regulate sucrose; met E and CYS are the key proteins that regulate amino acids in cultivated and wild Pseudostellaria heterophylla. This will provide the basic information for exploring the cause of secondary metabolites differences in different ecotype of Pseudostellaria heterophylla and the protein mechanism of its quality formation.

Chemical Differentiation of Pseudostellariae Radix from Different Cultivated Fields and Germplasms by UPLC-Triple TOF-MS/MS Coupled with Multivariate Statistical Analysis.

To explore rapidly the potential chemical markers for differentiating Pseudostellariae Radix from different cultivated fields :and germplasms, a method is proposed based on ultra-performance liquid chromatographytriple time-of-flight mass/mass spectrometry (UPLC-Triple TOF-MS/MS) coupled with multivariate statistical analysis. Peak matching, peak alignment, and noise filtering were used in analyzing mass spectrometric data. Accurate m/z value analysis of MS data based on software of database search and MS/MS fragment analysis were applied to identify constituents. The obtained. data were statistically analyzed with hierarchical cluster analysis (HCA), principal component analysis (PCA), and partial least squared-discriminant analysis (PLS-DA) to compare the differences among these samples. The PLS-DA loading plot obtained from all mass data showed that 21 compounds were identified as the potential chemical markers to characterize the samples. The results provide experimental data to reveal the influence of ecological environments and germplasms on metabolite biosynthesis in Pseudostellariae Radix.

[Simultaneous determination of thirteen components in Polygoni Multifori Caulis by UPLC-MS/MS].

A comprehensive analytical method based on UPLC-MS/MS was developed for the simultaneous determination of thirteen components including three stilbenes (stilbeneglucoside, polydatin, resveratrol), four anthraquinones (emodin, physcion, emodin-8-ß-D-glucopyranoside, aloe-emodin), five flavonoids (epicatechin, rutin, hyperoside, astragalin,quercetin) and one phenolic acid (gallic acid) in Polygoni Multifori Caulis.The separation was carried out on a Waters BEH C18 column（2.1 mm×100 mm,1.7 µm）with gradient elution of acetonitrile-water (0.1% acetic acid) at a flow rate of 0.25 mL•min⁻¹, and column temperature was 35 ℃. The target compounds were analyzed by multiple reaction monitoring (MRM) mode. TOPSIS analysis ware performed to evaluate the samples from different areas and commercial herbs according to the contents of thirteen components. The correlation coefficients of all the calibration curves were higher than 0.991 5. The average recoveries ranged from 95.24% to 102.3%, and the relative standard deviations were less than 5%. The result of TOPSIS analysis showed that the comprehensive quality of Polygoni Multifori Caulis sample from Guangzhou was better. The developed method with good repeatability and accuracy was suitable for the simultaneous determination of multiple functional substances, which provided a new basis for the comprehensive assessment and overall control of the quality of Polygoni Multifori Caulis.