Project description:Paeonia lactiflflora Pall. has a long edible and medicinal history because of the very high content of biologically active compounds. However, little information is available about the metabolic basis of pharmacological values of P. lactiflora flowers. In this study, we investigated metabolites in the different parts of P. lactiflora flowers, including petal, stamen petaloid tissue and stamen, by widely targeted metabolomics approach. A total of 1102 metabolites were identified, among which 313 and 410 metabolites showed differential accumulation in comparison groups of petal vs. stamen petaloid tissue and stamen vs. stamen petaloid tissue. Differential accumulated metabolites analysis and KEGG pathway analysis showed that the flavonoids were the most critical differential metabolites. Furthermore, difference accumulation of flavonoids, phenolic acids, tannins and alkaloids might lead to the differences in antioxidant activities and tyrosinase inhibition effects. Indeed, stamen petaloid tissue displayed better antioxidant and anti-melanin production activities than petal and stamen through experimental verification. These results not only expand our understanding of metabolites in P. lactiflora flowers, but also reveal that the stamen petaloid tissues of P. lactiflora hold the great potential as promising ingredients for pharmaceuticals, functional foods and skincare products.
Project description:Sweet corn (Zea mays convar. saccharata var. rugosa) is a major economic vegetable crop. Different sweet corn cultivars vary largely in flavor, texture, and nutrition. The present study performed widely targeted metabolomics analysis based on the HPLC-MS/MS technology to analyze the metabolic profiles in three sweet corn cultivars widely grown in China. A total of 568 metabolites in the three sweet corn cultivars were detected, of which 262 differential metabolites significantly changed among cultivars. Carbohydrates, organic acids, and amino acids were the majority detected primary metabolites. Organic acids were mainly concentrated on shikimate, benzoic acids, and quinic acid with aromatic groups. And the essential amino acids for the human body, methionine and threonine, were highly accumulated in the high-quality cultivar. In addition, phenylpropanoids and alkaloids were the most enriched secondary metabolites while terpenes were low-detected in sweet corn kernels. We found that the flavonoids exist in both free form and glycosylated form in sweet corn kernels. PCA and HCA revealed clear separations among the three sweet corn cultivars, suggesting distinctive metabolome profiles among three cultivars. The differential metabolites were mapped into flavonoid biosynthesis, phenylpropanoid biosynthesis, biosynthesis of amino acids, and other pathways according to the KEGG classification. Furthermore, we identified skimmin, N',N″-diferuloylspermidine, and 3-hydroxyanthranilic acid as the key quality-related metabolites related to grain quality traits in sweet corn. The results suggested variations of metabolic composition among the three cultivars, providing the reference quality-related metabolites for sweet corn breeding.
Project description:Herbaceous peony (Paeonia lactiflora Pall.) is an important ornamental and medicinal plant. DNA barcodes can reveal species identity via the nucleotide diversity of short DNA segments. In this study, two main candidate DNA barcodes (ITS2 and psbA-trnH) were tested to identify twenty-one cutting cultivars of P. lactiflora and their wild species. The efficacy of the candidate DNA barcodes was assessed by PCR amplification, sequence quality, sequence diversity, rate of correct identification, and phylogenetic analysis. ITS2 was easy to be amplified and sequenced among the samples. The identification by Blastn and phylogenetic analysis was 95.4% and 63.6%, respectively. For psbA-trnH, the presence of poly A-T led to sequencing failure which limited its use as DNA barcode candidate. Moreover, the authentic efficiency of psbA-trnH was lower than ITS2. The results showed that ITS2 is suitable as a candidate DNA barcode for the intraspecific identification of P. lactiflora cultivars.
Project description:Baijiu is prepared via solid fermentation and distillation, and volatile metabolites influence its flavor considerably. However, the volatile metabolites' transformational relationship during the fermentation process remains unclear. In this study, ultra-performance liquid chromatography-tandem mass spectrometry and gas chromatography-tandem mass spectrometry were used to analyze a widely targeted metabolome during the xiaoqu baijiu fermentation process. In total, 668 volatile metabolites comprising 16 subclasses were identified. Significant variations in metabolites were observed during the fermentation process, especially in the distillation stage, and the conversion intensity of volatile metabolites was consistent with the following order of stages: distillation > soaking > saccharification > fermentation > stewing. A total of 570 differential volatile metabolites were identified in the distillation stage, especially esters, terpenoids, and hydrocarbons. These results provide a theoretical basis that could guide the xiaoqu baijiu fermentation process based on desired quality and components.
Project description:As a semifermented tea, oolong is exceedingly popular worldwide for its elegant, flowery aroma and mellow, rich taste. However, recent marketing trends for old oolong teas and their chemical quality largely remain unexplored. In this study, we applied widely targeted metabolomics using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) combined with multivariate analysis to investigate the chemical change of oolong teas in the aging process. With the increasing of store time, most nongalloylated catechins; tannins, including TFs and proanthocyanidins; flavonols and glycosylated flavonols; amino acids and their derivatives; nucleotides and their derivatives; and lots of alkaloids and phospholipids declined, while most fatty acids and organic acids increased, and galloylated catechins, GA, and caffeine were almost stable. The result also suggested that approximately seven years (but not an infinite extension) was a special period for oolong tea storage, which brings about excellent taste.
Project description:The flavor differences in Oolong tea from different producing areas are caused by its complex differential compounds. In this study, representative samples of Oolong tea from four countries were collected, and their differential nonvolatile compounds were analyzed by a combination of widely targeted metabolomics, chemometrics, and quantitative taste evaluation. A total of 801 nonvolatile compounds were detected, which could be divided into 16 categories. We found that the difference in these compounds' content among Oolong teas from three producing areas in China was the largest. There were 370 differential compounds related to the producing areas of Oolong tea, which were mainly distributed in 67 Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathways. In total, 81 differential nonvolatile compounds made important contributions to the taste differences in Oolong tea from different producing areas, among which the number of flavonoids was the largest. Finally, the characteristic compounds of Oolong tea in six producing areas were screened. This study comprehensively identifies the nonvolatile compounds of Oolong tea in different producing areas for the first time, which provides a basis for the analysis of flavor characteristics, quality directional control, and the identification and protection of geographical landmark agricultural products of Oolong tea from different producing areas.
Project description:Fermentation is an effective means of enhancing the nutritional value of natural medicines, however, it is unclear how the metabolites changed during the fermentation of Paeonia lactiflora root (PLR). This study intends to elucidate how the active constituents and antioxidant activity of PLR change during fermentation. The study examined the levels of total glucosides of paeony (TGP), total flavonoids content (TFC), total phenols content (TPC), and antioxidant capability by high performance liquid chromatography (HPLC) and spectrophotometry. The chemical compositions before and after PLR fermentation were compared utilizing ultra-high performance liquid chromatography-mass spectrometry (UHPLC - MS). The findings from this study indicate that TGP, TFC and TPC peaked at Day 2 of fermentation, and the antioxidant capacity increased after fermentation. Of the 109 detected compounds, 18 were discrepant compounds. In summary, fermentation is an essential strategy for enhancing the functional activity of PLR. The current study could establish a scientific basis for future research on the fermentation of PLR, and provides new insights into the influence of fermentation on chemical composition as well as the antioxidant activity of drugs.
Project description:The pomegranate fruit is valued for its nutritional and medicinal properties, and the composition and content of primary and secondary metabolites are the main factors impacting its nutritional and medicinal properties. However, a deep understanding of metabolites in different parts of fruit is still lacking. Here, the peel, aril, and seed of mature pomegranate fruits were analyzed separately to compare metabolic component differences using UPLC/MS-MS. A total of 858 metabolites belonging to 11 classes were identified, of which flavonoids, such as delphinidin-3-O-glucoside and cyanidin-3-O-glucoside; tannins, such as ellagic acid and punicalin; and terpenoids, such as corosolic acid and madasiatic acid, were upregulated in the peel. Lipids, such as punicic acid, methyl linolenate, and linoleic acid; alkaloids, such as indole and choline; nucleotides and derivatives mainly including 2-deoxyribose-1-phosphate and 9-(arabinosyl)-hypoxanthine, were upregulated in seeds. Phenolic acids, such as 1-O-galloyl-4,6-(S)-HHDP-β-D-glucose and 1,7-di-O-galloyl-D-sedoheptulose, and flavonoids, such as cyanidin-3-O-glucoside, cyanidin-3-O-(2″-O-xylosyl) galactoside, and delphinidin-3-O-glucoside, were upregulated in aril. The flavone and flavonol biosynthesis (ko00944) pathways were significantly enriched between the peel and seed, as were the anthocyanin biosynthesis (ko00944) pathways between the aril and seed and the flavonoid biosynthesis (ko00941) pathways between the peel and aril. Additionally, functional antioxidants, such as 10,16-dihydroxypalmitic acid, 3-O-methylellagic acid, and 3,3'-O-dimethylellagic acid, were first identified in pomegranate fruits. Our results revealed the composition and abundance of primary and secondary metabolites in pomegranate fruit, which can lay the foundation for further elucidation of its nutritional and medicinal properties.
Project description:Citrus cultivars are widely spread worldwide, and some of them only differ by specific mutations along the genome. It is difficult to distinguish them by traditional morphological identification. To accurately identify such similar cultivars, the subtle differences between them must be detected. In this study, UPLC-ESI-MS/MS-based widely targeted metabolomics analysis was conducted to study the chemical differences between two closely related citrus cultivars, Citrus reticulata 'DHP' and C. reticulata 'BZH'. Totally 352 metabolites including 11 terpenoids, 35 alkaloids, 80 phenolic acids, 25 coumarins, 7 lignans, 184 flavonoids and 10 other compounds were detected and identified; Among them, 15 metabolites are unique to DHP and 16 metabolites are unique to BZH. Hierarchical cluster analysis (HCA), principal component analysis (PCA), and orthogonal signal correction and partial least squares-discriminant analysis (OPLS-DA) can be used to clearly discriminate between DHP and BZH. 93 metabolites including 36 down-regulated and 57 up-regulated are significantly different in DHP and BZH. They are mainly involved in the biosynthesis of flavonoids, flavones, flavonols, and isoflavonoids. In addition, the relative content levels of flavonoids, alkaloids, and terpenoids are much higher in the peel of DHP than that of BZH, the presence of which may correlate with the quality difference of the peels. The results reported herein indicate that metabolite analysis based on UPLC-ESI-MS/MS is an effective means of identifying cultivars with different genotypes, especially those that cannot be distinguished based on traditional identification methods.