Application of UHPLC-Q-TOF MS based untargeted metabolomics reveals variation and correlation amongst different tissues of Eucommia ulmoides Oliver

Identification of novel natural anti-browning agents based on phenotypic and metabolites differences in potato cultivars

This study aimed to elucidate the changes of browning-related metabolite in fresh-cut potato and to identify anti-browning agents. Metabolomics and weighted correlation network analysis (WGCNA) were used to identify metabolites and correlate them with potato browning traits. A total of 79 browning trait-positive-related metabolites and 19 browning trait-negative-related metabolites were obtained from four key modules via WGCNA. The accumulation of metabolites with rich reducing groups and acidic groups were found to enhance anti-browning activity in potatoes. Among these metabolites, only L-pyroglutamic acid (L-PA) and ascorbic acid had variable importance for the projection (VIP) values greater than 1.5. In addition, it was found that L-PA inhibited polyphenol oxidase (PPO) activity by lowering pH and interacting with amino acid residues of PPO. L-PA also inhibited the growth of microorganisms in fresh-cut potato. Our results show that L-AP is an effective novel anti-browning agent with antibacterial activity.

Comparative study on metabolite variations of two rose teas by plant metabolomics and revealing their skin-whitening candidates by spectrum-effect relationship analysis

INTRODUCTION

Rosa rugosa var. plena Rehd (CBR) and Rosa chinensis cv. "JinBian" (JBR) are two common species used in rose tea among different original species. CBR, the officially documented original plant of the rose species for food and medicinal purposes, is more costly than JBR. With increasing demand for different rose teas, it is meaningful to compare the chemical constituents for their quality control and reveal their skin-whitening components that will provide in-depth insights for the expansion of the rose tea industry.

OBJECTIVE

This study aims to reveal the chemical variances between CBR and JBR and determine their skin-whitening components.

METHODOLOGY

A strategy obtained by combining MS-based plant-metabolomics with spectrum-effect relationship analysis has been proposed for unveiling chemical differences between CBR and JBR and further exploring their potential skin-whitening components.

RESULTS

A total of 2030 metabolites were found that revealed considerable differences between CBR and JBR. The results of bioactivity assay demonstrated that JBR exhibited stronger tyrosinase inhibition activity than CBR. Six potential skin-whitening compounds (di-O-galloyl-HHDP-glucoside, tri-O-galloyl-HHDP-glucoside, spiraeoside, quinic acid, rugosin A, and 1,2,3,6-tetra-O-galloyl-glucose) were discovered as potential tyrosinase inhibitors, via spectrum-effect relationship analysis. This is the first time that di-O-galloyl-HHDP-glucoside, tri-O-galloyl-HHDP-glucoside, rugosin A, and 1,2,3,6-tetra-O-galloyl-glucose have been reported with tyrosinase inhibitory activity. Additionally, molecular docking analysis was used to reveal the inhibition mechanism of these compounds toward tyrosinase.

CONCLUSION

The finding of this study will be of great importance for the quality control of the two types of rose teas, and the revealed active ingredients will provide in-depth insights for the expansion of the rose tea industry.

Non-targeted metabolomics and explainable artificial intelligence: Effects of processing and color on coniferyl aldehyde levels in Eucommiae cortex

Eucommia ulmoides, a plant native to China, is valued for its medicinal properties and has applications in food, health products, and traditional Chinese medicine. Processed Eucommiae Cortex (EC) has historically been a highly valued medicine. Ancient doctors had ample experience processing EC, especially with ginger juice, as documented in traditional Chinese medical texts. The combination of EC and ginger juice helps release and transform the active ingredients, strengthening the medicine's effectiveness and improving its taste and shelf life. However, the lack of quality control standards for Ginger-Eucommiae Cortex (G-EC), processed from EC and ginger, presents challenges for its industrial and clinical use. This study optimized G-EC processing using the CRITIC and Box-Behnken methods. Metabolomics showed 517 chemical changes between raw and processed G-EC, particularly an increase in coniferyl aldehyde (CFA). Explainable artificial intelligence techniques revealed the feasibility of using color to CFA content, providing insights into quality indicators.

Insights into the effects of anilofos on direct-seeded rice production system through untargeted metabolomics

Weed infestation is the major biological threat in direct-seeded rice production and can cause significant yield losses. The effective use of herbicides is particularly important in direct-seeded rice production. Anilofos, a pre-emergence herbicide, has been shown to be effective against the weed barnyardgrass. However, its impacts on crop yield and the direct-seeded rice production ecosystem remain underexplored. In this study, we conducted field trials and used untargeted metabolomics to investigate systemic effects of two different treatments (40 g/acre and 60 g/acre) on rice shoot and root as well as the rhizosphere soil during the critical tillering stage. Here, a total of 400 metabolites were determined in the crop and soil, with differential metabolites primarily comprising lipids and lipid-like molecules as well as phenylpropanoids and polyketides. Spearman correlation network analysis and a Zi-Pi plot revealed 7 key differential metabolites with significant topological roles, including succinic acid semialdehyde and riboflavin. KEGG pathway analysis showed that anilofos downregulated the amino acid metabolism while mainly promoted carbohydrate metabolism and secondary metabolites biosynthesis of the crop, which made minimal disruption on soil metabolism. Notably, we found 40 g/acre anilofos application could significantly improve the rice yield, potentially linked to the improved activity of flavonoid biosynthesis and starch and sucrose metabolism. This research provides a comprehensive evaluation of anilofos effects in the direct-seeded rice production system, offering new insights into optimizing herbicide use to improve agricultural sustainability and productivity.

Insights into Tissue-Specific Specialized Metabolism in Wampee (Clausena lansium (Lour.) Skeels) Varieties

Wampee (Clausena lansium (Lour.) Skeels) has natural bioactive components with diverse health benefits, but its detailed metabolism and tissue distribution are not fully understood. Here, widely targeted metabolomics analysis methods were employed to analyze the wampee fruit (peel, pulp, and seed) of 17 different varieties. A total of 1286 metabolites were annotated, including lipids, flavonoids, polyphenols, carbazole alkaloids, coumarins, and organic acids, among others. The quantitative analysis and matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) analysis indicated remarkable variations in metabolite categories and content in the peel, pulp, and seed of wampee fruit. Additionally, the difference analysis found that the metabolic components of peel contributed dominantly to the differences among varieties, and 7 potential biomarkers were identified. In this study, a comprehensive metabolome landscape of wampee fruit was established, which provided important information for the isolation and identification of functional components, food industry application, and nutritional improvement breeding.

Analysis of the Volatile Components in Different Parts of Three Species of the Genus Amomum via Combined HS-SPME-GC-TOF-MS and Multivariate Statistical Analysis

The study used headspace solid-phase microextraction coupled with gas chromatography-time-of-flight mass spectrometry (HS-SPME-GC-TOF-MS) to analyze volatile compounds in leaves and fruits of Amomum tsaoko, Amomum paratsaoko, and Amomum koenigii. The composition and aroma of distinct metabolites were analyzed using multivariate statistical methods. A total of 564 volatile compounds were identified from three species of the genus Amomum, which were further divided into nine categories: terpenoids, carboxylic acids, alcohols, hydrocarbons, aldehydes, ketones, phenols, ethers, and other compounds. Terpenoids and alcohols were the most abundant. The content and types of compounds vary in A. tsaoko, A. paratsaoko, and A. koenigii, so mixing or substituting them is not advisable. We selected 45 metabolites based on the criteria of the variable importance in projection values (VIP > 1.5) and one-way ANOVA (p < 0.05). The top 19 metabolites with the most significant VIP values were chosen. Interestingly, (Z)-2-decenal was only found in Amomum koenigii, while nitroethane and nonanal were only present in cultivated A. tsaoko. Additionally, linalool, cineole, and (D)-limonene were the main components affecting the aroma of three species of the genus Amomum. The volatile components identified in this study provide a theoretical basis for analyzing the unique flavor of A. tsaoko, A. paratsaoko, and A. koenigii.

Metabolomic differences between non-hydrothermal treated water-soluble (WSPs) and hydrothermally treated water-insoluble (WIPs) Maitake polysaccharides fermented by Lactobacillus acidophilus and L. plantarum

Bacterial Metabolite through a fermentation process is a growing trend and a promising alternative for use as functional components. Non-hydrothermal water-soluble (WSPs) and hydrothermally treated water-insoluble (WIPs) Maitake polysaccharides were fermented with Lactobacillus acidophilus (LA) and Lactobacillus plantarum (LP). Chemical composition analysis indicated that Maitake polysaccharides contained 58.22 ± 1.35 % total sugar and 31.46 % β-glucan, essential for metabolites production. 6-glucanase was used to degrade the WIPs, and hydrothermally treated WIP fibers exhibited smooth microstructure. Hence, the LA and LP bacteria investigated the potential fermented metabolic activities and differences between WSPs(Sp1)and WIP(Sp3) Maitake polysaccharides using LC-MS, and 887 metabolites were identified. Using Venn, Partial least squares discriminant analysis (PLS-DA), VIP Metabolites, and other multivariate statistical analysis methods, metabolites were expressed differently in all samples. Due to hydrothermal processing, WIP induced the highest growth of LA and LP, with an abundance of isocitrate metabolites. Furthermore, 50 metabolite correlations were identified, leading to the classification of 6 distinct metabolic groups. Thus, the study offers the initial comprehensive analysis of metabolites in Lactobacillus-fermented Maitake polysaccharides, aiding in understanding its metabolic interactions and facilitating progress in food engineering research.

Chemical characterization, multivariate analysis and comparison of biological activities of different parts of Fraxinus mandshurica

Fraxinus mandshurica (Oleaceae) is used as a traditional medicinal plant for the treatment of red eyes, menstrual disorders, excessive leucorrhea, chronic bronchitis and psoriasis. To perform chemical characterization of the secondary metabolites of F. mandshurica roots, bark, stems and leaves, 32 samples were collected from eight provinces in this study. A total of 64 chemical components were detected from four different parts of F. mandshurica by ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry. Meanwhile, a total of nine secoiridoids were obtained by natural product chemical extraction, isolation and identification methods. Quantitative analysis by high-performance liquid chromatography-diode array detection-mass spectrometry showed the highest total content of secoiridoids in the bark, which is also consistent with the traditional medicinal parts. The results of methodological validation showed that the correlation coefficient (R2) values were all >0.9993, indicating a good linear range of the standard curve, while the relative standard deviations of precision, reproducibility and stability were <3%, and the spiked recoveries ranged from 98.22 to 102.27%, indicating that the experimental method was reliable and stable. In addition, fingerprinting and a heatmap were established to demonstrate the content trends of F. mandshurica more visually from different origins. Multivariate analysis, including principal component analysis and partial least squares discriminant analysis, was performed to determine the chemical characteristics of different parts of F. mandshurica, and six characteristic secoiridoids that could be used to distinguish different origins were screened. Finally, the inhibition of tyrosinase, α-glucosidase, acetylcholinesterase and pancreatic lipase activities by the nine characteristic compounds and extracts from different parts were investigated, and the results showed that they all exhibited different degrees of enzyme activity inhibition and thus have potential applications in whitening and blemish removal, hypoglycemia, anti-Alzheimer's disease and anti-obesity as a new source of natural enzyme activity inhibitors. This study establishes an identification and evaluation method applicable to phytochemistry of different origins, which is a guideline for quality control, origin evaluation and clinical application of traditional medicinal plants. This is also an unprecedented study on the identification of the chemical composition of different parts of F. mandshurica, characteristic compounds and the inhibition of enzyme activity of extracts from different parts.

Metabolomics reveals factors affecting the radical reaction of sulfides during thermal processing for meaty aroma

The effects of cysteine (Cys), glutathione (GSH) and cystine (GCys) on sulfides and meaty aroma were studied based on concentration monitoring and metabolomics. In multi-component models, Cys and GSH demonstrated a greater capacity to decrease dimethyl trisulfide (DMTS) levels and increase the proportion of 2-methyl-3-furanthiol (MFT), compared with GCys. Moreover, no discernible difference between Cys and GSH in dynamic profiles of volatiles to further analyze the synergistic effect of both. Results of single factor experiment and optimization revealed that the optimal thermal processing was a second-order thermal procedure. Aroma profiles revealed that the addition of Cys and GSH mixture increased the meaty intensity during the optimal thermal processing. Metabolomics based on Encyclopedia of Genes and Genomes pathway annotation confirmed that Cys and GSH significantly affected the degradation of methionine and thiamine in amino acid and protein metabolic pathways, resulting in various amounts of DMTS and MFT. Research on effect and potentially metabolic mechanisms revealed that the combination of Cys and GSH at ratio of 3:7 had higher and more effective control capacity for free radical reaction of sulfides than either one alone during second-order thermal processing, which would lay theoretical foundation for the development of high-quality thermal process products.

Assessing the impact of Chlorantraniliprole (CAP) pesticide stress on oilseed rape (Brassia campestris L.): Residue dynamics, enzyme activities, and metabolite profiling

This study investigates the effects of chlorantraniliprole (CAP) pesticide stress on oilseed rape through comprehensive pot experiments. Assessing CAP residue variations in soil and oilseed rape (Brassia campestris L.), enzyme activities (POD, CPR, GST), and differential metabolites, we unveil significant findings. The average CAP residue levels were 18.38-13.70 mg/kg in unplanted soil, 9.94-6.30 mg/kg in planted soil, and 0-4.18 mg/kg in oilseed rape samples, respectively. Soil microbial influences and systemic pesticide translocation into oilseed rape contribute to CAP residue variations. Under the influence of CAP stress, oilseed rape displays escalated enzyme activities (POD, CPR, GST) and manifests 57 differential metabolites. Among these, 32 demonstrate considerable downregulation, mainly impacting amino acids and phenolic compounds, while 25 exhibit noteworthy overexpression, primarily affecting flavonoid compounds. This impact extends to 24 metabolic pathways, notably influencing amide biosynthesis, as well as arginine and proline metabolism. These findings underscore the discernible effects of CAP pesticide stress on oilseed rape.

Comparative metabolic profiling of mycelia, fermentation broth, spore powder and fruiting bodies of Ophiocordyceps gracilis by LC-MS/MS

INTRODUCTION

Ophiocordyceps gracilis, a type of edible and medicinal fungus, exhibits multiple health-promoting effects. Due to the scarcity of natural O. gracilis, artificial cultures have been developed as its substitutes. However, lacking comprehension of the metabolite composition of cultures limits its utilisation.

OBJECTIVE

This research aimed to evaluate the nutritional and medicinal value of four cultures of O. gracilis by analysing their metabolite composition. In addition, metabolic pathways in mycelia and fruiting bodies were analysed to explore fruiting body formation mechanism at metabolic level.

METHOD

The mycelia, fermentation broth, spore powder and fruiting bodies of O. gracilis were cultivated in this study. Their metabolite composition was compared using an untargeted metabolomics approach based on liquid chromatography-tandem mass spectrometry (LC-MS/MS).

RESULTS

Principal component analysis (PCA) and orthogonal projections to latent structures discriminant analysis (OPLS-DA) showed that the four cultures have noticeable differences in metabolite composition. A total of 612 metabolites were identified, among which 159 metabolites showed significant differences, and these differential metabolites were classified into 13 categories. The metabolites in the fruiting bodies were the most abundant compared with other cultures. However, each culture had its own advantages and significantly accumulates some active metabolites respectively. Pearson's correlation analysed the mutual relationship among metabolites. In addition, seven metabolic pathways were closely related to fruiting body formation, such as "Biosynthesis of plant secondary metabolites", "amino acids metabolism", "tricarboxylic acid (TCA) cycle".

CONCLUSION

This study offered a reference to mycelia, fermentation broth, spore powder and fruiting bodies of O. gracilis as health-promoting functional foods and medicine.

Metabolomics Analysis of Different Tissues of Lonicera japonica Thunb. Based on Liquid Chromatography with Mass Spectrometry

Lonicera japonica Thunb. (LJT) has been widely used as medicines or food additives in Asian countries for thousands of years. The flower buds are often medicinally used, and the other tissues are ignored. However, flowers, leaves and stems have also been reported to have antimicrobial, anti-inflammatory and antioxidant effects. In the current study, un-targeted metabolomics analysis was performed to investigate the metabolic difference among different tissues (flowers, flower buds, stems and leaves) of LJT based on liquid chromatography with mass spectrometry. A total of 171 metabolites were identified, including 28 flavonoids, 35 phenolic acids, 43 iridoids, 9 amino acids, 6 nucleotides, 16 fatty acids, 22 lipids and 12 others. Four new secondary metabolites were discovered. Some flavonoids and iridoids were not detected in leaves and stems. Principal component analysis showed significant differences among four different tissues. Some 27, 81, 113 differential metabolites were found between flowers/flower buds, leaves/flower buds, stems/flower buds, respectively. Primary metabolites showed a higher content in the flowers and flower buds. For the flavonoids, flavones were mainly accumulated in the leaves, flavonols were mainly accumulated in the flower buds, and acylated flavonol glucosides were mainly accumulated in the flowers. Most phenolic acids showed a higher content in the flowers or flower buds, while phenolic acid-glucosides showed significantly higher content in the flower buds. The most abundant iridoids in the LJT also showed a higher content in the flowers and flower buds. These results can provide new insights into the understanding of the metabolites changes in different tissues, and lay a theoretical foundation for the comprehensive utilization of LJT.

Analysis of chemotypes and their markers in leaves of core collections of Eucommia ulmoides using metabolomics

The leaves of Eucommia ulmoides contain various active compunds and nutritional components, and have successively been included as raw materials in the Chinese Pharmacopoeia, the Health Food Raw Material Catalogue, and the Feed Raw Material Catalogue. Core collections of E. ulmoides had been constructed from the conserved germplasm resources basing on molecular markers and morphological traits, however, the metabolite diversity and variation in this core population were little understood. Metabolite profiles of E. ulmoides leaves of 193 core collections were comprehensively characterized by GC-MS and LC-MS/MS based non-targeted metabolomics in present study. Totally 1,100 metabolites were identified and that belonged to 18 categories, and contained 120 active ingredients for traditional Chinese medicine (TCM) and 85 disease-resistant metabolites. Four leaf chemotypes of the core collections were established by integrated uses of unsupervised self-organizing map (SOM), supervised orthogonal partial least squares discriminant analysis (OPLS-DA) and random forest (RF) statistical methods, 30, 23, 43, and 23 chemomarkers were screened corresponding to the four chemotypes, respectively. The morphological markers for the chemotypes were obtained by weighted gene co-expression network analysis (WGCNA) between the chenomarkers and the morphological traits, with leaf length (LL), chlorophyll reference value (CRV), leaf dentate height (LDH), and leaf thickness (LT) corresponding to chemotypes I, II, III, and IV, respectively. Contents of quercetin-3-O-pentosidine, isoquercitrin were closely correlated to LL, leaf area (LA), and leaf perimeter (LP), suggesting the quercetin derivatives might influence the growth and development of E. ulmoides leaf shape.

Analysis of flavonoid-related metabolites in different tissues and fruit developmental stages of blackberry based on metabolome analysis

Blackberry is an economically important shrub species of Rubus in the Rosaceae family. It is rich in phenolic compounds, which have many health effects and pharmaceutical value. The utilization of metabolites from various blackberry tissues is still in the primary stage of development, so investigating the metabolites in various tissues is of practical significance. In this study, nontargeted LC - MS metabolomics was used to identify and measure metabolites in the roots, stems, leaves and fruits (green, red, and black fruits) of blackberry "Chester". We found that 1,427 and 874 metabolites were annotated in the positive and negative ion modes (POS; NEG), respectively. Differentially abundant metabolites (DAMs) between the leaf and root groups were the most abundant (POS: 249; NEG: 141), and the DAMs between the green and red fruit groups were the least abundant (POS: 21; NEG: 14). Moreover, the DAMs in different fruit development stages were far less than those in different tissues. There were significant differences in flavonoid biosynthesis-related pathways among the comparison groups. Trend analysis showed that the profile 10 had the largest number of metabolites. This study provides a scientific basis for the classification and efficient utilization of resources in various tissues of blackberry plants and the directional development of blackberry products.