Assessment of peeling of Astragalus roots using 1H NMR- and UPLC-MS-based metabolite profiling

Rapid preparation and proton NMR fingerprinting of polysaccharides from Radix Astragali

The purity, content, and structure of the polysaccharides prepared from a specific medicinal plant are the fundamental basis to interpret the observed biological activities. An ultrafiltration-based method has been developed for rapid preparation of total and fractional polysaccharides from Radix Astragali in high yield and purity. This method involves extraction of plant material by hot water, treatment with Sevag reagent, and ultrafiltration using molecular weight cutoff concentrators. The prepared polysaccharides were assessed by 1H NMR spectroscopy, providing general purity, fingerprinting, and structural information. This method may be used to efficiently screen polysaccharides in plants.

Advances in the chemical constituents, pharmacological properties and clinical applications of TCM formula Yupingfeng San

Yupingfeng San (YPFS) is a famous and commonly used traditional Chinese medicine (TCM) formula for the treatment of chronic obstructive pulmonary disease, asthma, respiratory tract infections, and pneumonia in China. It is composed of three Chinese herbs, including Astragali Radix, Atractylodis Macrocephalae Rhizoma and Saposhnikoviae Radix. In this review, the relevant references on YPFS were searched in the Web of Science, PubMed, China National Knowledge Infrastructure (CNKI), and other databases. Literatures published from 2000 to 2022 were screened and summarized. The constituents in YPFS could be classified into nine groups according to their structures, including flavonoids, saponins, essential oils, coumarins, lactones, amino acids, organic acids, saccharides, chromones and others. The importance of chemical constituents in YPFS were demonstrated for specific pathological processes including immunoregulatory, anti-inflammatory, anti-tumor and pulmonary diseases. This article systematically reviewed the up-to-date information on its chemical compositions, pharmacology and safety, that could be used as essential data and reference for clinical applications of YPFS.

Plant metabolomics: a new strategy and tool for quality evaluation of Chinese medicinal materials

The present quality control method of Chinese medicinal materials (CMM) has obvious deficiency, which cannot be compatible with the multi-target and multi-component characteristics and production process of CMM. Plant metabolomics with a huge impetus to comprehensively characterize the metabolites and clarify the complexity and integrity of CMM, has been widely used in the research of CMM. This article comprehensively reviewed the application of plant metabolomics in the quality control of CMM. It introduced the concept, technique, and application examples, discussed the prospects, limitations, improvements of plant metabolomics. MS and NMR, as important techniques for plant metabolomics, are mainly highlighted in the case references. The purpose of this article is to clarify the advantage of plants metabolomics for promoting the optimization of the CMM quality control system and proposing a system approach to realize the overall quality control of CMM based on plant metabolomics combined with multidisciplinary method.

Enhancement of the flavone contents of Scutellaria baicalensis hairy roots via metabolic engineering using maize Lc and Arabidopsis PAP1 transcription factors

Baicalin, baicalein, and wogonin are valuable natural flavonoid compounds produced by Scutellaria baicalensis. In this study, we showed that the maize transcription factor Lc can enhance the production of these three flavonoids in hairy root cultures of S. baicalensis by comprehensively upregulating flavonoid biosynthesis pathway genes (SbPAL1, SbC4H, and Sb4CL) and baicalein 7-O-glucuronosyltransferase (UBGAT), ultimately yielding total flavonoid contents of up to 80.5 ± 6.15 mg g^-1 dry weight, which was 322% greater than the average value of total flavonoid contents produced by three GUS-overexpressing lines. Similarly, the Arabidopsis transcription factor PAP1 was found to enhance flavonoid accumulation by upregulating SbPAL1, SbPAL2, SbPAL3, SbC4H, Sb4CL, SbCHI, and UBGAT, ultimately yielding total flavonoid contents of up to 133 ± 7.66 mg g^-1 dry weight, which was 532% greater than the average value of total flavonoid contents produced by three GUS-overexpressing lines. These findings indicate that metabolic engineering in S. baicalensis can be achieved using Agrobacterium rhizogenes-mediated transformation and that the production of baicalin, baicalein, and wogonin can be enhanced via the overexpression of ZmLc and AtPAP1 in hairy root cultures. These results also indicate that ZmLc and AtPAP1 can be used as positive regulators of the flavonoid biosynthetic pathway of S. baicalensis hairy root cultures.

New challenges for efficient usage of Sargassum fusiforme for ruminant production

Sargassum fusiforme, which is a type of brown algae, can provide fiber and minerals to ruminant diets. In this study, dried S. fusiforme was tested in vitro at four different doses 1, 3, 5, and 10% of the total ration for its effect on ruminal fermentation characteristics, and gas profiles when incubated for 72 h. At a level of 1 and 10%, S. fusiforme supplementation augmented total volatile fatty acid (VFA) concentrations compared to that with 0% supplementation. In addition, total gas, methane, and carbon dioxide emissions significantly decreased at 3 and 24 h of incubation at this dose. An in situ trial was performed for 72 h with S. fusiforme to evaluate it as a potential feed ingredient by comparing its degradation parameters with timothy hay (Phleum pretense). 1H nuclear magnetic resonance spectroscopy profiling was used to identify and quantify metabolites of S. fusiforme. Mannitol, guanidoacetate and ethylene glycol were largely accumulated in S. fusiforme. Moreover, nutritious minerals for feed ingredients were present in S. fusiforme. Whereas a high concentration of arsenic was found in S. fusiforme, it was within the allowable limit for ruminants. Our results suggest that S. fusiforme could represent an alternative, renewable feed ingredient for ruminant diets, with nutritional, as well as environmental, benefits.

Metabolomics comparison of rumen fluid and milk in dairy cattle using proton nuclear magnetic resonance spectroscopy

Objective

The metabolites that constitute the rumen fluid and milk in dairy cattle were analyzed using proton nuclear magnetic resonance (¹H-NMR) spectroscopy and compared with the results obtain for other dairy cattle herds worldwide. The aim was to provide basic dataset for facilitating research on metabolites in rumen fluid and milk.

Methods

Six dairy cattle were used in this study. Rumen fluid was collected using a stomach tube, and milk was collected using a pipeline milking system. The metabolites were determined by ¹H-NMR spectroscopy, and the obtained data were statistically analyzed by principal component analysis, partial least squares discriminant analysis, variable importance in projection scores, and metabolic pathway data using Metaboanalyst 4.0.

Results

The total numbers of metabolites in rumen fluid and milk were measured to be 186 and 184, and quantified as 72 and 109, respectively. Organic acid and carbohydrate metabolites exhibited the highest concentrations in rumen fluid and milk, respectively. Some metabolites that have been associated with metabolic diseases (acidosis and ketosis) in cows were identified in rumen fluid, and metabolites associated with ketosis, somatic cell production, and coagulation properties were identified in milk.

Conclusion

The metabolites measured in rumen fluid and milk could potentially be used to detect metabolic diseases and evaluate milk quality. The results could also be useful for metabolomic research on the biofluids of ruminants in Korea, while facilitating their metabolic research.

A comparative study between Chinese propolis and Brazilian green propolis: metabolite profile and bioactivity

Among different types, Chinese propolis (ChPs) and Brazilian green propolis (BrGPs) have been shown to contain multi-functional properties. Despite extensive research in the field, reports comparing propolis from different geographical areas are still limited, compromising our current understanding of the potential therapeutic effect associated with propolis and its derived compounds. Herein, a comparative study between ChPs and BrGPs including their metabolite profile and bioactivities was performed. Interestingly, even when ChPs and BrGPs showed similar anti-inflammatory potential, our results showed that they contained very different levels of ethanol extract, total flavonoids and total phenolic acids and in fact, LC-MS metabolic profiling and pattern recognition could effectively distinguish ChPs and BrGPs. Moreover, all the propolis samples tested showed good anti-oxidant activity and no significant difference of free radical scavenging capacity existed between ChPs and BrGPs. In conclusion, ChPs and BrGPs have a distinct chemome, but their antioxidant and anti-inflammatory activities are similar.

Chitosan promoting formononetin and calycosin accumulation in Astragalus membranaceus hairy root cultures via mitogen-activated protein kinase signaling cascades

Chitosan, behaving as a potent biotic elicitor, can induce plant defense response with the consequent enhancement in phytoalexin accumulation. Accordingly, chitosan elicitation was conducted to promote the production of two phytoalexins, i.e. formononetin and calycosin (also known as health-promoting isoflavones), in Astragalus membranaceus hairy root cultures (AMHRCs). Compared with control, 12.45- and 6.17-fold increases in the yields of formononetin (764.19 ± 50.81 μg/g DW) and calycosin (611.53 ± 42.22 μg/g DW) were obtained in 34 day-old AMHRCs treated by 100 mg/L of chitosan for 24 h, respectively. Moreover, chitosan elicitation could cause oxidative burst that would induce the expression of genes (MPK3 and MPK6) related to mitogen-activated protein kinase signaling (MAPK) cascades, which contributed to the transcriptional activation of pathogenesis-related genes (β-1,3-glucanase, Chitinase, and PR-1) and eight biosynthesis genes involved in the calycosin and formononetin pathway. Overall, the findings in this work not only highlight a feasible chitosan elicitation practice to enhance the in vitro production of two bioactive isoflavones for nutraceutical and food applications, but also contribute to understanding the phytoalexin biosynthesis in response to chitosan elicitation.

Discrimination of Polygonatum species and identification of novel markers using (1) H NMR- and UPLC/Q-TOF MS-based metabolite profiling

BACKGROUND

Rhizomes of Polygonatum species are commonly used as herbal supplements in Asia. They have different medicinal effects by species but have been misused and mixed owing to their similar taste and smell. Therefore accurate and reliable analytical methods to discriminate between Polygonatum species are required.

RESULTS

In this study, global and targeted metabolite profiling using (1) H nuclear magnetic resonance ((1) H NMR) spectroscopy and ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF MS) was applied to discriminate between different Polygonatum species. Partial least squares discriminant analysis (PLS-DA) models were used to classify and predict species of Polygonatum. Cross-validation derived from PLS-DA revealed good predictive accuracy. Polygonatum species were classified into unique patterns based on K-means clustering analysis. 4-Hydrobenzoic acid and trigonelline were identified as novel marker compounds and quantified accurately.

CONCLUSION

The results demonstrate that metabolite profiling approaches coupled with chemometric analysis can be used to classify and discriminate between different species of various herbal medicines. © 2015 Society of Chemical Industry.

Comparison of Two Different Astragali Radix by a ¹H NMR-Based Metabolomic Approach

Astragali Radix (AR) is a commonly used herbal drug in traditional chinese medicine and is widely used for the treatment of diabetes, cardiovascular diseases, nephropathy, and neuropathy. The main source of AR in China is the dried root of Astragalus membranaceus var. mongholicus (Bge.) Hsiao, and both cultivated and wild ARs are used clinically. A systematic comparison of cultivated AR (GS-AR) and wild AR (SX-AR) should be performed to ensure the clinical efficacy and safety. In this study, the chemical composition of the two different ARs, which were collected in the Shanxi (wild) and Gansu (cultivated) provinces, were compared by NMR-based metabolic fingerprint coupled with multivariate analysis. The SX-AR- and GS-AR-induced metabolic changes in the endogenous metabolites in mice were also compared. The results showed that SX-AR and GS-AR differed significantly not only in the primary metabolites but also in the secondary metabolites. However, alterations among the endogenous metabolites in the serum, lung, liver, and spleen were relatively small. This study provided a novel and valuable method for the evaluation of the consistency and diversity of herbal drugs, and further studies should be conducted on the difference in polysaccharides as well as the biological effects between the two kinds of AR.

Combining DI-ESI-MS and NMR datasets for metabolic profiling

Metabolomics datasets are commonly acquired by either mass spectrometry (MS) or nuclear magnetic resonance spectroscopy (NMR), despite their fundamental complementarity. In fact, combining MS and NMR datasets greatly improves the coverage of the metabolome and enhances the accuracy of metabolite identification, providing a detailed and high-throughput analysis of metabolic changes due to disease, drug treatment, or a variety of other environmental stimuli. Ideally, a single metabolomics sample would be simultaneously used for both MS and NMR analyses, minimizing the potential for variability between the two datasets. This necessitates the optimization of sample preparation, data collection and data handling protocols to effectively integrate direct-infusion MS data with one-dimensional (1D) 1H NMR spectra. To achieve this goal, we report for the first time the optimization of (i) metabolomics sample preparation for dual analysis by NMR and MS, (ii) high throughput, positive-ion direct infusion electrospray ionization mass spectrometry (DI-ESI-MS) for the analysis of complex metabolite mixtures, and (iii) data handling protocols to simultaneously analyze DI-ESI-MS and 1D 1H NMR spectral data using multiblock bilinear factorizations, namely multiblock principal component analysis (MB-PCA) and multiblock partial least squares (MB-PLS). Finally, we demonstrate the combined use of backscaled loadings, accurate mass measurements and tandem MS experiments to identify metabolites significantly contributing to class separation in MB-PLS-DA scores. We show that integration of NMR and DI-ESI-MS datasets yields a substantial improvement in the analysis of neurotoxin involvement in dopaminergic cell death.

Investigation of chemomarkers of astragali radix of different ages and geographical origin by NMR profiling

Astragalus roots from Astragalus membranaceus Bunge or Astragalus membranaceus var. mongholicus (Bunge) Hsiao are among the most popular traditional medicinal plants due to their diverse therapeutic uses based on their tonic, antinephritic, immunostimulant, hepatoprotectant, diuretic, antidiabetic, analgesic, expectorant and sedative properties. Currently, the herb is produced or cultivated in various sites, including 10 different locations in China with very diverse environmental conditions. These differences affect their metabolic pools and consequently their medicinal properties. The comparative metabolic profiling of plants of different geographical origins or ages could contribute to detect biomarkers for their quality control and thus guarantee the efficacy of the herbal medicines produced with this drug. In this paper nuclear magnetic resonance spectroscopy (NMR)-based metabolomics was applied for to plants of different origins and age for this purpose. The results of this study show that in the set of samples evaluated, age is more discriminating than geographical location. The quantity of individual flavonoids and some primary metabolites contributed most to this age differentiation. On the other hand, based on the analysis of orthogonal partial least square (OPLS) modeling, the marker metabolites for the geographical origin were saponins and isoflavonoids.

Tissue-specific distribution of ginsenosides in different aged ginseng and antioxidant activity of ginseng leaf

The aim of this study was to systematically evaluate the effect of the cultivation year on the quality of different ginseng tissues. Qualitative and quantitative analyses of ginsenosides were conducted using a UPLC-UV-MS method. Eight main ginsenosides in three tissues (leaf, rhizome and main root) and four parts (periderm, phloem, cambium and xylem) of ginseng aged from 1 to 13 years were determined using a UPLC-PDA method. Additionally, the antioxidant capacities of ginseng leaves were analyzed by the DPPH, ABTS and HRSA methods. It was found that the contents of ginsenosides increased with cultivation years, causing a sequential content change of ginsenosides in an organ-specific manner: leaf > rhizome > main root. The ratio between protopanaxatriol (PPT, Rg₁, Re and RF) and protopanaxadiol (PPD, Rb₁, Rb₂, RC and Rd) in the main root remained stable (about 1.0), while it increased in leaf from 1.37 to 3.14 and decreased in the rhizome from 0.99 to 0.72. The amount of ginsenosides accumulated in the periderm was 45.48 mg/g, which was more than twice as high compared with the other three parts. Furthermore, the antioxidant activities of ginseng leaves were measured as Trolox equivalents, showing that antioxidant activity increased along with time of cultivation. The results show that the best harvest time for shizhu ginseng is the fifth year of cultivation, and the root and rhizome could be used together within seven planting years for their similar PPT/PPD level. Besides, the quality of the ginseng products would be enhanced with the periderm. The ginseng leaf is rich in ginsenosides and has potential application for its antioxidant capacity.

Profiling convoluted single-dimension proton NMR spectra: a Plackett-Burman approach for assessing quantification error of metabolites in complex mixtures with application to cell culture

Single-dimension hydrogen, or proton, nuclear magnetic resonance spectroscopy (1D-(1)H NMR) has become an attractive option for characterizing the full range of components in complex mixtures of small molecular weight compounds due to its relative simplicity, speed, spectral reproducibility, and noninvasive sample preparation protocols compared to alternative methods. One challenge associated with this method is the overlap of NMR resonances leading to "convoluted" spectra. While this can be mitigated through "targeted profiling", there is still the possibility of increased quantification error. This work presents the application of a Plackett-Burman experimental design for the robust estimation of precision and accuracy of 1D-(1)H NMR compound quantification in synthetic mixtures, with application to mammalian cell culture supernatant. A single, 20 sample experiment was able to provide a sufficient estimate of bias and variability at different metabolite concentrations. Two major sources of bias were identified: incorrect interpretation of singlet resonances and the quantification of resonances from protons in close proximity to labile protons. Furthermore, decreases in measurement accuracy and precision could be observed with decreasing concentration for a small fraction of the components as a result of their particular convolution patterns. Finally, the importance of a priori concentration estimates is demonstrated through the example of interpreting acetate metabolite trends from a bioreactor cultivation of Chinese hamster ovary cells expressing a recombinant antibody.