Metabolic differentiations of Pueraria lobata and Pueraria thomsonii using 1H NMR spectroscopy and multivariate statistical analysis

Non-destructive prediction of isoflavone and starch by hyperspectral imaging and deep learning in Puerariae Thomsonii Radix

Accurate assessment of isoflavone and starch content in Puerariae Thomsonii Radix (PTR) is crucial for ensuring its quality. However, conventional measurement methods often suffer from time-consuming and labor-intensive procedures. In this study, we propose an innovative and efficient approach that harnesses hyperspectral imaging (HSI) technology and deep learning (DL) to predict the content of isoflavones (puerarin, puerarin apioside, daidzin, daidzein) and starch in PTR. Specifically, we develop a one-dimensional convolutional neural network (1DCNN) model and compare its predictive performance with traditional methods, including partial least squares regression (PLSR), support vector regression (SVR), and CatBoost. To optimize the prediction process, we employ various spectral preprocessing techniques and wavelength selection algorithms. Experimental results unequivocally demonstrate the superior performance of the DL model, achieving exceptional performance with mean coefficient of determination (R2) values surpassing 0.9 for all components. This research underscores the potential of integrating HSI technology with DL methods, thereby establishing the feasibility of HSI as an efficient and non-destructive tool for predicting the content of isoflavones and starch in PTR. Moreover, this methodology holds great promise for enhancing efficiency in quality control within the food industry.

Spatially resolved metabolomics combined with bioactivity analyses to evaluate the pharmacological properties of two Radix Puerariae species

ETHNOPHARMACOLOGICAL RELEVANCE

P. lobata and P. thomsonii are medicinal plants with similar pharmacological functions but different therapeutic effects. A novel method is presented herein to investigate metabolites in terms of their distribution and qualification, quantification is necessary to elucidate the different therapeutic effects of the two Puerariae species.

AIM OF THE STUDY

The aim of the present study was to perform spatially resolved metabolomics combined with bioactivity analyses to systematically compare the metabolite differences in P. lobata and P. thomsonii by distribution, qualification, quantification, and biological activity to evaluate their pharmacological properties.

MATERIALS AND METHODS

Air flow-assisted desorption electrospray ionization-mass spectrometry imaging (AFADESI-MSI) was performed to characterize the differences in the metabolite distributions of P. lobata and P. thomsonii. Further qualitative and quantitative analyses of the differential metabolites were performed using liquid chromatography-mass spectrometry (LC-MS). Biological activities correlated with the differences in the metabolites were validated by MTT assays.

RESULTS

Some metabolites showed complementary distributions of the phloem and xylem in the two species, saccharide, vitamin, and inosine levels were higher in the phloem of P. thomsonii but higher in the xylem of P. lobata. The 3'-hydroxyl puerarin level was higher in the xylem of P. thomsonii but higher in the phloem of P. lobata. Qualitative and quantitative analyses of the metabolites revealed a total of 52 key differential metabolites. MTT assays showed that daidzein, daidzin, puerarin, ononin, genistin, formononetin, 3'-hydroxy puerarin, 3'-methoxy puerarin, mirificin, and 3'-methoxy daidzin exerted protective effects on H9c2 cells against hypoxia/reoxygenation injury. P. lobata extracts exhibited a significantly better protective efficacy than P. thomsonii extracts.

CONCLUSIONS

In this study, AFADESI-MSI combined with LC-MS and biological activities comprehensively elucidated metabolite differences in the distribution, qualification, quantification, and pharmacological properties of P. lobata and P. thomsonii. The results of this study could provide a novel strategy for species identification and quality assessment of similar Chinese herbal medicines.

The chemistry and activity-orientedcharacterization of isoflavones difference between roots of Pueraria lobata and P. thomsonii guided by feature-based molecular networking

Isoflavones are important chemical components in Pueraria species with various biological activities. This study proposed an integrated strategy combining feature-based molecular networking (FBMN), chemometrics and activity evaluation for isoflavone analysis in the roots of P. lobate (PLR) and P. thomsonii (PTR). Based on the strategy, a total of 68 isoflavones were annotated in the two Pueraria species, and 11 significant difference isoflavones between PLR and PTR were identified by chemometric methods. Additionally, the correlation coefficient between the characteristic isoflavones and hypoglycemic activity were calculated, and 7 isoflavones were further confirmed as bioactive marker compounds. This approach provided guidance for the discovery of active markers among different products.

Comparative analysis of the medicinal and nutritional components of different varieties of Pueraria thomsonii and Pueraria lobata

Pueraria thomsonii and Pueraria lobata are important medicinal plants with unique chemical compositions that are widely used in traditional Chinese medicine. To compare the nutritional and medicinal profiles of these two species, we analyzed the flavonoid, dietary fiber, total starch, and crude protein contents of one P. lobata and three P. thomsonii varieties using ultra-performance liquid chromatography-tandem mass spectrometry, enzyme weight, acid hydrolysis, and Kjeldahl methods. Furthermore, we used principal component analysis and hierarchical clustering heatmap analysis to separate the data obtained from the P. thomsonii and P. lobata samples. We detected 279 flavonoid compounds in the two Pueraria species, including 90 isoflavones and 78 flavonoids. A large proportion of isoflavones and flavonoids were more abundant in P. lobata than in P. thomsonii. The total starch content was significantly higher in P. thomsonii than in P. lobata. By contrast, the soluble dietary fiber, insoluble dietary fiber, and crude protein contents were substantially lower in P. thomsonii than in P. lobata. Taken together, our results demonstrate that P. lobata is better suited for use as a medicine, whereas P. thomsonii is better suited as an edible food, and provide a theoretical foundation for developing P. thomsonii and P. lobata germplasm resources.

Tailoring enhanced production and identification of isoflavones in the callus cultures of Pueraria thomsonii Benth and its model verification using response surface methodology (RSM): a combined in vitro and statistical optimization

Background

Scientifically, isoflavones from Pueraria thomsonii Benth possess diverse pharmacological activities and have been used to treat various diseases. In vitro propagation of callus has contributed to the reliability for large-scale production of target compounds. However, the factors affecting the biosynthesis of major isoflavones daidzin, puerarin and daidzein in the callus culture of P. thomsonii are still not known. Therefore, we aimed to enhance the in vitro production of daidzin, puerarin and daidzein by optimizing three independent factors such as temperature, NAA and 6-BA concentrations.

Results

Our findings showed that the optimal concentrations for in vitro biomass production and efficient synthesis of puerarin, daidzin and daidzein were found to be 0.158%, 0.463% and 0.057%, respectively. In addition, the HPLC fingerprint with chemo-metrics analysis was constructed by linear regression of the puerarin, daidzin and daidzein which was found to be in the range of 1.0–36.0, 5.0–72.0 and 1.0–15.0 mg/mL and the LODs and LOQs were found to be 0.15, 0.52, 0.35 and 0.28, 1.50, 0.50 mg/mL for puerarin, daidzin and daidzein, respectively. Surprisingly, our results were also in agreement with the concentration obtained from the model verification for optimal and efficient production of puerarin, daidzin and daidzein which was found to be 0.162%, 0.458% and 0.049%, respectively.

Conclusions

In summary, our present investigation provides new insights that could facilitate the enhanced production of valuable isoflavones in P. thomsonii using plant cell cultures treated with appropriate elicitor combinations and temperature. As far as the authors are concerned, this is the first report on production of daidzin, puerarin and daidzein at higher yield at laboratory level for a wide range of applications in future food, medicinal and pharmaceutical companies.

Chromosomal-level genome and multi-omics dataset of Pueraria lobata var. thomsonii provide new insights into legume family and the isoflavone and puerarin biosynthesis pathways

Pueraria lobata var. thomsonii (hereinafter abbreviated as Podalirius thomsonii), a member of legumes, is one of the important traditional Chinese herbal medicines, and its puerarin extraction is widely used in health and pharmaceutical industry. Here, we assembled a high-quality genome of P. thomsonii using long-read single-molecule sequencing and Hi-C technologies. The genome assembly is approximately 1.37 Gb in size and consists of 5145 contigs with a contig N50 of 593.70 Kb, further clustered into 11 pseudochromosomes. The genome structural annotation resulted in about 869.33 Mb (about 62.70% of the genome) repeat regions and 45 270 protein-coding genes. Genome evolution analysis revealed that P. thomsonii is most closely related to soybean and underwent two ancient whole-genome duplication events, one was in the common ancestor shared by legume species, the other occurred independently at around 7.2 million years ago after its specification. A total of 2373 gene families were found unique in P. thomsonii comparing to five other legume species. Genes and metabolites related to puerarin content in tuberous tissues were characterized. A total of 572 genes upregulated in the puerarin biosynthesis pathway were identified, and 235 candidate genes were further enriched by omics data. Furthermore, we identified 6 8-C-glucosyltransferase (8-C-GT) candidate genes significantly involved in puerarin metabolism. Our study filled in a key genomic gap in legume family, and provided valuable multi-omic resources for the genetic improvement of P. thomsonii.

NMR technique and methodology in botanical health product analysis and quality control

Botanicals have played an important role in maintaining human health and well-being throughout history. During the past few decades in particular, the use of botanical health products has gained more popularity. Whereas, quality, safety and efficacy concerns have continuously been critical issues due to the intrinsic chemical complexity of botanicals. Chemical analytical technologies play an imperative role in addressing these issues. Nuclear magnetic resonance (NMR) spectroscopy has proven to be a powerful and useful tool for the investigation of botanical health products. In this review, NMR techniques and methodologies that have been successfully applied to the research and development of botanical health products in all stages, from plants to products, are discussed and summarized. Furthermore, applications of NMR together with other analytical techniques in a variety of domains of botanical health products investigation, such as plant species differentiation, adulteration detection, and bio-activity evaluation, are discussed and illustrated with typical examples. This article provides an overview of the potential uses of NMR techniques and methodologies in an attempt to further promote their recognition and utilization in the field of botanical health products analysis and quality control.

Simultaneous quantitation of glycyrrhetic acid and puerarin in plasma using ultra flow liquid chromatography tandem mass spectrometry and application in a pharmacokinetics study in healthy and alcoholic liver injury rats

A rapid, sensitive, and accurate ultra flow liquid chromatography tandem mass spectrometry (UFLC-MS/MS ) method was developed and validated for simultaneous quantitation of glycyrrhetic acid and puerarin in plasma derived from healthy and alcoholic liver injury rats. Plasma samples from healthy and model rats were deproteinated with methanol using liquiritin as an internal standard. Chromatography separation was performed by a Waters BEH (ethylene-bridged hybrid) C₁₈ column (2.1 × 50 mm; 1.7 μm) using a gradient elution from acetonitrile and water (containing 0.1% formic acid) and at a flow rate of 0.4 mL/min. Quantitation was performed on a Triple Quad 4500 tandem mass spectrometer coupled with an electrospray ionization source in negative multiple reaction monitoring mode. Specificity, carryover, dilution integrity, recovery, linearity, precision and accuracy, matrix effect, and stability were within acceptable limits. The newly established method was successfully applied to a pharmacokinetics study to investigate glycyrrhetic acid and puerarin in healthy and alcoholic liver injury rats.

NMR-Based Plant Metabolomics in Nutraceutical Research: An Overview

Few topics are able to channel the interest of researchers, the public, and industries, like nutraceuticals. The ever-increasing demand of new compounds or new sources of known active compounds, along with the need of a better knowledge about their effectiveness, mode of action, safety, etc., led to a significant effort towards the development of analytical approaches able to answer the many questions related to this topic. Therefore, the application of cutting edges approaches to this area has been observed. Among these approaches, metabolomics is a key player. Herewith, the applications of NMR-based metabolomics to nutraceutical research are discussed: after a brief overview of the analytical workflow, the use of NMR-based metabolomics to the search for new compounds or new sources of known nutraceuticals are reviewed. Then, possible applications for quality control and nutraceutical optimization are suggested. Finally, the use of NMR-based metabolomics to study the impact of nutraceuticals on human metabolism is discussed.

13C-NMR-based metabolic fingerprinting of Citrus-type crude drugs

Five Citrus-type crude drugs (40 samples) were classified using ¹³C-NMR spectra-based metabolomics. The following eight metabolites were identified from the loading plots of multivariate analysis of the ¹³C-NMR spectra; naringin, neohesperidin, narirutin, synephrine, sucrose, α-glucose, β-glucose, and limonene. ¹³C-NMR spectra-based metabolic fingerprinting is a promising strategy for classifying crude drugs.

Authentic compound-free strategy for simultaneous determination of primary coumarins in Peucedani Radix using offline high performance liquid chromatography-nuclear magnetic resonance spectroscopy-tandem mass spectrometry

Herein, a strategy is proposed for the simultaneous determination of primary coumarins in Peucedani Radix (Chinese name: Qianhu). The methodology consists of three consecutive steps: 1) Semi-preparative LC in combination with a home-made automated fraction collection module to fragment the universal metabolome standard into ten fractions (Frs. I-X); 2) LC-accurate MS/MS and quantitative ¹H NMR spectroscopy conducted in parallel to acquire the qualitative and quantitative data of each fraction; 3) Robust identification and quantification of components by use of LC coupled to multiple reaction monitoring. In this final step, the most significant fractions (Frs. III-X) were pooled to serve as the pseudo-mixed standard solution. Meticulous online parameter optimization was performed to obtain the optimal parameters, including ion transitions and collision energies. Concerns were particularly paid onto pursuing the parameters being capable of monitoring regio-specific isomers, notably praeruptorin E vs. 3'-isovaleryl-4'-angeloylkhellactone. The quantitative performance of the method was validated according to diverse assays. Eleven primary coumarins (1-11) were unambiguously identified and absolutely quantified, even though no external reference compound was used. Above all, the integrated strategy not only provides a feasible pipeline for the quality assessment of Peucedani Radix, but more importantly, shows the potential for authentic compound-free quantitative evaluation of traditional Chinese medicines.

A full solution for multi-component quantification-oriented quality assessment of herbal medicines, Chinese agarwood as a case

The quality of herbal medicines (HMs) is the prerequisite for their pronounced therapeutic outcomes in clinic, and multi-component (also known as quality markers, Q-markers) quantification has been widely emphasized as a viable means for quality evaluation. Because of the chemical diversity, the quality control practices are extensively dampened by four principal technical bottlenecks, including the lack of authentic compounds, large polarity span, extensive concentration range, and signal misrecognition for those potential Q-markers. An attempt to promote the potential of LC-MS/MS is made herein to cope with those obstacles and Chinese agarwood was employed as a case study. Firstly, a home-made fraction collector was introduced to automatically fragment the entire extract into a panel of fractions-of-interest. Secondly, quantitative ¹H-NMR was deployed to offset the LC-MS/MS potential towards in-depth chemical profiling each fraction, and those well-defined fractions were then pooled and combined with some accessible authentic compounds to generate the pseudo-mixed standard solution. Thirdly, serial improvements were conducted for LC-MS/MS measurements. Reversed phase LC and hydrophilic interaction LC were serially coupled in respond to the large polarity window, and online parameter optimization, response tailoring, as well as RRCEC (relative response vs. collision energy curve) matching were integrated in MS/MS domain to advance the quantitative confidences. Simultaneous determination was conducted for 26 components, in total, in Chinese agarwood after method validation. In particular, authentic compound-free quantification was achieved for eight 2-(2-phenylethyl)chromone derivatives. Above all, the strategy is a promising solution to completely tackle with the technical barriers toward Q-marker quantification-oriented quality control of Chinese agarwood, as well as other HMs.

Extraction of isoflavones from Puerariae lobata using subcritical water

As an alternative to organic solvents, subcritical water was employed for the first time as an effective solvent for the extraction of isoflavones from Puerariae lobata. Optimum experimental conditions for the extraction of the four main isoflavones were established by single factor experiments, and the optimum experimental conditions for total isoflavone extraction were established further by response surface methodology. With an extraction time of 45 min and a liquid/solid ratio of 1 : 20, the extraction yields of puerarin, 3′-methoxypuerarin, and daidzin reached maxima at extraction temperatures of 120 °C, 140 °C and 200 °C, respectively. Moreover, puerarin, 3′-methoxypuerarin and daidzin were degraded and produced various byproducts due to hydrothermal reactions at higher temperatures. The maximum extraction yields of the total isoflavones were obtained by response surface methodology (extraction time of 45 min, solid/liquid ratio of 1 : 15 and extraction temperature of 120 °C). Compared to conventional solvents, subcritical water utilized less solvent and required a shorter extraction time.

Four main isoflavones from Puerariae lobata were successfully extracted using subcritical water. Maximum yields of total isoflavones by response surface methodology were obtained.

Application of 1H NMR-based metabolomics for discrimination of different parts and development of a new processing workflow for Cistanche deserticola

Cistanche deserticola (CD) is one of the two authoritative source plants of Cistanches Herba, a well-known medicinal plant. Herein, ¹H NMR spectroscopy was employed to characterize the chemical profile and to distinguish the different parts, as well as to propose a new processing workflow for CD. Signal assignment was achieved by multiple one and two dimensional NMR spectroscopic techniques in combination with available databases and authentic compounds. The upper parts of the plant were distinguished from the lower parts by combining ¹H NMR spectroscopic dataset with multivariate statistical analysis. A new processing method that hyphenated steaming with freeze-drying, was demonstrated to be superior to either steaming coupled with oven-drying or direct freeze-drying via holistic ¹H NMR-based metabolomic characterization. Phenylethanoid glycosides, mainly echinacoside and acteoside, were screened out and confirmed as the chemical markers responsible for exhibiting the superiority of the new processing workflow, whereas serial primary metabolites, especially carbohydrates and tricarboxylic acid cycle metabolites, were found as the primary molecules governing the discrimination between the upper and lower parts of the plant. Collectively, ¹H NMR spectroscopy was demonstrated as a versatile analytical tool to characterize the chemical profile and to guide the in-depth exploitation of CD by providing comprehensive qualitative and quantitative information.

Metabolic discrimination of sea buckthorn from different Hippophaë species by 1H NMR based metabolomics

Sea buckthorn (Hippophaë; Elaeagnaceae) berries are widely consumed in traditional folk medicines, nutraceuticals, and as a source of food. The growing demand of sea buckthorn berries and morphological similarity of Hippophaë species leads to confusions, which might cause misidentification of plants used in natural products. Detailed information and comparison of the complete set of metabolites of different Hippophaë species are critical for their objective identification and quality control. Herein, the variation among seven species and seven subspecies of Hippophaë was studied using proton nuclear magnetic resonance (¹H NMR) metabolomics combined with multivariate data analysis, and the important metabolites were quantified by quantitative ¹H NMR (qNMR) method. The results showed that different Hippophaë species can be clearly discriminated and the important interspecific discriminators, including organic acids, L-quebrachitol, and carbohydrates were identified. Statistical differences were found among most of the Hippophaë species and subspecies at the content levels of the aforementioned interspecific discriminators via qNMR and one-way analysis of variance (ANOVA) test. These findings demonstrated that ¹H NMR-based metabolomics is an applicable and effective approach for simultaneous metabolic profiling, species differentiation and quality assessment.

The Progress of Metabolomics Study in Traditional Chinese Medicine Research

Traditional Chinese medicine (TCM) has played important roles in health protection and disease treatment for thousands of years in China and has gained the gradual acceptance of the international community. However, many intricate issues, which cannot be explained by traditional methods, still remain, thus, new ideas and technologies are needed. As an emerging system biology technology, the holistic view adopted by metabolomics is similar to that of TCM, which allows us to investigate TCM with complicated conditions and multiple factors in depth. In this paper, we tried to give a timely and comprehensive update about the methodology progression of metabolomics, as well as its applications, in different fields of TCM studies including quality control, processing, safety and efficacy evaluation. The herbs investigated by metabolomics were selected for detailed examination, including Anemarrhena asphodeloides Bunge, Atractylodes macrocephala Kidd, Pinellia ternate, etc.; furthermore, some valuable results have been obtained and summarized. In conclusion, although the study of metabolomics is at the early phase and requires further scrutiny and validation, it still provides bright prospects to dissect the synergistic action of multiple components from TCM. Overall, with the further development of analytical techniques, especially multi-analysis techniques, we expect that metabolomics will greatly promote TCM research and the establishment of international standards, which is beneficial to TCM modernization.

The relevance of pharmacognosy in pharmacological research on herbal medicinal products

As all medicines, herbal medicinal products are expected to be safe, effective, and of appropriate quality. However, regulations on herbal medicinal products vary from country to country, and herbal preparations do occur not only in the form of medicinal products but also as less strictly regulated product groups like dietary supplements. Therefore, it is not always easy for the consumers to discriminate high-quality products from low-quality products. On the other hand, herbal medicines have many special features that distinguish them from conventional medicinal products. Plants are complex multicomponent mixtures; in addition, their phytochemical composition is not constant because of inherent variability and a plethora of external influences. Therefore, the production process of an herbal medicinal product needs to be strictly monitored. First of all, the starting materials need to be correctly authenticated and free of adulterants and contaminants. During plant growth, many factors like harvest season and time, developmental stage, temperature, and humidity have a strong impact on plant metabolite production. Also, postharvest processing steps like drying and storage can significantly alter the phytochemical composition of herbal material. As the production of many phytopharmaceuticals includes an extraction step, the extraction solvent and conditions need to be optimized in order to enrich the bioactive constituents in the extract. The quality of finished preparations needs to be determined either on the basis of marker constituents or on the basis of analytical fingerprints. Thus, all production stages should be accompanied by appropriate quality assessment measures. Depending on the particular task, different methods need to be applied, ranging from macroscopic, microscopic, and DNA-based authentication methods to spectroscopic methods like vibrational spectroscopy and chromatographic and hyphenated methods like HPLC, GC-MS and LC-MS. Also, when performing pharmacological and toxicological studies, many features inherent in herbal medicinal products need to be considered in order to guarantee valid results: concerning in vitro studies, difficulties are often related to lacking knowledge of ADME characteristics of the bioactive constituents, nuisance compounds producing false positive and false negative results, and solubility problems. In in vivo animal studies, the route of administration is a very important issue. Clinical trials on herbal medicinal products in humans very often suffer from a poor reporting quality. This often hampers or precludes the pooling of clinical data for systematic reviews. In order to overcome this problem, appropriate documentation standards for clinical trials on herbal medicinal products have been defined in an extension of the CONSORT checklist. This article is part of a Special Issue entitled "Botanicals for Epilepsy".

Metabolic characterization of natural and cultured Ophicordyceps sinensis from different origins by 1H NMR spectroscopy

Ophicordyceps sinensis is a well-known traditional Chinese medicine and cultured mycelium is a substitute for wild O. sinensis. Metabolic profiles of wild O. sinensis from three geographical locations and cultivated mycelia derived from three origins were investigated using (1)H nuclear magnetic resonance (NMR) analysis combined with multivariate statistical analysis. A total of 56 primary metabolites were identified and quantified from O. sinensis samples. The principle component analysis (PCA) showed significant differences between natural O. sinensis and fermentation mycelia. Seven metabolites responsible for differentiation were screened out by orthogonal partial least squares discriminant analysis (OPLS-DA). The concentrations of mannitol, trehalose, arginine, trans-4-hydroxyproline, alanine and glucitol were significantly different between wild and cultured groups. The variation in metabolic profiling among artificial mycelia was greater than that among wild O. sinensis. Furthermore, wild samples from different origins were clearly distinguished by the levels of mannitol, trehalose and some amino acids. This study indicates that (1)H NMR-based metabolomics is useful for fingerprinting and discriminating O. sinensis of different geographical regions and cultivated mycelia of different strains. The present study provided an efficient approach for investigating chemical compositions and evaluating the quality of medicine and health food derived from O. sinensis.

Homolog-focused profiling of ginsenosides based on the integration of step-wise formate anion-to-deprotonated ion transition screening and scheduled multiple reaction monitoring

Homolog-focused profiling is a favored option to bridge targeted metabolomics toward non-targeted metabolomics. In current study, an attempt was made for the large-scale ginsenoside-specific analysis in ginseng (G) and American ginseng (AG). When formic acid (0.1%, v/v) was introduced as the mobile phase additive, formate anion-to-deprotonated ion transitions ([M+HCOO](-)>[M-H](-)) with an optimal collision energy (-32eV) could result in satisfactory responses for ginsenosides. Therefore, a step-wise multiple reaction monitoring (MRM)-based method employing [M+HCOO](-)>[M-H](-) ion pairs was constructed to screen ginsenosides among 501-1250u (for Q1) with a step-size of 2u, and MRM also served as a survey experiment to trigger enhanced product ion scans for MS(2) spectrum acquisition on a hybrid triple quadrupole-linear ion trap mass spectrometer; then, the identification of those observed ginsenosides was achieved on the basis of the well-defined mass cracking patterns for ginsenosides; afterwards, scheduled MRM was introduced for large-scale relatively quantitative analysis of all detected ginsenosides. Finally, comparative metabolomics were performed to differentiate G, AG, and their processed products. Method validation was carried out using thirteen authentic compounds. A total of 221 ginsenosides, among which 185 ones were annotated, were observed and relatively quantitated. All crude materials were obviously classified into groups I-III. Above all, the MRM-based homolog-focused profiling of ginsenosides could be used as a reliable tool to gain an in-depth view for ginsenoside-enriched herbal products.

Dynamics of phytoestrogen, isoflavonoids, and its isolation from stems of Pueraria lobata (Willd.) Ohwi growing in Democratic People's Republic of Korea

Four isoflavonoids were isolated from stems of Pueraria lobata (Willd.) Ohwi growing in Democratic People’s Republic of Korea and identified as daidzein (1), genistin (2), daidzin (3), and puerarin (4), structures, which were elucidated by means of spectroscopic analysis. Isoflavonoids were isolated using silica gel chromatography and purified with organic solvents. Isoflavonoid contents in P. lobata were determined using reliable high-performance liquid chromatography. The results indicated that the contents of puerarin and genistin in the roots are higher than those in the stems (6.19% and 0.04% vs. 1.15% and 0.02%), whereas the stems have higher contents of daidzin and daidzein than the roots (3.17% and 0.06% vs. 1.72% and 0.05%). Accordingly, the root part of the plant is useful for the isolation of puerarin and the stem part for daidzin. This study suggests that the stem of P. lobata is useful as an alternative source of puerarin, daidzin, genistin, and daidzein. In addition, collection of the stem will not sacrifice the plant and thus is beneficial to the natural ecosystems.

Comparing morphological, chemical and anti-diabetic characteristics of Puerariae Lobatae Radix and Puerariae Thomsonii Radix

ETHNOPHARMACOLOGICAL RELEVANCE

Puerariae Lobatae Radix (PLR) and Puerariae Thomsonii Radix (PTR) are traditional Chinese medicines used for the treatment of diabetes and cardiovascular diseases. These two herbs are used interchangeably in clinical practice, even though they possess significantly different chemical profiles. In the case of Pueraria species, the misidentification is related to the multiple Chinese common names in clinical practice and variable pharmaceutical Latin names in different versions of the Pharmacopoeia of the People's Republic of China. In addition, there is lack of evidence demonstrating how the differences in the chemical profile would impact on the pharmacological activity of the two herbs. Therefore, the aim of this study was to compare the microscopic, phytochemical profiles and anti-diabetic activity of PLR and PTR so that the two species can be differentiated.

MATERIALS AND METHODS

The microscopic characteristics of the PLR and PTR were observed and measured by an optical microscope. The major compounds were quantified by ultra-performance liquid chromatography (UPLC) and total flavonoid content (TFC) colorimetric assay. The free radical scavenging capacity was assessed by 2,2-diphenyl-2-picrylhydrazyl (DPPH) antioxidant assays. Anti-diabetic activity was determined by the inhibition of porcine pancreatic α-amylase and rat intestinal α-glucosidase activities.

RESULTS

Microscopic results illustrated that the size of xylem vessels (PLR: 0.1390 ± 0.0184 mm; PTR: 0.0471 ± 0.0109 mm), number of fibre per bundle (PLR: 32.6800 ± 2.8780; PTR: 16.5900 ± 0.9982) and the size of fibre (PLR: 0.0075 ± 0.0003 mm(2); PTR: 0.0025 ± 0.0002 mm(2)) in PLR were significantly greater than that in PTR (p<0.01). PLR possessed a significantly lower total starch content (PLR: 0.5288 ± 1.2559 mg starch/g DM; PTR: 76.7954 ± 2.9905 mg starch/g DM) and total dietary fibre content (PLR: 4.2886 ± 0.3466 g/100g DM; PTR: 12.4148 ± 0.4541 g/100g DM) as compared to PTR. Isoflavonoids including puerarin, daidzin, genistin and daidzein were the major chemical constituents in both species. However, the average content of puerarin in PLR was found to be eleven times greater than that in PTR. Furthermore, the TFC, DPPH free radical scavenging capacity, anti-α-amylase and anti-α-glucosidase in the PLR extracts were 4.42, 4.91, 3.10 and 4.22 times greater than in the PTR extracts.

CONCLUSIONS

This study provides a comprehensive investigation on the two medicinal valuable Pueraria species and allows differences to be ascertained. This information can be used to update monographs which will help practitioners and dispensers differentiate the herbs. Further study on the interchangeable use of PLR and PTR in clinical practice is urgently warranted.