Recent analytical approaches in quality control of traditional Chinese medicines--a review

Immunostimulatory lipid nanoparticles from herbal medicine

Reproducibility is an important issue in biological characterization of drug candidates and natural products. It is not uncommon to encounter cases in which supposedly the same sample exhibits very different biological activities. During our characterization of macrophage-stimulatory lipids from herbal medicine, it was found that the potency of these lipids could vary substantially from experiment to experiment. Further analysis of this reproducibility issue led to the discovery of solvent-dependent nanoparticle formation by these lipids. While larger nanoparticles (approximately 100 nm) of these lipids showed modest macrophage-stimulatory activity, smaller nanoparticles (<10 nm) of the same lipids exhibited substantially higher potency. Thus, the study revealed an unexpected link between nanoparticle formation and macrophage-stimulatory activity of plant lipids. Although nanoparticles have been extensively studied in the context of vehicles for drug delivery, our finding indicates that drugs themselves can form nanoassemblies, and their biological properties may be altered by the way they assemble.

Simultaneous determination of fifteen constituents of jitai tablet using ultra high-performance liquid chromatography coupled with triple quadrupole electrospray tandem mass spectrometry

An ultra-high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (UHPLC-ESI-MS/MS) method was developed for simultaneous determination of fifteen constituents in Jitai tablet (JTT), a complex Traditional Chinese Medicine prescription (TCMP) used in treating opiate addiction. Benefitting from a small particle size (1.8 µm) C18 column, accelerated analysis with satisfactory resolution, sensitivity and selectivity were achieved in a single run within 7 min with linear gradient elution of acetonitrile-0.1% (v/v) formic acid in water. The analytical signal was obtained by multiple reaction monitoring transitions via electrospray ionization source operating in both positive and negative ionization mode. The approach was validated for linearity, sensitivity, precision, repeatability, stability and recovery. All analytes showed good linearity over a wide concentration range (r > 0.99). The method limits ranged from 0.03 ng/mL to 19.35 ng/mL which are sensitive enough for quality control studies. The developed method was successfully applied to the simultaneous determination of fifteen constituents in JTT. In conclusion, our experimental results demonstrate that UHPLC-ESI-MS/MS is a useful approach for the overall quality assessment of complex TCMPs.

Promotion of quality standard of herbal medicine by constituent removing and adding

To identify major active constituents and measure their levels in a typical medicinal herb-Rhizoma coptidis, we applied the concept of removing and adding, taking inspiration from functional genetic methods. As this herb has bacteriostatic properties and is used to treat bacterial diarrhea, we examined the effects of individual constituents (berberine, palmatine, coptisine, epiberberine, jateorrhizine and columbamine) on the growth of Shigella dysenteriae with microcalorimetry. The removing and adding procedures revealed that berberine and coptisine were the main antibacterial constituents of R. coptidis, with bacteriostatic activities of 54.10% and 39.75%, respectively. The relative levels of berberine and coptisine in R. coptidis were 8.08%-31.92% and 4.05%-14.45%, respectively. On the basis of whole effect, the method of constituents removing and adding, coupled with a bioassay, is a useful strategy to identify the active constituents and measure their levels in herbal medicines, which may provide reference to other natural products.

Quantitative analysis and fingerprint profiles for quality control of Fructus Schisandrae by gas chromatography: mass spectrometry

This paper describes a simple, rapid, and effective quality assessment method for Fructus Schisandrae by gas chromatography-mass spectrum (GC-MS). The method was established by using specific lignan fingerprint profiles and quantitation of characteristic compounds in this herbal medicine. The GC-MS fingerprints of 15 batches of Schisandra samples from different regions of China showed similar lignan profiles. Five peaks were selected as characteristic peaks, and all of these were identified by using GC-MS techniques. The relative retention times of these characteristic peaks in the GC-MS fingerprint were established as an important parameter for identification of Schisandra samples. Meanwhile, relative peak areas may be a feasible approach to discriminate the S. chinensis and S. sphenanthera. Finally, these pharmacologically active constituents in the titled plant, schisandrins A–C and schizandrols A and B, were quantitatively determined using a validated GC-MS method.

Chemometrics: A new scenario in herbal drug standardization

Chromatography and spectroscopy techniques are the most commonly used methods in standardization of herbal medicines but the herbal system is not easy to analyze because of their complexity of chemical composition. Many cutting-edge analytical technologies have been introduced to evaluate the quality of medicinal plants and significant amount of measurement data has been produced. Chemometric techniques provide a good opportunity for mining more useful chemical information from the original data. Then, the application of chemometrics in the field of medicinal plants is spontaneous and necessary. Comprehensive methods and hyphenated techniques associated with chemometrics used for extracting useful information and supplying various methods of data processing are now more and more widely used in medicinal plants, among which chemometrics resolution methods and principal component analysis (PCA) are most commonly used techniques. This review focuses on the recent various important analytical techniques, important chemometrics tools and interpretation of results by PCA, and applications of chemometrics in quality evaluation of medicinal plants in the authenticity, efficacy and consistency.

Sparse partial-least-squares discriminant analysis for different geographical origins of Salvia miltiorrhiza by (1) H-NMR-based metabolomics

INTRODUCTION

(1) H nuclear magnetic resonance (NMR) spectroscopy has clear advantages in respect of detecting various primary and secondary metabolites in plants simultaneously, non-targeted and non-destructively.

OBJECTIVE

To establish a method for detecting both primary and secondary metabolites in Salvia miltiorrhiza and screening potential geographical biomarkers effectively.

METHODS

Primary and secondary metabolites of S. militiorrhiza were detected and identified by (1) H-NMR fingerprint. Sparse partial-least-squares discriminant analysis (sPLS-DA) was undertaken for classification and variable selection in a one-step procedure and the classification error rates were implemented to estimate the cluster validation of sPLS-DA. Potential candidate metabolites by characterised different geographical origins of S. miltiorrhiza were identified according to the sparse loading vectors. The levels of these metabolites were quantified and evaluated by Kruskal-Wallis tests and also showed significant difference.

RESULTS

Twenty-six primary and secondary metabolites were identified in samples from different regions. The results suggest that malonate and succinate can be possibly recognised as the key markers for discriminating the geographical origin of S. miltiorrhiza based on the regulation and influence on the root respiratory rates of plants.

CONCLUSION

(1) H-NMR metabolic profiling combination with PLS-DA provided a very efficient and visualised representation of similarities and dissimilarities between S. miltiorrhiza samples.

The Fourier transform infrared spectra of the key organs derived from Kidney (Shen)-yang deficiency syndrome mice

OBJECTIVE

To explore an approach to rapidly and accurately identify the compounds as biomarkers of Chinese medicine (CM) syndromes.

METHOD

The Fourier transform infrared (FT-IR) spectrometry was applied to investigate the characteristic components of a mice model of Kidney (Shen)-yang deficiency syndrome (KDS), and the remedial effect of a typical CM formula Shenqi Pill (). Thirty-six females and 18 males of Balb/c mice were randomly divided into KDS, Shenqi or control group. The females and males of the same group freely were mated for 96 h, and the males were taken out and only the female mice were raised. Females of the KDS group were threatened by a ferocious cat every other day for 14 d. After delivery, the KDS, or gestational threatened, offspring were raised at standard condition for 11 weeks. Then 10 male offspring were randomly selected, anaesthetized and their representative organs, i.e. testes, kidneys, lungs and feet were collected, for the FT-IR scan. Mice of the Shenqi group were intragastric administered Shenqi Pill; while mice in the KDS and control groups were given the same volume of saline.

RESULTS

The attenuated birth outcomes of the KDS group were displayed. The remarkable FT-IR differences of all organs between KDS mice and healthy control were mainly at 1,735-1,745 cm(-1) (indicating the increased levels of lipids) and at 1,640-1,647 cm(-1) and 1,539-1,544 cm(-1) (displaying the decreased proteins). No statistic FT-IR difference between Shenqi and control mice was observed.

CONCLUSION

In accordance with major traits of KDS, prenatal stress extensively impaired the building up of proteins and resulting in the excessive lipid storage, and FT-IR could effectively identify the biomarkers of KDS.

Methods for Extraction and Determination of Phenolic Acids in Medicinal Plants: A Review

Phenolic acids constitute a group of potentially immunostimulating compounds. They occur in all medicinal plants and are widely used in phytotherapy and foods of plant origin. In recent years, phenolic acids have attracted much interest owing to their biological functions. This paper reviews the extraction and determination methods of phenolic acids in medicinal plants over the last 10 years. Although Soxhlet extraction and ultrasonic assisted extraction (UAE) are commonly used for the extraction of phenolic acids from plant materials, alternative techniques such as supercritical fluid extraction (SFE), and accelerated solvent extraction (ASE) can also be used. After extraction, phenolic acids are determined usually by liquid chromatography (LC) owing to the recent developments in this technique, especially when it is coupled with mass spectrometry (MS). Also detection systems are discussed, including UV-Vis, diode array, electrochemical and fluorimetric. Other popular techniques for the analysis of this group of secondary metabolites are gas chromatography coupled with mass spectrometry (GC-MS) and capillary electrophoresis (CE).

Improved quality control method for prescriptions of Polygonum capitatum through simultaneous determination of nine major constituents by HPLC coupled with triple quadruple mass spectrometry

As a traditional Miao-nationality medicinal plant, Polygonum capitatum has been used in clinical practice for several thousand years. Its prescriptions, including three dosage forms: granules, capsule and tablet are known by the brand name Relinqing^® and have played an indispensable role in the treatment of urinary system infection, pyelonephritis and kidney stones. However, no study about the comprehensive quality evaluation of Relinqing^® has been reported. In the present paper, a method for the simultaneous determination of nine major compounds in three dosage forms of Relinqing^® using HPLC coupled with triple quadrupole mass spectrometry (HPLC-QQQ MS) was established to comprehensively evaluate their quality. The nine compounds, including four phenolic acids, four flavonoids and a lignin, were analyzed with acceptable linear regression relationship (r², 0.9923–0.9992), precision (RSD, 1.25%–2.78%), repeatability (RSD, 2.05%%–3.47%), stability (RSD, 1.84%–3.72%) and recovery (93.60%–108.54%, RSD ≤ 3.67%). The present study fills the gap in the multivariate quality control of Relinqing^® and provides a valuable reference for quality standards and dosage reforming of this traditional Chinese medicine.

Metabolomic characterization of rhubarb species by capillary electrophoresis and ultra-high-pressure liquid chromatography

This study developed CE and ultra-high-pressure LC (UHPLC) methods coupled with UV detectors to characterize the metabolomic profiles of different rhubarb species. The optimal CE conditions used a BGE with 15 mM sodium tetraborate, 15 mM sodium dihydrogen phosphate monohydrate, 30 mM sodium deoxycholate, and 30% ACN v/v at pH 8.3. The optimal UHPLC conditions used a mobile phase composed of 0.05% phosphate buffer and ACN with gradient elution. The gradient profile increased linearly from 10 to 21% ACN within the first 25 min, then increased to 33% ACN for the next 10 min. It took another 5 min to reach the 65% ACN, then for the next 5 min, it stayed unchanged. Sixteen samples of Rheum officinale and Rheum tanguticum collected from various locations were analyzed by CE and UHPLC methods. The metabolite profiles of CE were aligned and baseline corrected before chemometric analysis. Metabolomic signatures of rhubarb species from CE and UHPLC were clustered using principle component analysis and distance-based redundancy analysis; the clusters were not only able to discriminate different species but also different cultivation regions. Similarity measurements were performed by calculating the correlation coefficient of each sample with the authentic samples. Hybrid rhizome was clearly identified through similarity measurement of UHPLC metabolite profile and later confirmed by gene sequencing. The present study demonstrated that CE and UHPLC are efficient and effective tools to identify and authenticate herbs even coupled with simple detectors.

Ultra-high performance liquid chromatography coupled with photo-diode array and quadrupole/time-of-flight mass spectrometry based chemical profiling approach to evaluate the influence of preparation methods on the holistic quality of Qiong-Yu-Gao, a traditional complex herbal medicine

Qiong-Yu-Gao (QYG), consisting of Rehmanniae Radix (RR), Poriae (PO) and Ginseng Radix (GR), is a commonly used tonic traditional complex herbal medicine (CHM). So far, three different methods have been documented for preparation of QYG, i.e. method 1 (M1): mixing powders of GR and PO with decoction of RR; method 2 (M2): combining the decoction of RR and PO with the decoction of GR; method 3 (M3): decocting the mixture of RR, GR and PO. In present study, an ultra-high performance liquid chromatography coupled with photo-diode array and quadrupole/time-of-flight mass spectrometry (UHPLC-PDA-QTOF-MS/MS) based chemical profiling approach was developed to investigate the influence of the three preparation methods on the holistic quality of QYG. All detected peaks were unambiguously identified by comparing UV spectra, accurate mass data/characteristic mass fragments and retention times with those of reference compounds, and/or tentatively assigned by matching empirical molecular formula with that of known compounds, and/or elucidating quasi-molecular ions and fragment ions referring to information available in literature. A total of 103 components, mainly belonging to ginsenosides, phenethylalcohol glycosides, iridoid glycosides and triterpenoid acids, were identified, of which 5 degraded ginsenosides were putatively determined to be newly generated during preparation procedures of QYG samples. Triterpenoid acids and malonyl-ginsenosides were detected only in M1 samples, while degraded ginsenosides were merely detectable in M2/M3 samples. The possible reasons for the difference among chemical profiles of QYG samples prepared with three methods were also discussed. It could be concluded that preparation method do significantly affect the holistic quality of QYG. The influence of the altered chemical profiles on the bioactivity of QYG needs further investigation. The present study demonstrated that UHPLC-PDA-QTOF-MS/MS based chemical profiling approach is efficient and reliable for evaluating the holistic quality of traditional CHM.

HPLC-DAD method for comprehensive quality control of Semen Strychni

CONTEXT

Semen Strychni is the seed of Strychnos nux-vomica L. (Loganiaceae). Its quality control procedure remains an issue since previous reports only focused on Strychnos alkaloids. To the best of our knowledge, chlorogenic acid (a phenolic acid) and loganin (an iridoid glycoside) are selected for the first time as marker constituents of quality control for Semen Strychni because of their bioactive activity correlating with therapeutic effects.

OBJECTIVE

This study aimed to develop a simple and comprehensive quantity control method for Semen Strychni.

MATERIALS AND METHODS

The optimal ultrasonic extraction procedure was carried out for 45 min using 50% aqueous methanol with 1% formic acid. The satisfactory chromatographic separation was achieved on an Ultimate LP-C18 column with gradient elution using acetonitrile and water containing 30 mmol/L ammonium acetate and 1% formic acid. The high performance liquid chromatography method with diode array detector was validated for linearity, limit of detection and quantification (LOQ), precision, repeatability, accuracy and stability.

RESULTS

All the calibration curves showed good linearity (r(2) ≥ 0.999). The LOQ values for chlorogenic acid, loganin, strychnine, brucine, strychnine N-oxide and brucine N-oxide were 0.54, 0.83, 0.48, 0.50, 0.52 and 0.54 μg/mL, respectively. The method was reproducible with good accuracy in the range 95.6-104.4% and relative standard deviation (RSD) values less than 4.55%. The method was then applied to determine the components of the seed coat, seed leaf, endosperm and whole seed of Semen Strychni.

CONCLUSION

This newly established method is validated as a simple and practical tool for authentication and quality control of Semen Strychni.

Application of a rapid and efficient quantitative analysis method for traditional Chinese medicines: the case study of quality assessment of Salvia miltiorrhiza Bunge

A reference extractive, containing multiple active known compounds, has been considered to be an alternative to individual reference standards. However, in the Chinese Pharmacopoeia (ChP) the great majority of reference extractives have been primarily used for qualitative identification by thin-layer chromatography (TLC) and few studies on the applicability of reference extractives for quantitative analysis have been presented. Using Salvia miltiorrhiza Bunge as an example in this paper, we first present a preliminary discussion on the feasibility and applicability of reference extractives for the quantitative analysis of TCMs. The reference extractive of S. miltiorrhiza Bunge, comprised of three pharmacological marker compounds, namely cryptotanshinone, tanshinone I and tanshinone IIA, was prepared from purchased Salvia miltiorrhiza Bunge by extraction with acetone under reflux, followed by silica gel column chromatography with stepwise elution with petroleum ether-ethyl acetate (25:1, v/v, 4.5 BV) to remove the non-target components and chloroform-methanol (10:1, v/v; 3 BV) to yield a crude reference extractive solution. After concentration, the solution was further purified by preparative reversed-phase HPLC on a C18 column with isocratic elution with 77% methanol aqueous solution to yield the total reference extractive of S. miltiorrhiza Bunge. Thereafter, the reference extractive was applied to the quality assessment of S. miltiorrhiza Bunge using high-performance liquid chromatography (HPLC) coupled with diode array detection (DAD). The validation of the method, including linearity, sensitivity, repeatability, stability and recovery testing, indicated that this method was valid, reliable and sensitive, with good reproducibility. The developed method was successfully applied to quantify seven batches of samples collected from different regions in China and the results were also similar to those obtained using reference standards, with relative standard deviation (RSD) <3%. Preparation of a reference extractive of S. miltiorrhiza Bunge was significantly less expensive and time consuming than preparation of a corresponding reference standard. Quantitative analysis using a reference extractive was shown to be simple, low-cost, time-saving and practical, with high sensitivity and good stability; and is, therefore, a strong alternative to the use of reference standards.

Batch-to-batch quality consistency evaluation of botanical drug products using multivariate statistical analysis of the chromatographic fingerprint

Botanical drug products have batch-to-batch quality variability due to botanical raw materials and the current manufacturing process. The rational evaluation and control of product quality consistency are essential to ensure the efficacy and safety. Chromatographic fingerprinting is an important and widely used tool to characterize the chemical composition of botanical drug products. Multivariate statistical analysis has showed its efficacy and applicability in the quality evaluation of many kinds of industrial products. In this paper, the combined use of multivariate statistical analysis and chromatographic fingerprinting is presented here to evaluate batch-to-batch quality consistency of botanical drug products. A typical botanical drug product in China, Shenmai injection, was selected as the example to demonstrate the feasibility of this approach. The high-performance liquid chromatographic fingerprint data of historical batches were collected from a traditional Chinese medicine manufacturing factory. Characteristic peaks were weighted by their variability among production batches. A principal component analysis model was established after outliers were modified or removed. Multivariate (Hotelling T(2) and DModX) control charts were finally successfully applied to evaluate the quality consistency. The results suggest useful applications for a combination of multivariate statistical analysis with chromatographic fingerprinting in batch-to-batch quality consistency evaluation for the manufacture of botanical drug products.

Recent methodology in ginseng analysis

As much as the popularity of ginseng in herbal prescriptions or remedies, ginseng has become the focus of research in many scientific fields. Analytical methodologies for ginseng, referred to as ginseng analysis hereafter, have been developed for bioactive component discovery, phytochemical profiling, quality control, and pharmacokinetic studies. This review summarizes the most recent advances in ginseng analysis in the past half-decade including emerging techniques and analytical trends. Ginseng analysis includes all of the leading analytical tools and serves as a representative model for the analytical research of herbal medicines.

Utilization of gene expression signature for quality control of traditional Chinese medicine formula Si-Wu-Tang

The current study utilized a combined pharmacokinetic and genomic approach to demonstrate the feasibility of a new quality control method by using a panel of special differentially expressed genes (DEGs) as unique fingerprint to serve as marker of in vivo bioactivity for a representative traditional Chinese medicine (TCM) formula, Si-Wu-Tang (SWT). The method involves firstly obtaining possible in vivo active components, i.e., the "absorbable" components from the permeate of the Caco-2 monolayer model to simulate oral administration of two specific SWT products (CU-SWT, J-SWT), their component single herbs (Angelicae, Chuanxiong, Paeoniae, and Rehmanniae), and a standard mixture of active compounds (ferulic acid, ligustilide, senkyunolide A). Then, these respective absorbable components were incubated with MCF-7 cells to determine the gene expression profile using microarray processing/analysis as well as real-time PCR. From the available DEGs identified following the incubation, the magnitude of change in DEGs by real-time PCR was found to be consistent with that by microarray. The designated DEGs from the CU-SWT permeate were found to be distinct from other 19 products. Furthermore, the changes in the DEGs resulting from MCF-7 cells treated by eight replicate extracts of CU-SWT on three separate days were consistent. These results demonstrated sufficient specificity and consistency of the DEG panel which could serve as a unique bioactive "fingerprint" for the designated SWT product. The present method for DEG determination may be applied to other TCM products and with further definitive study can potentially provide a unique method for quality control of TCM in the future.

Multidimensional information-based HPLC technologies to evaluate traditional chinese medicine

Traditional Chinese medicines (TCMs) are usually complex mixtures and contain hundreds of chemically different constituents, which make the quality control (QC) of crude drugs and their medical preparations extremely difficult. In the past years, with the rapid development of modern instrumental analysis and computer-aided data processing techniques, great progress has been made in the research of quality standards and the development of QC techniques. Among them, the use of the high-performance liquid chromatography (HPLC) technique is one of the best approaches because of its high separation efficiency. However, one-way separation, single detection methods or data processing cannot meet the needs of the QC of TCMs. Multidimensional information-based HPLC technologies such as two-dimensional HPLC, HPLC coupled with several different detection methods and HPLC fingerprint combined with multicomponent quantification have solved this problem with their comprehensive analysis; these methods have gradually been accepted by more researchers for further in-depth study. The present work provides an overview of the development of QC for TCMs based on HPLC technologies with modern hyphenated techniques, multiseparation methods and some common data processing methods in fingerprint spectra over the last six years.

A dynamic multiple reaction monitoring method for the multiple components quantification of complex traditional Chinese medicine preparations: Niuhuang Shangqing pill as an example

It is a challenging task to simultaneously and quantitatively analyze multiple components in DFF [Da-Fu-Fang, namely, complex traditional Chinese medicine (TCM) preparations containing more than ten TCMs] due to their numerous and extreme complex chemical compositions possessing a wide variety of chemical and physical features, and their very low content. Rather than using a conventional mass spectrometry (MS) method with multiple reaction monitoring (MRM), in the current study, this challenge was addressed by using dynamic multiple reaction monitoring (DMRM). Using a DFF, Niuhuang Shangqing pill, which is composed of 19 TCMs, as a model, a rapid (one run in 20min), sensitive [lower limit of detection (LOD) and limit of quantitation (LOQ) were achieved comparable with MRM] and accessible (a standard HPLC/MS/MS instrumentation was employed) MS method was successfully developed for the simultaneous quantification of 41 bioactive components which represented 15 of the 19 medicinal plants. A comparison of LOD and LOQ using MRM and DMRM was made to quantitatively reveal that the latter demonstrated advantages over the former. Meanwhile, a standard operating procedure concerning the development of a new DMRM method was recommended. The MS data were obtained in the positive ion mode with electrospray ionization as the ion source, acetonitrile and water as mobile phase and a Kinetex C18 core-shell column (100mm×2.10mm, 2.6μm, Phenomenex Inc.) as the analytical column. This method was then applied to 32 batches of samples. It transpired, through principal component analysis and orthogonal partial least squares discriminant analysis, that the consistency of the products was relatively good within one company, but poor among different companies among the 32 samples; one failed to qualify in terms of the Chinese Pharmacopeia. This work illustrated that the proposed DMRM method was particularly suitable for quantifying the trace components in DFF and capable of ensuring the quality of DFF.

Sensitive and reliable multianalyte quantitation of herbal medicine in rat plasma using dynamic triggered multiple reaction monitoring

There is a growing need both clinically and experimentally to improve the determination of the blood levels of multiple chemical constituents in herbal medicines. The conventional multiple reaction monitoring (cMRM), however, is not well suited for multi-component determination and could not provide qualitative information for identity confirmation. Here we apply a dynamic triggered MRM (DtMRM) algorithm for the quantification of 20 constituents in an herbal prescription Bu-Zhong-Yi-Qi-Tang (BZYQT) in rat plasma. Dynamic MRM (DMRM) dramatically reduced the number of concurrent MRM transitions that are monitored during each MS scan. This advantage has been enhanced with the addition of triggered MRM (tMRM) for simultaneous confirmation, which maximizes the dwell time in the primary MRM quantitation phase, and also acquires sufficient MRM data to create a composite product ion spectrum. By allowing optimized collision energy for each product ion and maximizing dwell times, tMRM is significantly more sensitive and reliable than conventional product ion scanning. The DtMRM approach provides much higher sensitivity and reproducibility than cMRM.

The degradation mechanism of toxic atractyloside in herbal medicines by decoction

Atractyloside (ATR) is found in many Asteraceae plants that are commonly used as medicinal herbs in China and other eastern Asian countries. ATR binds specifically to the adenine nucleotide translocator in the inner mitochondrial membrane and competitively inhibits ADP and ATP transport. The toxicity of ATR in medical herbs can be reduced by hydrothermal processing, but the mechanisms of ATR degradation are not well understood. In this study, GC-MS coupled with SPE and TMS derivatisation was used to detect ATR levels in traditional Chinese medicinal herbs. Our results suggest that ATR molecules were disrupted by decomposition, hydrolysis and saponification after heating with water (decoction) for a long period of time. Hydrothermal processing could decompose the endogenous toxic compounds and also facilitate the detoxification of raw materials used in the Chinese medicine industry.

A study on the use of near-infrared spectroscopy for the rapid quantification of major compounds in Tanreqing injection

In this paper we describe the strategy used in the development and validation of a near infrared spectroscopy method for the rapid determination of baicalin, chlorogenic acid, ursodeoxycholic acid (UDCA), chenodeoxycholic acid (CDCA), and the total solid contents (TSCs) in the Tanreqing injection. To increase the representativeness of calibration sample set, a concentrating-diluting method was adopted to artificially prepare samples. Partial least square regression (PLSR) was used to establish calibration models, with which the five quality indicators can be determined with satisfied accuracy and repeatability. In addition, the slope/bias (S/B) method was used for the models transfer between two different types of NIR instruments from the same manufacturer, which is contributing to enlarge the application range of the established models. With the presented method, a great deal of time, effort and money can be saved when large amounts of Tanreqing injection samples need to be analyzed in a relatively short period of time, which is of great significance to the traditional Chinese medicine (TCM) industries.

UPLC-PDA-ESI-MS/MS analysis of compounds extracted by cardiac h9c2 cell from Polygonum orientale

INTRODUCTION

A flavonoid-enriched extract (FEE) of Polygonum orientale was reported to show cardioprotective effect but only very few compounds were reported to contribute to the effect. Identification of compounds interacting with the target cardiac cell is important for the understanding of active compounds.

OBJECTIVE

To develop an efficient method for the screening of potential active compounds directly acting on the target cardiac cell in FEE and to structurally characterise these compounds.

METHODOLOGY

Flavonoid-enriched extract was prepared by extraction of the plant with water, addition of ethanol to the solution to remove polysaccharides and proteins, and removal of tannins by a polyamide column chromatography. Cell extraction was conducted on a cardiac h9c2 cell and the solution containing compounds released from the cell were desalted by solid phase extraction. Compounds present in the cell extract were detected by ultra-performance liquid chromatography (UPLC) and targeted multi-reaction monitoring (MRM), while their structures were characterised by UPLC-photodiodide array (PDA)-electrospray ion source (ESI)-MS/MS investigations of the FEE.

RESULTS

Twenty-three potentially active phenolics including ten flavonoid C-glycosides and six flavonoid O-glycosides have been identified from the 40 compounds screened in the cell extract. Among these compounds, three were new and nine were identified from this plant for the first time. Strategies for the structural characterisation of flavonoid glycosides were also discussed.

CONCLUSION

The study has shown that FEE contains the flavonoid as its major principles and the coupling of UPLC-PDA-ESI-MS/MS and targeted UPLC-MRM with target cell extraction is an efficient method for the screening and structural characterisation of potential active compounds.

Discrimination of different genuine Danshen and their extracts by Fourier transform infrared spectroscopy combined with two-dimensional correlation infrared spectroscopy

In this study, six varieties of Danshen from different populations and genuine ("Daodi" in Chinese transliteration) regions were discriminated and identified by a three-step infrared spectroscopy method (Fourier transform-infrared spectroscopy (FT-IR) coupled with second derivative infrared spectroscopy (SD-IR) and two dimensional correlation infrared spectroscopy (2D-IR)). Though only small differences were found among the FT-IR spectra of the six Danshen samples, the positions and intensities of peaks at 3393, 3371, 1613, 1050, and 1,036 cm(-1) could be considered as the key factors to discriminate them. More significant differences were exhibited in their SD-IR, particularly for the peaks around 1080, 1144, 695, 665, 800, 1610, 1510, 1450, 1117 and 1,077 cm(-1). The visual 2D-IR spectra provided dynamic chemical structure information of the six Danshen samples with presenting different particular auto-peak clusters, respectively. Moreover, the contents of salvianolic acid B in all samples were measured quantitatively by a validated ultra performance liquid chromatography (UPLC), which was consistent with the FT-IR findings. This study provides a promising method for characteristics and quality control of the complicated and extremely similar herbal medicine like Danshen, which is more cost effective and time saving.

Rapid differentiation of Panax ginseng and Panax quinquefolius by matrix-assisted laser desorption/ionization mass spectrometry

A matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS)-based method has been developed for rapid differentiation between Panax ginseng and Panax quinquefolius, two herbal medicines with similar chemical and physical properties but different therapeutic effects. This method required only a small quantity of samples, and the herbal medicines were analyzed by MALDI-MS either after a brief extraction step, or directly on the powder form or small pieces of raw samples. The acquired MALDI-MS spectra showed different patterns of ginsenosides and small chemical molecules between P. ginseng and P. quinquefolius, thus allowing unambiguous differentiation between the two Panax species based on the specific ions, intensity ratios of characteristic ions or principal component analysis. The approach could also be used to differentiate red ginseng or P. quinquefolius adulterated with P. ginseng from pure P. ginseng and pure Panax quinquefolium. The intensity ratios of characteristic ions in the MALDI-MS spectra showed high reproducibility and enabled quantitative determination of ginsenosides in the herbal samples and percentage of P. quinquefolius in the adulterated binary mixture. The method is simple, rapid, robust, and can be extended for analysis of other herbal medicines.

Screening and analysis of the multiple absorbed bioactive components and metabolites of Baihe Zhimu Tang by the metabolic fingerprinting technique and liquid chromatography/diode array detection-electrospray ionization-mass spectrometry

BACKGROUND

Baihe Zhimu Tang (BZT) is a widely used traditional Chinese medicinal formula in treating various diseases; however, its active components have remained unknown.

MATERIALS AND METHODS

Based on the metabolic fingerprinting technique and liquid chromatography/diode array detection-electrospray ionization-mass spectrometry (LC/DAD-ESI-MS), a method for rapid screening and analysis of the multiple absorbed bioactive components and metabolites of an oral solution of Baihe Zhimu Tang (BZT) in rabbit plasma, urine and feces after oral administration of BZT was developed.

RESULTS

The results obtained from a comprehensive comparative analysis of the fingerprints of the BZT and its metabolic fingerprints in rabbit biological samples indicated that 19 components in the BZT were absorbed into the rabbit's body. Both of them were tentatively identified from their MS and UV spectra and retention behaviors by comparing the results with the reported literature. In addition, only six components were found in the metabolic fingerprints, which suggested that they might be metabolites of some components in the BZT.

CONCLUSION

The findings demonstrated that the proposed method could be used to rapidly and simultaneously analyze and screen the multiple absorbed bioactive constituents and metabolites in a formula of traditional Chinese medicines (TCMs) by comparing and contrasting the chromatographic fingerprints with its metabolic fingerprints. This is very important not only for the pharmaceutical discovery process and the quality control of crude drugs, but also for explaining the curative mechanism of TCMs.

Five-year follow-up study of a kidney-tonifying herbal Fufang for prevention of postmenopausal osteoporosis and fragility fractures

To observe the kidney-tonifying herbal Fufangs with phytoestrogenic epimedium for prevention of postmenopausal osteoporosis with both bone mineral density (BMD) and fracture as study endpoints, a 5-year multicenter follow-up study in 194 postmenopausal women (47-70 years old) was conducted in which the subjects were given oral administration of herbal Fufang (10 g/day, twice per day, n = 101) or placebo (n = 93). Both groups were supplemented daily with calcium (600 mg) and vitamin D (400 IU). BMD at distal radius, potential adverse events, and fracture incidence were evaluated at baseline and at 6, 12, 24, 36, 48, and 60 months. At the end of 5 years, 155 subjects had completed the study, with better adherence in the treatment group (13% dropouts, n = 88 at year 5) as compared with the control group (28% dropouts, n = 67 at year 5) (P < 0.05). No notable adverse events were observed in either group. In the treatment group BMD increased significantly from baseline (0.211 ± 0.022 g/cm(2)) to the end of the study (0.284 ± 0.015 g/cm(2)), whereas the control group decreased significantly from baseline (0.212 ± 0.023 g/cm(2)) to 5 years later (0.187 ± 0.022 g/cm(2)) (P < 0.05). The fracture incidence was 2.4 fold lower in the treatment group than in the control group, with a relative risk of 0.57 for the treatment group (95% CI, 0.43-0.70, P < 0.05). In conclusion, in addition to the beneficial effects of oral herbal Fufang on prevention of postmenopausal bone loss, this 5-year multi-center clinical study demonstrated for the first time its potential for reduction in fragility fracture incidence.

Chemical composition of Galla chinensis extract and the effect of its main component(s) on the prevention of enamel demineralization in vitro

To determine the chemical composition of Galla chinensis extract (GCE) by several analysis techniques and to compare the efficacy of GCE and its main component(s) in inhibition of enamel demineralization, for the development of future anticaries agents, main organic composition of GCE was qualitatively determined by liquid chromatography–time of flight–mass spectrometry (LC–TOF–MS) and quantified by high-performance liquid chromatography–diode array detector (HPLC–DAD). Inorganic ions were tested by inductively coupled plasma–atomic emission spectroscopy and F was especially measured by ion chromatography. Then, bovine enamel blocks were randomly divided into four treatment groups and were subjected to a pH-cycling regime for 12 times. Each cycle included 5-min applications with one of four treatments: 4 g⋅L⁻¹ GCE solution, 4 g⋅L⁻¹ gallic acid (GA) solution, 1 g⋅L⁻¹ NaF solution (positive control), deionized water (DDW, negative control), and then 60-min application in pH 5.0 acidic buffer and 5-min application in neutral buffer. Acidic buffers were retained for calcium analysis. The main organic composition of GCE were GA and its isomer, and, to a lesser extent, small molecule gallotannins. The content of GA in GCE was 71.3%±0.2% (w/w). Inorganic ions were present in various amounts, of which Ca was (136±2.82) µg⋅g⁻¹, and Zn was (6.8±0.1) µg⋅g⁻¹. No F was detected in GCE. In pH cycling, GA showed an effect similar to GCE in inhibiting enamel demineralization (P>0.05). GA was found to be the main effective, demineralization inhibiting component of GCE and could be a promising agent for the development of anticaries agents.

Quality assessment of commercial Magnoliae officinalis Cortex by ¹H-NMR-based metabolomics and HPLC methods

INTRODUCTION

The quality control of Magnoliae officinalis Cortex, a commonly used traditional Chinese medicine, is currently based on the assay of the two active compounds, honokiol and magnolol, by TLC or HPLC.

OBJECTIVE

To compare ¹H-NMR-based metabolomics with the HPLC method for controlling the quality of Magnoliae officinalis Cortex. To identify the metabolites contributing to the differences between the samples and to discriminate different medicinal parts and geographic origins of these samples by ¹H-NMR-based metabolomics.

METHODOLOGY

¹H-NMR and several multivariate analysis techniques were applied to analyse the extracts of 18 batches of Magnoliae officinalis Cortex commercial samples, and the contents of honokiol and magnolol in these samples were determined by HPLC. The correlation analysis between the data from ¹H-NMR and HPLC was performed with the mixOmics software based on an unsupervised method.

RESULTS

Honokiol and magnolol were the main compounds responsible for the discrimination of samples from different batches, thus proving that the choice of these two compounds as markers for quality assessment by HPLC is relevant. The two sources of Magnoliae officinalis Cortex recorded in the Chinese Pharmacopoeia, Magnolia officinalis and Magnolia officinalis var. biloba, could be differentiated from ¹H-NMR data, but the pattern recognition analysis by PLS-DA was unsuccessful in discriminating samples from various geographical origins.

CONCLUSION

The combination of ¹H-NMR that gives a comprehensive profile of the metabolites and HPLC that targets two biomarkers is an efficient means for a better quality control of Magnoliae officinalis Cortex.

Chromatographic fingerprinting and quantitative analysis for the quality evaluation of Xinkeshu tablet

A simple, sensitive and accurate method based on high performance liquid chromatography (HPLC) with diode array detector (DAD) was developed and validated for systematic quality evaluation of one type of traditional Chinese medicine preparations named Xinkeshu (XKS) tablet. In this study, the chromatographic fingerprints of XKS tablet were developed first, 23 peaks were selected as the common peaks to evaluate the similarities among different batches of XKS samples, which were manufactured in a long time span of three years. Additionally, simultaneous quantification of six markers in XKS tablet, including Danshensu, Protocatechuic aldehyde, Puerarin, Daidzin, Salvianolic acid B and Daidzein, was performed. The validation results showed that the developed method was specific, accurate, precise and robust. The preliminary explanation on why a close similarity between fingerprints did not exactly mean similar contents of chemical components in samples was given. The contribution of each chromatographic peak to similarity was also evaluated. The developed method offers an efficient, reliable and practical approach for systematic quality evaluation of XKS tablet.

Quantitative 1H NMR. Development and potential of an analytical method: an update

Covering the literature from mid-2004 until the end of 2011, this review continues a previous literature overview on quantitative (1)H NMR (qHNMR) methodology and its applications in the analysis of natural products. Among the foremost advantages of qHNMR is its accurate function with external calibration, the lack of any requirement for identical reference materials, a high precision and accuracy when properly validated, and an ability to quantitate multiple analytes simultaneously. As a result of the inclusion of over 170 new references, this updated review summarizes a wealth of detailed experiential evidence and newly developed methodology that supports qHNMR as a valuable and unbiased analytical tool for natural product and other areas of research.

Natural products and traditional medicine: turning on a paradigm

Paradigm shifts in the strategies and the sciences that would enhance the quality, safety, and efficacy of traditional medicines and dietary supplements in global health care are discussed. Some of the challenges facing traditional medicine in health care are described, and the importance of defining clear goals and directions for the information systems, botany, chemistry, and biology related to plants and health care, including for drug discovery and quality control, is indicated.

Bioactivity-based liquid chromatography-coupled electrospray ionization tandem ion trap/time of flight mass spectrometry for β₂AR agonist identification in alkaloidal extract of Alstonia scholaris

Although chromatographic fingerprinting combined with chemometrics, is a rational method for the quality control of traditional Chinese medicine (TCM), chemometrics cannot fully explore the relationship between chemical information and the efficacy of the potential activity. In the present work, a cell-based β₂ adrenergic receptor (β₂AR) agonist functional evaluation model coupled with high-performance liquid chromatography was developed to screen the potential β₂AR agonist components in the alkaloidal extract of Alstonia scholaris leaves. Using a liquid chromatography with ion trap time-of-flight mass spectrometry (LCMS-IT-TOF) system, the potential bioactive compounds in the prescription were identified and deduced based on the mass spectrometric fragmentation patterns, tandem mass spectrometry (MS/MS) data, and relevant literature. Several new β₂AR agonists of indole alkaloids were successfully found, and their activities were confirmed through an in vivo relaxant test on guinea pig tracheal muscles. The developed method is rapid and reliable compared with conventional fingerprinting and showed high sensitivity and resolution for the identification of β₂AR agonists in TCM prescriptions. This strategy clearly demonstrates that bioactivity-integrated fingerprinting is a powerful tool not only in screening and identifying potential lead compounds and in determining the therapeutic material basis of Chinese herbal prescriptions, but also in supplying suitable chemical markers for their quality control.