Static headspace‐multicapillary column with gas chromatography coupled to ion mobility spectrometry as a simple approach for the discrimination of crude and processed traditional Chinese medicines

The processing procedure can alter the nature and chemical transformation of traditional Chinese medicine to accommodate different clinical dispensing and preparation requirements. In this study, static headspace‐multicapillary column with gas chromatography coupled to ion mobility spectrometry was developed for the rapid and sensitive discrimination of crude and processed traditional Chinese medicine. Using Radix Paeoniae Alba as a traditional Chinese medicine model, the combined power of this approach was illustrated by classifying the crude and processed Radix Paeoniae Alba samples into two main categories. The contents of the main components in Radix Paeoniae Alba varied significantly. The established method could promote the use of ion mobility spectrometry in intrinsic quality control and differentiation of herbal medicines from other processed products or preparations.     

Simultaneous Determination of Paeoniflorin, Albiflorin and Benzoylpaeoniflorin in Radix Paeoniae Alba by TLC

Paeoniflorin, albiflorin and benzoylpaeoniflorin are three representative monoterpene glycosides in Radix Paeoniae Alba, a well-known traditional Chinese medicine with a great important biological activity. In the present paper, the three marker compounds were simultaneously quantified by TLC densitometric methods using high performance thin layer chromatography. The established method was validated in terms of LOD/LOQ, linearity, recovery and repeatability. The method was found to be precise with RSDs for intra-day in the range of 0.78–1.05, 0.67–0.98, 0.93–1.42% and for inter-day in the range of 0.85–1.23, 0.98–1.29, 1.28–1.94% for different concentrations of albiflorin, paeoniflorin and benzoylpaeoniflorin. Instrumental precision was 0.36, 0.41 and 0.45 (% RSD) for albiflorin, paeoniflorin and benzoylpaeoniflorin. Recoveries of abliflorinl, paeoniflorin and benzoylpaeoniflor were 98, 101.95 and 96.25%, respectively. The proposed method is simple, precise, specific, sensitive, and accurate and can be used for routine quality control of the crude drug.     

Detection of sulfur-fumigated paeoniae alba radix in complex preparations by high performance liquid chromatography tandem mass spectrometry

Detection of sulfur-fumigated Paeoniae Alba Radix (PAR) in different complex preparations is challenging due to the relatively lower content of PAR and interference from more complicated components in complex preparations with different multiple constituent herbs. In this study, a high performance liquid chromatography- triple-quadrupole tandem mass spectrometry method was developed for detecting sulfur-fumigated PAR in different complex preparations. Paeoniflorin, the major component of PAR, and paeoniflorin sulfonate, the characteristic artifact transformed from paeoniflorin during sulfur-fumigation of PAR, were used as chemical markers. Multiple reaction monitoring (MRM) scan was employed to maximize sensitivity and selectivity. Through optimizing full mass scan and daughter ion scan conditions, two mass transitions were selected and employed respectively for unequivocal identification of paeoniflorin and paeoniflorin sulfonate. The detection limits for paeoniflorin and paeoniflorin sulfonate using MRM were much lower than those detected with UV 270 nm. Paeoniflorin and paeoniflorin sulfonate could be simultaneously detected in different commercial PAR-containing complex preparations without interference of other components using the established method, indicating that the newly established method was selective and sensitive enough for screening sulfur-fumigated PAR in commercial complex preparations.     

Ultra-performance liquid chromatography coupled with high-resolution quadrupole time-of-flight mass spectrometry analysis of the impact of bran-processing on the chemical profile of Radix Paeoniae Alba (Baishao)

In this study, a rapid and versatile ultra-performance liquid chromatography coupled with high-resolution quadrupole time-of-flight mass spectrometry-based chemical profiling approach was applied to evaluate chemical constitution of crude and processed Radix Paeoniae Alba (RPA) samples. A total of 44 compounds were identified, among which the contents of 9 compounds in processed samples were obviously decreased and 8 compounds were increased. Furthermore, compound 28 was not found in RPA sample after stir-frying with wheat bran. The proposed method provided a chemical basis for exploring the processed mechanism of herbal medicine.     

Quantitative evaluation main of the components in Paeoniae Radix Alba–Atractylodis Macrocephalae Rhizoma herbal pair by high‐performance liquid chromatography

The aim of this study was to investigate the influence of compatibility on the contents of main compounds in Paeoniae Radix Alba and Atractylodis Macrocephalae Rhizoma. Ten compounds were separated on an Inertsil ODS‐SP Extend C₁₈ column (250 mm × 4.6 mm, 5 μm) and detected by a diode array detector with the mobile phase consisting of aqueous phosphoric acid (0.1%, v/v; A) and acetonitrile (B) by linear gradient elution. All analytes showed good linearity over a wide concentration range (r² ≥ 0.9989). The limits of detection and quantification were <8.10 and 10.80 μg/mL, respectively. The intra‐ and interday variations were <4.36%. The average recoveries were observed from 94.90 to 103.38%, with relative standard deviation ranging from 1.23 to 3.15% for the analytes. The established method was reliable enough for global quality evaluation of Paeoniae Radix Alba, Atractylodis Macrocephalae Rhizoma, and their co‐decoctions.     

Development of a simple HPLC method for determination of paeoniflorin-metabolizing activity of intestinal bacteria in rat feces

A simple and reproducible HPLC method for the determination of paeoniflorin (PF)-metabolizing activity of intestinal bacteria in rat feces was developed and validated. Orally administered PF, a major active constituent of Paeoniae Radix, is metabolized into a bioactive compound, paeonimetabolin I (PM-I) by intestinal bacteria. Direct determination of the PF-metabolizing rate into PM-I is hard to achieve by HPLC due to the lack of intense chromophore in PM-I. However, when PF was incubated with Lactobacillus brevis, an intestinal bacterium, in the presence of phenylmercaptan, the metabolizing rate of PF into 8-phenylthio-paeonimetabolin I (PT-PM-I) was found to be equivalent to that of PF into PM-I. Thus, the PF-metabolizing activity of intestinal bacteria in rat feces was determined by measuring the rate of biotransformation of PF into PT-PM-I, which was detected by HPLC at 255 nm. This method can be utilized in the biopharmaceutical study of traditional Chinese formulations containing Paeoniae Radix.     

Quality assessment of radix salviae miltiorrhizae

This paper describes an improved quality assessment method for Radix Salviae Miltiorrhizae (Root of Salvia miltiorrhiza BGE.) which was established using chromatographic fingerprinting and quantification of multiple marker compounds in the crude drug. High-performance thin-layer chromatography (HPTLC) fingerprinting of water-soluble phenolics and nonpolar tanshinones was performed separately and the authentication of Radix Salviae Miltiorrhizae was achieved by comparing the fingerprints of the samples with those of the reference crude drug and by comparing the Rf values of the bands in TLC fingerprints with those of reference compounds. HPLC fingerprints were obtained by simultaneous separation of phenolics and diterpenoids in Radix Salviae Miltiorrhizae. The HPLC fingerprints of seven batches of samples from different regions of China showed similar chromatographic patterns, and seven peaks were selected as characteristic peaks. The relative retention time of these characteristic peaks in the HPLC fingerprints was established as an important parameter for the identification of this herbal medicine. The pharmacologically active marker compounds salvianolic acid B, rosmarinic acid, and tanshinone IIA in herbal medicine were quantitatively determined using reverse-phase HPLC techniques. The HPLC quantitation methods of the three marker compounds were validated and the measurement uncertainty, which is important for setting the proposed content limit of the marker compounds in herbal medicine, were further evaluated.     

益气通痹胶囊质量标准研究

采用薄层色谱法对益气通痹胶囊中黄芪、何首乌、五味子、赤芍、延胡索进行定性鉴别,采用高效液相色谱法测定了制剂中淫羊藿苷的含量. 所用薄层色谱具有鉴别特征,色谱斑点清晰,专属性强. 淫羊藿苷在0.55~3.30 μg范围内呈良好的线性关系(r =0.99996),平均回收率为98.4%,RSD为0.62 %. 所建立的定性和定量方法,操作简便可靠,专属性强,重现性好,能较全面反映该制剂内在质量,可作为益气通痹胶囊新药研发质量控制标准.     

Kinetic distribution of paeoniflorin in cortex of normal and cerebral ischemia-reperfusion rats after intravenous administration of Paeoniae Radix extract

The time course of paeoniflorin in the cortex of normal and cerebral ischemia-reperfusion rats, following intravenous administration of Paeoniae Radix extract at a dose of 60 mg/kg of paeoniflorin, was determined using high-performance liquid chromatographic (HPLC) assay. The results showed that paeoniflorin could penetrate through the blood-brain barrier to reach the cortex, and that the injuries of ischemia-reperfusion could play an important role in pharmacokinetic process of paeoniflorin in the cortex after intravenous administration of Paeoniae Radix extract. The cortex concentrations of paeoniflorin in cerebral ischemia-reperfusion rats were lower 5 min after dosing and declined more slowly than that in normal control.     

Rapid determination of Paeoniae Radix using near infrared spectroscopy

A rapid and nondestructive near infrared spectroscopy (NIRS) was used to differentiate different geographical Paeoniae Radix and quantitatively predict the content of main active components. Paeoniflorin, albiflorin and benzoylalbiflorin were analyzed simultaneously with an Agilent Zorbax SB-C₁₈ column by gradient elution under high-performance liquid chromatography-UV detection (HPLC-UV). Multiplicative scatter correction (MSC), first derivative and Savitsky-Golay were utilized together to correct the scattering effect and eliminate the baseline shift in all near infrared diffuse reflectance spectra in order to give a better correlation with the results obtained by HPLC-UV. Multiplicative regression methods were discussed. The spectra calibration equations produced highest correlation coefficient values (R²) and lowest root mean square error of prediction (RMSEP) were used for the determination of paeoniflorin, albiflorin and benzoylalbiflorin. The RMSEP of paeoniflorin, albiflorin and benzoylabiflorin were 0.866 mg/g, 0.369 mg/g and 0.084 mg/g, respectively, and the R² of cross validation were 0.986, 0.939 and 0.971, respectively. Furthermore with the use of principle component analysis (PCA), Paeoniae Radix was clustered according to different cultivation area. The results indicated that the NIRS method could be used for the quality control of Chinese herbal medicine.     

Species differentiation and quality assessment of Radix Paeoniae Rubra (Chi-shao) by means of high-performance liquid chromatographic fingerprint

There are two species under the monograph of Radix Paeoniae Rubrae ("Chi-shao" in Chinese) in Chinese Pharmacopoeia 2005 edition-Paeonia lactiflora Pallas and Paeonia veitchii Lynch. Due to different species and growing conditions, there are significant chemical differences between the two species, which may result in the improper clinical usage under the same name. Chemical pattern expressed by high performance liquid chromatographic (HPLC) fingerprint analysis can play an important role in species differentiation and quality control of Radix Paeoniae Rubra. In the present work, HPLC fingerprints of two kinds of Radix Paeoniae Rubra have been established and analysed with chemometric methods including similarity evaluation and principal component analysis. Both of the fingerprint common patterns of the two species comprise 13 characteristic peaks, nine of which were common peaks of the two species. However, significant differences between the roots of P. veitchii and P. lactiflora exist not only in the content of certain constituents, especially phenolic acids but also in peak-to-peak ratios expressed by the fingerprint patterns. According to the recent pharmacological studies on polyphenolic constituents, root originating from P. veitchii may possess better efficacy and quality than that from P. lactiflora. Our research reveals that further pharmacological investigation is very necessary to determine whether the two species should be embodied under the same monograph in Chinese Pharmacopoeia.     

Rapid determination of paeoniflorin and three sugars in Radix Paeoniae Alba by capillary electrophoresis.

A method based on capillary electrophoresis with electrochemical detection has been developed for the separation and determination of paeoniflorin, sucrose, glucose, and fructose in traditional Chinese medicine, Radix Paeoniae Alba. The effects of several important factors, such as the concentration of NaOH, the separation voltage, the injection time, and the detection potential, were investigated to determine the optimum conditions. The detection electrode was a 300-microm diameter copper disc electrode at a working potential of +0.60 V (versus SCE). The four analytes can be well separated within 8 min in a 40 cm length fused-silica capillary at a separation voltage of 12 kV in a 75 mM NaOH aqueous solution. The relation between the peak current and the analyte concentration was linear over about 3 orders of magnitude with detection limits (S/N = 3) ranging from 1 to 2 microM for all analytes. The proposed method has been successfully applied for the determination of the paeoniflorin and sugars in real plant samples with satisfactory assay results.     

Interaction of the main components from the traditional Chinese drug pair Chaihu-Shaoyao based on rat intestinal absorption

The Chaihu-Shaoyao drug pair (Bupleuri Radix and Paeoniae Radix Alba) which is a traditional Chinese drug pair, has been widely used for anti-inflammatory purposes. Saikosaponin a (SSA), saikosaponin d (SSD) and paeoniflorin are identified as the main components in the pair. The present study focused on the interaction of the main components based on investigating their intestinal absorption using a four-site perfused rat intestinal model in order to clarify the mechanism of the compatibility of Chaihu-Shaoyao. The concentrations of SSA, SSD and paeoniflorin in the intestinal perfusate were determined by LC/MS or UPLC (Ultra Performance Liquid Chromatography) methods, followed by P*(eff) (effective permeability) and 10% ABS (the percent absorption of 10 cm of intestine) calculations. The results showed that all of the three main components displayed very low permeabilities (P*(eff) < 0.4), which implied their poor absorption in the rat intestine. The absorption levels of SSA and SSD were similar in intestine and higher in ileum than those in other intestinal regions in the decreasing order: colon, jejunum and duodenum. However, there is no significant difference in the absorption of paeoniflorin in the four segments (P < 0.05). The P*(eff) values of paeoniflorin exhibited an almost 2.11-fold or 1.90-fold increase in ileum when it was co-administrated with SSA and SSD, as well as 2.42-, 2.18-fold increase in colon, respectively, whereas the absorptions of SSA and SSD were not influenced by paeoniflorin. In conclusion, SSA and SSD could promote the absorption of paeoniflorin. To some extent this might explain the nature of the compatibility mechanisms of composite formulae in TCMs.     

液质联用技术研究人参与干姜或赤芍配伍前后人参皂苷及其抗氧化活性的变化

采用高效液相色谱与电喷雾质谱联用技术(HPLC-ESI-MS),对不同质量比的人参与干姜或赤芍配伍过程中人参皂苷的变化进行了研究,发现随加入的干姜量增加,共煎液中的人参皂苷含量依次降低;少量的赤芍可以使各皂苷的溶出量增加;同时测定了人参单煎液、人参与干姜、赤芍共煎液中正丁醇提取物和水提物的抗氧化活性。 以抗坏血酸(500 μmol/L)作对照,人参与干姜、赤芍配伍溶液的抗氧化活性比人参单煎液要好,同时人参与干姜、赤芍共煎液中正丁醇提取物的FRAP(铁离子还原/抗氧化能力测定)值分别为1562.29和2969.78 μmol/L,高于人参与2种药单煎液（1260.27和2502.07 μmol/L）之和。     

Qualitative and quantitative determination of ten major saponins in Platycodi Radix by high performance liquid chromatography with evaporative light scattering detection and mass spectrometry

Saponins in Platycodi Radix (platycosides) exhibit potent biological activities in mammalian systems, including several beneficial effects such as anti-inflammatory, immunomodulatory and anti-obesity activities. In this study, we developed a new HPLC separation coupled with evaporative light scattering detector (ELSD) for the simultaneous quantitative determination of ten major saponins in Platycodi Radix. Simultaneous separation of these saponins was achieved on a C18 analytical column. The mobile phase consisted of a gradient of aqueous acetonitrile. The method was validated for linearity, precision, accuracy, limit of detection and quantification. Electrospray ionization mass spectrometry (ESI-MS) and liquid chromatography coupled with on-line mass spectrometry (LC-ESI MS/MS) were applied to identify platycosides in the purified fractions and in the crude extract. Under ESI-MS/MS conditions, the fragmentation patterns of [M-H]- ions exclusively show signals corresponding to cleavage of the glycosidic bonds, thus allowing a rapid identification of saponins in the crude extract of Platycodi Radix. The validated HPLC method provides a new basis of overall assessment on quality of Platycodi Radix, and ESI-MS/MS and LC-ESI MS/MS approaches offers analytical tools for a rapid screening of platycosides in the crude extract.     

Elution–extrusion counter‐current chromatography for the separation of two pairs of isomeric monoterpenes from Paeoniae Alba Radix

In this work, a simple and efficient protocol for the rapid separation of two pairs of isomeric monoterpenes from Paeoniae Alba Radix was developed by combining macroporous resin and elution–extrusion counter‐current chromatography. The crude extract was firstly subjected to a D101 macroporous resin column eluted with water and a series of different concentrations of ethanol. Then, effluents of 30 and 95% ethanol were collected as sample 1 and sample 2 for further counter‐current chromatography purification. Finally, a pair of isomers, 96 mg of compound 1 and 48 mg of compound 2 with purities of 91.1 and 96.2%, respectively, was isolated from 200 mg of sample 1. The other pair of isomers, 14 mg of compound 3 and 8 mg of compound 4 with purities of 93.6 and 88.9%, respectively, was isolated from 48 mg of sample 2. Their purities were analyzed by high‐performance liquid chromatography, and their chemical structures were identified by mass spectrometry and ¹H NMR spectroscopy. Compared to a normal counter‐current chromatography separation, the separation time and solvent consumption of elution–extrusion counter‐current chromatography were reduced while the resolutions were still good. The established protocol is promising for the separation of natural products with great disparity of content in herbal medicines.     

Detection of albiflorin and paeoniflorin in Paeoniae Radix by reversed-phase high-performance liquid chromatography with pulsed amperometric detection

We have developed a reversed-phase high-performance liquid chromatography-pulsed amperometric detection (RP-HPLC-PAD) method for the detection of albiflorin and paeoniflorin in Paeoniae Radix and Wu-ji-san. Albiflorin and paeoniflorin were completely separated using 10% acetonitrile in 5 mM sodium phosphate buffer (pH 3.0) as an eluent and detected by PAD under alkaline conditions after using a post-column delivery system. The limit of detection (S/N = 3) and the limit of quantification (S/N = 10) were 0.10 and 0.35 ng for albiflorin, and 0.20 and 0.50 ng for paeoniflorin, respectively. The coefficients of linear regression were 0.9995 and 0.9999 for concentrations between 0.035 and 100 μg/mL. The intra- and inter-day precision (RSDs) was less than 3.56% in Paeoniae Radix and Wu-ji-san. The average recoveries from Paeoniae Radix and Wu-ji-san were 99.01–100.94% and 99.46–100.64%. This method shows higher selectivity than HPLC–UV method for analyzing albiflorin and paeoniflorin in Chinese medicinal preparation.     

A comparative analysis of raw and processed Radix Paeoniae Alba samples using HPLC,chemometrics, and antioxidant activity

Radix Paeoniae Alba (RPA) and its processed products are commonly used in traditional Chinese medicine, but the chaos phenomenon among processed products often occurs. In this study, we used multiple chemometric methods to analyze raw and six different processed products of RPA based on HPLC fingerprinting. Heat map analysis was used to assess the changes in chemical composition. Principal component analysis was used for classification, and the samples were divided into four classes: class 1 (raw, wine-processed, and vinegar-processed products), class 2 (bran-processed and soil-processed products), class 3 (stir-fried products), and class 4 (coke products). Further, the orthogonal partial least squares discriminant analysis model was used to obtain chemical markers among different classes. The antioxidant property of RPA is an important factor responsible for its pharmacological effects, and so the antioxidant activity of RPA was also investigated. We measured 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and hydroxyl radical scavenging ability, and ferric reducing antioxidant power. The total antioxidant activity follows the order: coke > stir-fried > soil-processed > bran-processed > wine-processed > raw > vinegar-processed products. These results suggest that different processing methods affect the chemical composition and antioxidant power of RPA, and thus, different products of RPA should not be mixed.     

Quantitative analysis of different batches of raw,wine‐processed,and vinegar‐processed Paeoniae Alba Radix using ultra‐performance convergence chromatography coupled with photo diode array detection

Supercritical fluid chromatography is a safe and ecofriendly analytical technique that has not been fully applied to the analysis of traditional Chinese medicine. This is the first study on the separation of six quality markers—paeoniflorin, albiflorin, benzoyl paeoniflorin, oxypaeoniflorin, gallic acid and benzoic acid—from raw, wine‐baked and vinegar‐baked Paeoniae Alba Radix (PAR) by Supercritical fluid chromatography. Optimum separation was achieved on an HSS C₁₈ SB column (100 × 3.0 mm, 1.8 μm particles) with a gradient elution of high‐purity carbon dioxide as mobile phase A and methanol–acetonitrile (70:30, v/v) with 0.10% phosphoric acid as mobile phase B. The flow rate was set at 0.7 mL/min for 15.0 min. The method was validated in terms of the overall intraday and interday precision, with relative standard deviations (RSDs) of 0.87–2.87 and 1.47–3.63%, respectively. The recoveries were 98.10–103.60% with an RSD of 1.00–3.40%. The stability of the RSD values was in the range 1.10–3.78%. The developed approach was successfully applied and provides a valuable reference for the quality assessment of PAR and processed PAR. The results also revealed that the standardization of processing technology is of great significance to the fluctuations in quality before and after the processing of traditional Chinese medicine.