Comparison of reversed‐phase liquid chromatography and hydrophilic interaction chromatography for the fingerprint analysis of Radix isatidis

Radix isatidis is a famous anti‐influenza virus herbal medicine traditionally taken as a water decoction. However, the chemical fingerprint analysis of Radix isatidis is dominantly based on RPLC, from which it is difficult to obtain fingerprint information of hydrophilic compounds. Here, we developed the separation of Radix isatidis by RPLC and hydrophilic interaction chromatography, comparing the traditional RPLC fingerprint with the hydrophilic interaction chromatography fingerprint. Besides, an anti‐viral assay of Radix isatidis was conducted to evaluate its efficacy. The fingerprint–efficacy relationships between the fingerprints and the anti‐viral activity were further investigated with principal component regression analysis. The results showed that the anti‐viral activity correlated better with the hydrophilic interaction chromatography fingerprint than with the RPLC fingerprint. This study indicates that hydrophilic interaction chromatography could not only be a complementary method to increase the fingerprint coverage of conventional RPLC fingerprint, but also can better represent the efficacy and quality of Radix isatidis.     

Chemical fingerprint of Ganmaoling granule by double‐wavelength ultra high performance liquid chromatography and ultra high performance liquid chromatography with quadrupole time‐of‐flight mass spectrometry

A method incorporating double‐wavelength ultra high performance liquid chromatography with quadrupole time‐of‐flight mass spectrometry was developed for the investigation of the chemical fingerprint of Ganmaoling granule. The chromatographic separations were performed on an ACQUITY UPLC HSS C₁₈ column (2.1 × 50 mm, 1.8 μm) at 30°C using gradient elution with water/formic acid (1%) and acetonitrile at a flow rate of 0.4 mL/min. A total of 11 chemical constituents of Ganmaoling granule were identified from their molecular weight, UV spectra, tandem mass spectrometry data, and retention behavior by comparing the results with those of the reference standards or literature. And 25 peaks were selected as the common peaks for fingerprint analysis to evaluate the similarities among 25 batches of Ganmaoling granule. The results of principal component analysis and orthogonal projection to latent structures discriminant analysis showed that the important chemical markers that could distinguish the different batches were revealed as 4,5‐di‐O‐caffeoylquinic acid, 3,5‐di‐O‐caffeoylquinic acid, and 4‐O‐caffeoylquinic acid. This is the first report of the ultra high performance liquid chromatography chemical fingerprint and component identification of Ganmaoling granule, which could lay a foundation for further studies of Ganmaoling granule.     

High‐performance liquid chromatography based chemical fingerprint analysis and chemometric approaches for the identification and distinction of three endangered Panax plants in Southeast Asia

Among Panax genus, only three endangered species Panax notoginseng, P. vietnamensis, and P. stipuleanatus that have a similar morphology are mainly distributed in Southeast Asia. These three plants are usually misidentified or adulterated. To identify them well, their chemical chromatographic fingerprints were established by an effective high‐performance liquid chromatography method. By comparing the chromatograms, the three Panax species could be distinguished easily using the 22 characteristic peaks. Besides, the data of the chromatographic fingerprints aided by chemometric approaches were applied for the identification and investigation the relationship of different samples and species. Using similarity analysis, the chemical components revealed higher similarity between P. vietnamensis and P. stipuleanatus. The results of hierarchical clustering analysis indicated that samples belonging to the same species could be clustered together. The result of principal component analysis was similar with hierarchical clustering analysis and the three principal components accounted for >80.5% of total variability.     

Simultaneous separation and determination of phenolic acids,pentapeptides, and triterpenoid saponins in the root of Aster tataricus by high‐performance liquid chromatography coupled with electrospray ionization quadrupole time‐of‐flight mass spectrometry

We established a qualitative method to analyze the main chemical compositions of the root of Aster tataricus. Most of the peaks were separated on a C₁₈ column packed with 5.0 μm particles, and 28 compounds were identified, including 11 chlorogenic acids, ten astins/asterinins, and seven astersaponins, four of which were reported for the first time from A. tataricus. Furthermore, we developed a reliable method for the simultaneous quantification of 3‐caffeoylquinic acid, 3,4‐dicaffeoylquinic acid, 3,5‐dicaffeoylquinic acid, astin A, astin B, astin C, astersaponin A, and astersaponin C, and the qualified separations were achieved only on a C₁₈ column packed with 2.7 μm particles. The method was used to measure the concentrations of eight components in samples from two major producing areas in China, and the average contents in samples from Bozhou (Anhui) were higher than those in samples from Anguo (Hebei).     

Quality evaluation of Hpericum japomicum by using high‐performance liquid chromatography coupled with photodiode array detector and electrospray ionization tandem mass spectrometry

A high‐performance liquid chromatography coupled with photodiode array detection and electrospray ionization tandem mass spectrometry (HPLC‐PAD‐ESI‐MSⁿ) method was developed to evaluate the quality of Hpericum japomicum through establishing chromatographic fingerprint and simultaneous determination of seven phenolic compounds. The analysis was achieved on an Ultimate XB‐C₁₈ analytical column (250 mm × 4.6 mm i.d., 5 µm) using an aqueous solution of acetic acid (pH 3.8) and methanol as the mobile phase. Ten samples of H. japomicum from various habitats were investigated and the correlation coefficients of similarity were determined from the HPLC fingerprints. By using an online ESI‐MSⁿ, 20 common peaks in chromatographic fingerprints were identified as phenols, including flavones and their glycosides, flavonones and their glucosides, flavanols, xanthones, phloroglucinols, phenyl propanoids and chromones. Based on the above study, seven phenols which are considered to be major constituents in H. japomicum, including 3,4‐dihydroxybenzoic acid (1), taxfolin‐7‐O‐α‐l ‐rhamnoside (7), 7‐dihydroxy‐2‐(1‐methylpropyl)chromone‐8‐β‐d ‐glucoside (8), isoquercitrin (14), quercitrin (16), quercetin‐7‐O‐α‐l‐ rhamnoside (18) and quercetin (19) were quantified by the validated HPLC‐PAD method. This developed method by combination of chromatographic fingerprint and quantification analysis could be applied to control the quality of H. japomicum. Copyright © 2009 John Wiley & Sons, Ltd.     

Qualitative and quantitative analysis of multiple components for quality control of Deng‐Zhan‐Sheng‐Mai capsules by ultra high performance liquid chromatography tandem mass spectrometry method coupled with chemometrics

Deng‐Zhan‐Sheng‐Mai capsules are a well‐known traditional Chinese patent medicine that was developed in China for the treatment of ischemic stroke. Its quality control focuses on Erigerontis Herba but ignores the contributions of Ginseng Radix et Rhizoma, Schisandrae Chinensis Fructus, and Ophiopogonis Radix. To improve the quality standards for this medicine, this work reports the application of a systematic ultra high performance liquid chromatography tandem mass spectrometric method coupled with chemometrics. Three qualitative and quantitative parameters are established for the evaluation of quality: chemical profiling, the relationship between the contents of 18 compounds and the antioxidant activity, and chemometric analysis. A total of 55 compounds, including 20 phenolic acids, 10 flavonoids, 15 saponins, and 10 lignans, were identified. The method for the quantitative determination of the aforementioned 18 compounds was validated. The limit of quantification ranged from 0.13 to 9.60 ng/mL. The overall recoveries ranged from 95.31 to 103.54%. Hierarchical cluster analysis and principal component analysis were applied to the data of 18 components in ten batches of samples. Nine compounds, including scutellarin, 3,5‐O‐dicaffeoylquinic acid, 4,5‐O‐dicaffeoylquinic acid, ginsenoside Rb1, ginsenoside Re, ginsenoside Rg1, ophiopogonin D, schisandrin, and schisandrol B, are suggested as chemical markers for evaluating the quality.     

Integrated evaluation of HPLC and UV fingerprints for the quality control of Danshen tablet by systematic quantified fingerprint method combined with antioxidant activity

Danshen tablet, which consists of Salviae Miltiorrhizae Radix et Rhizoma, Notoginseng Radix et Rhizoma and Borneolum syntheticum , has been widely used in the therapy of cardiovascular disease. The aim of this study was to develop comprehensive evaluation methods for the quality control of Danshen tablet. First, five‐wavelength fusion fingerprint was established to avoid one‐sidedness of a single wavelength. Then, the ultraviolet spectrum fingerprint was applied to reflect the information of unsaturated bond and conjugated system of chemical substances in Danshen tablet. The similarity analyses of these two fingerprints were performed by systematic quantified fingerprint method in terms of qualitative and quantitative aspects. After that, the evaluation results of high‐performance liquid chromatography and ultraviolet fingerprints were integrated by the mean algorithm, which could reduce the error caused by single method. The integrated evaluation results showed that 30 batches of samples were classified into seven grades. Finally, the fingerprint–efficacy relationship was established using an on‐line antioxidant system and partial least‐squares model to explore the connection between chemical components and antioxidant activities. The methods established in this paper were found suitable for the analysis of Danshen tablet.     

Comparative chemical fingerprinting of Oroxylum indicum and Scutellaria baicalensis using liquid chromatography and mass spectrometry

Introduction: Identification of Oroxylum indicum and Scutellaria baicalensis provides an interesting challenge in selection of biomarker compound to be used in routine analysis. Both plants have similar phytochemical profile and are rich sources of flavones and flavone glycosides. The objective of this study was to prepare the chemical fingerprinting of O. indicum bark and S. baicalensis roots using the liquid chromatography and mass spectroscopy in single chromatographic method. Materials and methods: Extracts prepared using various solvent systems (methanol, aqueous methanol, chloroform, hexane, and water) of both plants were analyzed using C18 reverse phase column with solvent system containing acetonitrile and 0.1% formic acid. Major flavonoids were identified based on mass spectra, fragmentation pattern, and UV spectra. Results: In this article, well-resolved high-performance liquid chromatographic (HPLC) separation in both plant extracts was obtained and chemical fingerprints for both plant extracts were established and flavonoids present (baicalin, oroxylin A-7-O-glucuronide, chrysin-7-O-glucuronide, baicalein, chrysin, oroxylin-A, wogonin, skullcap flavone II) were identified as possible biomarkers. Conclusion: Mass spectrometry coupled with HPLC can be a tool for fingerprinting of various natural products used in dietary supplement industry. The fingerprint developed in the article can be used for quality evaluation as well as identifying possible adulteration of extracts of both the plants.     

Ultra‐high‐performance liquid chromatography with tandem mass spectrometry method for determination of four compounds in rat plasma after oral administration of Xanthii fructus and stir‐fried Xanthii fructus extracts

Xanthii fructus (XF), the fruit of Xanthium sibiricum Patr., is a traditional Chinese materia medica commonly used to treat allergic rhinitis and other rhinitis diseases. To uncover the mechanism of the stir‐frying process and its effect on the pharmacokinetic behavior of active compounds in model rats, four active compounds—chlorogenic acid, 4‐caffeoylquinic acid, 1,5‐O‐dicaffeoylquinic acid and apigenin—were selected based on previous spectrum‐effect experiments. High performance liquid chromatography tandem triple quadrupole mass spectrometry (UPLC–QqQ–MS) technology, an accurate and feasible method, was applied to measure the concentration of these four compounds in rat plasma. This validated method can accurately measure the concentration of each compound at each sampling point of rat plasma. This validated method shows good linearity, extraction recoveries, matrix effects, intra‐ and inter‐day precision and stabilities. Compared with the XF group, the maximum plasma concentration (C_max) value of 1,5‐O‐dicaffeoylquinic acid decreased remarkably (p < 0.05) after oral administration of stir‐fried Xanthii fructus (SXF) extract, while the other compounds showed no significant difference. The mean residence time value of chlorogenic acid (p < 0.05) and 1,5‐O‐dicaffeoylquinic acid (p<0.01) after oral administration of SXF extraction demonstrated significant differences compared with the XF group, while the other two compounds showed no statistical difference, indicating that the stir‐frying process prolonged the effect time and delayed the removal time of chlorogenic acid and 1,5‐O‐dicaffeoylquinic acid. The values of the area under the plasma concentration–time curve from zero to the last quantifiable time‐point, the area under the plasma concentration–time curve from zero to infinity, the time to maximum concentration and the elimination half‐life of four compounds in the SXF group showed no statistically significant difference from the XF group. From this data, we speculated that the stir‐frying process can not only keep the absorption of 4‐caffeoylquinic acid and apigenin, but also increase the effect time of chlorogenic acid and 1,5‐O‐dicaffeoylquinic acid, which could be the mechanism underlying the stir‐frying process enhancing the effects of XF.     

Evaluation of the chemical consistency of Yin‐Chen‐Hao‐Tang prepared by combined and separated decoction methods using high‐performance liquid chromatography and quadrupole time‐of‐flight mass spectrometry coupled with multivariate statistical analysis

In this study, Yin‐Chen‐Hao‐Tang prepared by two decoction methods, namely, combined decoction (modern decoction method) and separated decoction (traditional decoction method), was analyzed by high‐performance liquid chromatography with quadrupole time‐of‐flight mass spectrometry. The acquired datasets containing sample codes, t_R‐m/z pairs and ion intensities were processed with multivariate statistical analyses, such as principal component analysis and an orthogonal partial least squared discriminant analysis model, to globally compare the chemical differences between the different decoction samples. Then, the chemical differences between the combined and separated decoctions were screened out by S‐plots generated from the orthogonal partial least squared discriminant analysis model and compared with chemical information from an established in‐house library. The six components that contributed the most to the chemical differences were identified as chlorogenic acid, caffeic acid, geniposide, genipin, scopoletin, and 3,5‐dicaffeoylquinic acid. The concentrations of genipin and caffeic acid from the separated decoction were higher than those from the combined decoction, indicating that the separated decoction may present a stronger hepatoprotective effect. However, the results still require further investigation through pharmacological and clinical studies. Our findings not only establish a strategy to evaluate chemical consistency of Yin‐Chen‐Hao‐Tang but also provide the scientific basis for using traditional separated decoction method.     

Identification and evaluation of the chemical similarity of Yindan xinnaotong samples by ultra high performance liquid chromatography with quadrupole time‐of‐flight mass spectrometry fingerprinting

Yindan xinnaotong, a compound preparation used in traditional Chinese medicine, is composed of eight herbs: Ginkgo biloba leaf (yinxingye), Salvia miltiorrhizae (danshen), Herba gynostemmatis (jiaogulan), Erigerontis herba (dengzhanxixin), Allii sativi bulbus (dasuan), Notoginseng radixe rhizoma (sanqi), Crataegi fructus (shanzha), and Borneolum (tianranbingpian). Yindan xinnaotong is primarily used to treat cardiovascular and cerebrovascular diseases. However, to date, no scientific methods have been established to assess the quality of Yindan xinnaotong. Therefore, a combinatorial method was developed based on chemical constituent identification and fingerprint analysis to assess the consistency of Yindan xinnaotong quality. In this study, ultra high performance liquid chromatography coupled with time‐of‐flight mass spectrometry was used to identify the chemical components of Yindan xinnaotong soft capsules. Approximately 74 components were detected, of which 70, including flavonoids, ginkgolide, phenolic acid, diterpenoid tanshinones, and ginsenoside, were tentatively identified. A fingerprint analysis was also conducted to evaluate the uniformity of the quality of Yindan xinnaotong soft capsules. Ten batches of Yindan xinnaotong soft capsules were analyzed. All of the resulting chromatograms were imported into the “Similarity Evaluation System for Chromatographic Fingerprints of TCM” (Chinese Pharmacopoeia Commission, version 2004A). The similarity scores of common peaks from these samples ranged from 0.903–1.000, indicating that samples from different batches were highly correlated.     

Hierarchical scheme for liquid chromatography/multi‐stage spectrometric identification of 3,4,5‐triacyl chlorogenic acids in green Robusta coffee beans

Liquid chromatography/multi‐stage spectrometry (LC/MSⁿ) (n = 2–4) has been used to detect and characterize in green Robusta coffee beans eight quantitatively minor triacyl chlorogenic acids with seven of them not previously reported in nature. These comprise 3,4,5‐tricaffeoylquinic acid (Mr 678); 3,5‐dicaffeoyl‐4‐feruloylquinic acid, 3‐feruloyl‐4,5‐dicaffeoylquinic acid and 3,4‐dicaffeoyl‐5‐feruloylquinic acid (Mr 692); 3‐caffeoyl‐4,5‐diferuloylquinic acid and 3,4‐diferuloyl‐5‐caffeoylquinic acid (Mr 706); and 3,4‐dicaffeoyl‐5‐sinapoylquinic acid and 3‐sinapoyl‐4,5‐dicaffeoylquinic acid (Mr 722). Structures have been assigned on the basis of LC/MSⁿ patterns of fragmentation. A new hierarchical key for the identification of triacyl quinic acids is presented, based on previously established rules of fragmentation. Fifty‐two chlorogenic acids have now been characterized in green Robusta coffee beans. In this study five samples of green Robusta coffee beans and fifteen samples of Arabica coffee beans were analyzed with triacyl chlorogenic acids only found in Robusta coffee bean extracts. These triacyl chlorogenic acids could be considered as useful phytochemical markers for the identification of Robusta coffee beans. Copyright © 2010 John Wiley & Sons, Ltd.     

Simultaneous chemical fingerprint and quantitative analysis of Rhizoma Smilacis Glabrae by accelerated solvent extraction and high‐performance liquid chromatography with tandem mass spectrometry

Rhizoma Smilacis Glabrae (RSG) is a well‐known herbal medicine with the homology of medicine and food. In this study, simultaneous chemical fingerprint and quantitative analysis of the bioactive flavonoid components of RSG were developed using accelerated solvent extraction and high‐performance liquid chromatography coupled with ion trap tandem mass spectrometry. The operational parameters of accelerated solvent extraction including extraction solvent, extraction temperature, static extraction time, solid‐to‐liquid ratio, and extraction cycles were optimized. Hierarchical cluster analysis, similarity analysis, and principal component analysis were performed to evaluate the similarity and variation of the samples collected from several provinces in China. Subsequently, high‐performance liquid chromatography fingerprints were established for the discrimination of 16 batches of RSG samples, and the major six flavonoids, namely, toxifolin, neoastilbin, astilbin, neoisoastilbin, isoastilbin, and engeletin were then quantitatively determined. The calibration curves for all the six analytes showed good linearity (r² > 0.999), and the limits of detection and quantification were less than 0.10 and 0.27 μg·mL^?1, respectively. Therefore, the proposed extraction and determination methods were proved to be robust and reliable for the quality control of RSG.     

Chemical fingerprint and quantitative analysis for the quality evaluation of Vitex negundo seeds by reversed‐phase high‐performance liquid chromatography coupled with hierarchical clustering analysis

A simple and efficient method was developed for the chemical fingerprint analysis and simultaneous determination of four phenylnaphthalene‐type lignans in Vitex negundo seeds using high‐performance liquid chromatography with diode array detection. For fingerprint analysis, 13 V. negundo seed samples were collected from different regions in China, and the fingerprint chromatograms were matched by the computer‐aided Similarity Evaluation System for Chromatographic Fingerprint of TCM (Version 2004A). A total of 21 common peaks found in all the chromatograms were used for evaluating the similarity between these samples. Additionally, simultaneous quantification of four major bioactive ingredients was conducted to assess the quality of V. negundo seeds. Our results indicated that the contents of four lignans in V. negundo seeds varied remarkably in herbal samples collected from different regions. Moreover, the hierarchical clustering analysis grouped these 13 samples into three categories, which was consistent with the chemotypes of those chromatograms. The method developed in this study provides a substantial foundation for the establishment of reasonable quality control standards for V. negundo seeds.     

Multi‐constituent determination and fingerprint analysis of Scutellaria indica L. using ultra high performance liquid chromatography coupled with quadrupole time‐of‐flight mass spectrometry

An ultra‐performance liquid chromatography coupled with quadrupole time‐of‐flight mass spectrometry method integrating multi‐constituent determination and fingerprint analysis has been established for quality assessment and control of Scutellaria indica L. The optimized method possesses the advantages of speediness, efficiency, and allows multi‐constituents determination and fingerprint analysis in one chromatographic run within 11 min. 36 compounds were detected, and 23 of them were unequivocally identified or tentatively assigned. The established fingerprint method was applied to the analysis of ten S. indica samples from different geographic locations. The quality assessment was achieved by using principal component analysis. The proposed method is useful and reliable for the characterization of multi‐constituents in a complex chemical system and the overall quality assessment of S. indica.     

Accurate discrimination of Gastrodia elata from different geographical origins using high‐performance liquid chromatography fingerprint combined with boosting partial least‐squares discriminant analysis

Gastrodia elata from different geographical origins varies in quality and pharmacological activity. This study focused on the classification and identification of Gastrodia elata from six producing areas using high‐performance liquid chromatography fingerprint combined with boosting partial least‐squares discriminant analysis. Before recognition analysis, a principal component analysis was applied to ascertain the discrimination possibility with high‐performance liquid chromatography fingerprints. And then, boosting partial least‐squares discriminant analysis and conventional partial least‐squares discriminant analysis were applied in this study. Experimental results indicated that the adaptive iteratively reweighted penalized least‐squares algorithm could eliminate the baseline drift of high‐performance liquid chromatography chromatograms effectively. And compared with partial least‐squares discriminant analysis, the total recognition rates using high‐performance liquid chromatography fingerprint combined with boosting partial least‐squares discriminant analysis for the calibration sets and prediction sets were improved from 94 to 100% and 86 to 97%, respectively. In conclusion, high‐performance liquid chromatography combined with boosting partial least‐squares discriminant analysis, which has such advantages as effective, specific, accurate, non‐polluting, has an edge for discrimination of traditional Chinese medicine from different geographical origins. And the proposed methodology is a useful tool to classify and identify Gastrodia elata from different geographical origins.     

Fingerprint analysis,multi‐component quantitation,and antioxidant activity for the quality evaluation of Salvia miltiorrhiza var. alba by high‐performance liquid chromatography and chemometrics

Salvia miltiorrhiza Bge. var. alba C.Y. Wu and H.W. Li has wide prospects in clinical practice. A useful comprehensive method was developed for the quality evaluation of S. miltiorrhiza var. alba by three quantitative parameters: high‐performance liquid chromatography fingerprint, ten‐component contents, and antioxidant activity. The established method was validated for linearity, precision, repeatability, stability, and recovery. Principal components analysis and hierarchical clustering analysis were both used to evaluate the quality of the samples from different origins. The results showed that there were category discrepancies in quality of S. miltiorrhiza var. alba samples according to the three quantitative parameters. Multivariate linear regression was adopted to explore the relationship between components and antioxidant activity. Three constituents, namely, danshensu, rosmarinic acid, and salvianolic acid B, significantly correlated with antioxidant activity, and were successfully elucidated by the optimized multivariate linear regression model. The combined use of high‐performance liquid chromatography fingerprint analysis, simultaneous multicomponent quantitative analysis, and antioxidant activity for the quality evaluation of S. miltiorrhiza var. alba is a reliable, comprehensive, and promising approach, which might provide a valuable reference for other herbal products in general to improve their quality control.     

Chemical interaction between Paeonia lactiflora and Glycyrrhiza uralensis,the components of Jakyakgamcho‐tang,using a validated high‐performance liquid chromatography method: Herbal combination and chemical interaction in a decoction

The herbal combination is the basic unit of a herbal formula that affects the chemical characteristics of individual herbs. In the present study, a method of simultaneous determination of the 11 marker compounds in Jakyakgamcho‐tang was developed using high‐performance liquid chromatography with photodiode array detection. The validated analytical method was successfully applied to approach the chemical interaction between Paeonia lactiflora and Glycyrrhiza uralensis in co‐decoction. In P. lactiflora, the contents of gallic acid, oxypaeoniflorin, (+)‐catechin, paeoniflorin, and benzoylpaeoniflorin were decreased, while those of albiflorin and benzoic acid were increased; in G. uralensis, the contents of liquiritin, isoliquiritin, ononin, and glycyrrhizin were decreased, when decocting two herbs together. Moreover, as the ratio between P. lactiflora and G. uralensis was increased, the contents of chemical contents from each herb were proportionally increased. However, each content of marker compound per the gram of herbal medicine was decreased as the ratio of combinative herbs increased. The results showed that P. lactiflora and G. uralensis affect the extraction efficiency of chemical compounds in a Jakyakgamcho‐tang decoction. Overall, the method established in this study was simple, rapid, and accurate, and would be useful for the determination of marker compounds and for the investigation of the chemical interaction between herbal medicines.     

Identification of Salvia species using high‐performance liquid chromatography combined with chemical pattern recognition analysis

Salvia miltiorrhiza, also known as Danshen, is a widely used traditional Chinese medicine for the treatment of cardiovascular diseases and hematological abnormalities. The root and rhizome of Salvia przewalskii and Salvia yunnanensis have been found as substitutes for Salvia miltiorrhiza in the market. In this study, the chemical information of 14 major compounds in Salvia miltiorrhiza and its substitutes were determined using a high‐performance liquid chromatography method. Stepwise discriminant analysis was adopted to select the characteristic variables. Partial least squares discriminant and hierarchical cluster analysis were performed to classify Salvia miltiorrhiza and its substitutes. The results showed that all of the samples were correctly classified both in partial least squares discriminant analysis and hierarchical cluster analysis based on the four compounds (caffeic acid, rosmarinic acid, salvianolic acid B, and salvianolic acid A). This method can not only distinguish Salvia miltiorrhiza and its substitutes, but also classify Salvia przewalskii and Salvia yunnanensis. The method can be applied for the quality assessment of Salvia miltiorrhiza and identification of unknown samples.     

Quality evaluation of Salvia miltiorrhiza Bge. by ultra high performance liquid chromatography with photodiode array detection and chemical fingerprinting coupled with chemometric analysis

An ultra high performance liquid chromatography with photodiode array detection method is developed for the simultaneous quantitative determination of five water‐soluble compounds including danshensu, protocatechualdehyde, rosmarinic acid, salvianolic acid B, and salvianolic acid A in Salvia miltiorrhiza Bge. samples. Through method optimization, the five compounds all expressed good linearity (R² > 0.9990) in a wide concentration range together with satisfactory accuracy, precision, and stability. Moreover, through qualitative analysis of the chemical fingerprint combined with similarity analysis, hierarchical cluster analysis, principle component analysis, and partial least‐squares discriminate analysis, we determined that the 13 batches of Salvia miltiorrhiza Bge. were similar in internal quality and the differences resulted from various cultivation environments, recovery elements, and others. Seen from the results of hierarchical cluster analysis and principle component analysis, the classification of 13 batches was in accordance, and partial least‐squares discriminate analysis technique was more suitable than the principle component analysis model to provide a distinct classification of test samples on the basis of their different components. Moreover, a permutation test verified the rationality of partial least‐squares discriminate analysis and variable importance plot showed that peaks 37 and 38 were the most significant variables in distinguishing the Salvia miltiorrhiza Bge. samples. The idea of the quantitative and qualitative analysis of Salvia miltiorrhiza Bge. was convenient, sensitive, and comprehensive, which could be applied to evaluate the quality of more traditional Chinese medicines.