Differentiation of rhizoma et radix polygoni cuspidati from closely related herbs by HPLC fingerprinting

An HPLC-DAD fingerprinting profile of Rhizoma Et Radix Polygoni Cuspidati was established basing on the consistent chromatographic features of 24 authentic herb samples. The major types of chemical constituents, stilbenes and anthraquinones, were analyzed and included in the fingerprint. Eight common peaks of Polygonum Cuspidatum were identified by using HPLC-MS. The developed fingerprint was applied to differentiate Rhizoma Et Radix Polygoni Cuspidati from Radix Polygoni Multiflori and Radix Et Rhizoma Rhei. Although the three herbs belong to the family of Polygonaceae, the results indicated that these could be differentiated by using the established method.     

Capillary high-performance liquid chromatography with mass spectrometry for simultaneous determination of major flavonoids, iridoid glucosides and saponins in Flos Lonicerae

Flos Lonicerae, a traditional herbal medicine, has been used in China to treat some inflammatory disease. Several different classes of compounds have been separated from the herb to assess their pharmacological activities. Among these classes, flavonoids, iridoid glycosides and saponins have been well studied and may be responsible for its clinical application. Therefore, quality control of Flos Lonicerae is an important issue for drug safety and validity evaluations. A quantitative method consisting of solid phase extraction followed by capillary high-performance liquid chromatography-diode array detection/electrospray ionization mass spectrometry (capillary HPLC-DAD/ESI-MS) was developed for simultaneously assay of 24 compounds in Flos Lonicerae. Under optimized capillary HPLC-DAD/ESI-MS conditions, these compounds, including nine flavonoids, eight iridoid glucosides and seven saponins, were separated with high efficiency in the selected-ion monitoring (SIM) mode. Linearity of the method was good with correlation coefficients (r(2)) in the range of 0.9935-0.9998 and detection limits were lower than 2.57 ng/mL for most of analytes. The obtained recoveries varied between 91.0 and 108.7% with the relative standard deviations (RSDs) within 8.74% (n=3). The capillary HPLC-DAD/ESI-MS method was also successfully applied to the analysis of these compounds in five species of Flos Lonicerae. It was demonstrated to be a powerful tool for comprehensive analysis of herbal medicines, owing to its exclusive selectivity and excellent sensitivity.     

Two-dimensional thin-layer chromatography of selected Polygonum sp. extracts on polar-bonded stationary phases

Two-dimensional thin-layer chromatographic systems on cyano-bonded polar stationary phases were used for the separation of some phenolic compounds extracted from two species of Polygonum: Polygonum hydropiper L. and Polygonum cuspidatum L. Non-aqueous solvents were used in the first direction and aqueous solvents were used in the second direction on CN silica TLC plates. For the separation of phenolics' standards optimal chromatographic systems were chosen from the retention data collected in one-dimensional TLC experiments by plotting graphs of R(F) vs. R(F) dependencies. Using above described method the satisfactory results of separations were obtained.     

Principal component analysis in interpretation of the results of HPLC-ELC, HPLC-DAD and essential elemental contents obtained for medicinal plant extracts

Principal component analysis (PCA) was applied to compare its usefulness with cluster analysis (CA), and factorial k-means analysis (fkm), for evaluating the results obtained using HPLC-DAD, HPLC-ELC and spectroscopic techniques (AAS and UV/VIS spectrometry for determining content of N, P, Fe and Cu) in aqueous extracts of seven medicinal plants. These represented the following plant species that are rich in flavonoids: Betula verrucosa Ehrh., Equisetum arvense L., Polygonum aviculare L., Viola tricolor L., Crataegus oxyacantha L., Sambucus nigra L. and Helichrysum arenarium (L.) Moench. The databases analyzed comprised four sets: 1) results obtained by the use of HPLC-DAD detection, 2) results obtained by the use of electrochemical detection (HPLC-ELC), 3) results for determining elements — total and water-extractable species, and 4) all data combined. Application of statistical methods allowed the samples to be classified into four groups: 1) Crataegus, Sambucus, 2) Equisetum, Polygonum and Viola, 3) Betula, and 4) Helichrysum, which were differentiated by characteristic patterns. PCA supported by CA, was the most suitable method, because it simultaneously allowed for reduction of multidimensionality of the databases, grouped the samples into four clusters, and made possible selection of the factors responsible for differentiation of the plant materials studied.      

Multi-component HPLC fingerprinting of Radix Salviae Miltiorrhizae and its LC-MS-MS identification

The multi-component fingerprinting method of Radix Salviae Miltiorrhizae (Root of Salvia miltiorrhiza BGE.), an important and popular medicinal herb in traditional Chinese medicine, was studied using reverse-phase HPLC and LC-MS-MS. Extract containing both the water-soluble phenolic compounds and nonpolar diterpenoid compounds known to be the herb's main bioactive components was prepared by a two-step extractive procedure. An HPLC fingerprinting method which can simultaneously separate these two types of compounds was established with gradient elution mode and photodiode array detection at 280 nm. Eighteen peaks in this HPLC fingerprint were structurally identified by employing LC-MS-MS techniques. The electrospray ionization (ESI) MS-MS spectra of most salvianolic acids displayed a characteristic behavior of loss of danshensu and caffeic acid moieties, while those of tanshinones showed a particular behavior of loss of H2O which is quite different from the fragmentation pattern in electron ionization mass spectrometry (EI-MS). The HPLC fingerprints of 7 batches of crude drugs showed similar separation pattern and provided much chemical information of the pharmacologically-active compounds in the crude drugs, which is useful for the authentication and quality evaluation of this medicinal herb.     

LC Fingerprint and Hierarchical Cluster Analysis of Crocus sativus L. from Different Locations in China

Using simple, sensitive and specific column liquid chromatography, a chemical fingerprinting method was developed for investigating and demonstrating the variance of chemical components among different populations of Crocus sativus L., from 15 locations in China. The LC assay was performed on a reversed-phase C₁₈ column with linear gradient elution using methanol and 1% aqueous acetic acid. The LC data showed considerable variation of chemical constituents among C. sativus populations. Four chemotypes were visually developed from the chromatographic profiles. The grouping of 15 C. sativus populations in hierarchical clustering analysis was in good agreement with the visual comparison of their chromatograms, as demonstrated by chemotypes. In addition, the bioactive compound crocin 1 in this herb was quantitatively determined by a validated reversed-phase LC analysis. Relative peak areas of characteristic compounds were also calculated for quantitative expression of the LC fingerprints. These results showed that the established method for fingerprinting analysis was considered to be suitable for the quality control of C. sativus.     

Characterization of phenolic acids and flavonoids in dandelion (Taraxacum officinale WEB. ex WIGG.) root and herb by high-performance liquid chromatography/electrospray ionization mass spectrometry

Phenolic acids and flavonoids were extracted from a dandelion (Taraxacum officinale WEB. ex WIGG.) root and herb juice and characterized by high-performance liquid chromatography/electrospray ionization mass spectrometry. Among the 43 compounds detected, 5 mono- and dicaffeoylquinic acids, 5 tartaric acid derivatives, 8 flavone and 8 flavonol glycosides were characterized based on their UV spectra and their fragmentation patterns in collision-induced dissociation experiments. The predominant compound was chicoric acid (dicaffeoyltartaric acid). Furthermore, several caffeoylquinic acid isomers were distinguished in dandelion extracts for the first time by their specific mass spectral data. The present study reveals that even more quercetin glycosides were found in dandelion than hitherto assumed. The occurrence of di- and triglycosylated flavonoids in particular has not yet been described. This paper marks the first report on HPLC-DAD/ESI-MSn investigations of phenolic compounds in dandelion.     

Simultaneous qualitative and quantitative analyses of the major constituents in the rhizome of Ligusticum Chuanxiong using HPLC-DAD-MS

An HPLC-DAD-MS method was developed for the qualitative and quantitative analysis of the major constituents in Chuanxiong (the dried rhizome of Ligusticum chuanxiong Hort). Twenty compounds including phenolic constituents, alkylphthalides and phthalide dimers were identified using online ESI-MS and comparisons with literature data and standard compounds, and six of them were quantified by HPLC-DAD simultaneously. A comprehensive validation of the method including sensitivity, linearity, repeatability and recovery was conducted. The linear regressions were acquired with R(2) > 0.99 and limit of detection (LOD, S/N = 3) values were between 1.5 and 2.5 ng. The repeatability was evaluated by intra- and inter-day assays, and relative standard deviation (RSD) values were reported within 1.87%. The recovery studies for the quantified compounds were observed in the range of 96.36-102.37% with RSD values less than 2.63%. These phenolic constituents and alkylphthalides, the major constituents in Chuanxiong, are generally regarded as the index for the quality assessment of this herb. The overall procedure is accurate and reproducible, which is considered suitable for the qualitative and quantitative analyses of a large number of Chuanxiong samples.     

LC-DAD UV and LC-MS for the Analysis of Isoflavones and Flavones from In Vitro and In Vivo Biomass of Genista tinctoria L.

Conditions were determined for the separation of a complex set of isoflavones and flavones (free aglycones, monoglucosides, diglucosides and esters) by HPLC-DAD UV and MS detection. A good separation of all analytes was obtained and satisfactory peak shapes were achieved by gradient elution on an RP C18 column. The method was then applied to carry out qualitative and quantitative analysis of bioflavonoids present in the herb and in vitro cultures of Genista tinctoria L. Electrospray ionisation mass spectrometry in the negative mode was used to identify individual flavonoids in G. tinctoria plant material. Photodiode array detection was also utilised in flavonoid characterisation. All flavonoid compounds were then quantified using an internal standard. The method developed is useful for monitoring the process of flavonoid biosynthesis in biomass obtained through in vitro cultures.     

Application of HPLC and TLC with diode array detection after SPE to the determination of pesticides in water samples from the Zemborzycki Reservoir (Lublin, southeastern Poland)

The application of TLC with a diode array detector (TLC-DAD) and HPLC-DAD after SPE for identification and quantitative analysis of pesticides in water samples is demonstrated. The procedures described for the determination of compounds are inexpensive and can be applied to routine analysis of analytes in water samples after preliminary cleanup and concentration by SPE. Average recoveries for four different cartridges and three solvents by the proposed HPLC-DAD method after SPE also are presented. The efficiency of the SPE procedure was evaluated using real water samples from the Zemborzycki Reservoir, near Lublin, southeastern Poland. The method was validated for precision, repeatability, and accuracy.     

Separation and characterization of antioxidants from Spirulina platensis microalga combining pressurized liquid extraction, TLC, and HPLC-DAD

A new procedure has been developed to separate and characterize antioxidant compounds from Spirulina platensis microalga based on the combination of pressurized liquid extraction (PLE) and different chromatographic procedures, such as TLC, at preparative scale, and HPLC with a diode array detector (DAD). Different solvents were tested for PLE extraction of antioxidants from S. platensis microalga. An optimized PLE process using ethanol (generally recognized as safe, GRAS) as extraction solvent has been obtained that provides natural extracts with high yields and good antioxidant properties. TLC analysis of this ethanolic extract obtained at 115 degrees C for 15 min was carried out and the silica layer was stained with a DPPH (diphenyl-pycril-hydrazyl) radical solution to determine the antioxidant activity of different chromatographic bands. Next, these colored bands were collected for their subsequent analysis by HPLC-DAD, revealing that the compounds with the most important antioxidant activity present in Spirulina extracts were carotenoids, as well as phenolic compounds and degradation products of chlorophylls.     

Biological fingerprinting analysis by liquid chromatography/mass spectrometry for evaluation of DNA structural selectivity of multiple compounds in natural products

A method by combination of centrifugal ultrafiltration (CUF) sampling with liquid chromatography-mass spectrometry (LC-MS) analysis was established to evaluate the DNA structure and sequence selectivity of the multiple compounds in a small molecule library. The developed method was applied to analyze the extracts of natural products Coptis chinensis Franch and Rheum palmatum (L.). From the obtained biological fingerprinting chromatograms, 7 compounds in C. chinensis Franch and 11 in R. palmatum (L.) were screened out as DNA binding agents. Most of these compounds were identified by standards and LC-MS analysis after the sample pretreatment with the DNA immobilized cartridge. DNA structural binding preference of the multiple active compounds in these two extracts was then evaluated simultaneously without purification.     

Qualitative and Quantitative Analysis for the Quality Control of Rhizoma Coptidis by HPLC-DAD and HPLC-ESI-MS

For quality control purpose, an approach of fingerprinting and simultaneous quantification of five major bioactive constituents of Rhizoma Coptidis was established via a high-performance liquid chromatograph coupled with a photodiode array UV detector(HPLC-DAD) and an electrospray ionization mass spectrometer(HPLC-ESI/MS). The compounds were identified on the basis of the comparison of their mass spectra with literature data and those of standard samples and quantified by the HPLC-DAD method. Baseline separation was achieved on an XTerra C 18 column(5 μm, 250 mm×4.6 mm i. d.) with linear gradient elution of formate buffer(consisting of 0.5% formic acid, adjusted to pH=4.5 with ammonia) and acetonitrile(consisting of 0.2% formic acid and 0.2% triethylamine). The me-thod was validated for linearity(r 2 0.9995), repeatability(RSD3.1%), intra-and inter-day precision(RSD1.8%) with recovery(99.9%―105.1%), limits of detection(0.15―0.35 μg/mL), and limits of quantification(0.53―0.82 μg/mL). The similarities of 32 batches of Rhizoma Coptidis and their classification according to their manufacturers were based on the retention time and peak areas of the characteristic compounds. The five compounds were selected for quality assessment of Rhizoma coptidis via partial least squares analysis(PLS).     

The Potential Use of Herbal Fingerprints by Means of HPLC and TLC for Characterization and Identification of Herbal Extracts and the Distinction of Latvian Native Medicinal Plants

The growing market of herbal medicines, the increase in international trade in Latvia, and the lack of adequate analytical methods have raised the question of the potential use of herbal fingerprinting methods. In this study, high-performance liquid chromatography (HPLC) and thin layer chromatography (TLC) methods were developed for obtaining chromatographic fingerprints of four taxonomically and evolutionary different medicinal plants (Hibiscus sabdariffa L., Calendula officinalis L., Matricaria recutita L., Achillea millefolium L.). Retention time shifting, principal component analysis (PCA), hierarchical cluster analysis (HCA), and orthogonal projections to latent structures (OPLS) analysis were used to improve and analyze the obtained fingerprints. HPLC data detection at 270 nm was determined superior to 360 nm for the distinction of medicinal plants and used data alignment method significantly increased similarity between samples. Analyzed medicinal plant extracts formed separate, compact clusters in PCA, and the results of HCA correlated with the evolutionary relationships of the analyzed medicinal plants. Herbal fingerprinting using chromatographic analysis coupled with multivariate analysis has a great potential for the identification of medicinal plants as well as for the distinction of Latvian native medicinal plants.     

直观推导式演进特征投影法分辨枸杞类胡萝卜素的异构体

采用高效液相色谱-二极管阵列检测方法,初步分离了枸杞子中的类胡萝卜素。以乙腈-二氯甲烷(体积比为60∶40)为流动相,流速为1.0 mL/min,用C18柱从枸杞类胡萝卜素中分离出7个峰。但由于类胡萝卜素的结构多样性,尤其是顺反异构体的出现使得分离并不完全。利用所得三维数据提供的信息和化学计量学方法直观推导式演进特征投影法(HELP),对其中某些在二维色谱中被定性为单组分的峰进行解析,结果发现原来在二维色谱中被定性为单组分的峰大多是一些多组分峰。以其中第4个峰为例对其进行解析,得到了该类胡萝卜素的同分异构体色谱流出曲线及紫外光谱信息。该方法表明,化学计量学方法与现代分析手段有机结合,大大降低了此类复杂体系对色谱分离的要求,对同分异构体的分析具有一定的借鉴和指导意义。     

Thin-layer chromatography of 1,2,4-triazoles on silica gel

Summary The TLC behaviour of N-phenyl-1,2,4-triazoles and their derivatives on silica gel plates has been studied using simple solvents. Isomers were very well distinguished, resulting from different activities due to hydrogen bonding. A mixture of seven compounds has been resolved with diethylether-n-butylamine-pyridine (91.4:7.7:0.9).     

Quality evaluation of Rhizoma Belamcandae (Belamcanda chinensis (L.) DC.) by using high-performance liquid chromatography coupled with diode array detector and mass spectrometry

A high-performance liquid chromatography coupled with diode array detector and mass spectrometry (HPLC-DAD-MS) method was developed to evaluate the quality of Rhizoma Belamcandae (Belamcanda chinensis (L.) DC.) through establishing chromatographic fingerprint and simultaneous determination of seven phenolic compounds. The analysis was achieved on an Alltima C(18) analytical column (250 mm x 4.6 mm i.d. 5 microm) using linear gradient elution of acetonitrile-0.1% trifluoroacetic acid. The correlation coefficients of similarity were determined from the HPLC fingerprints, and they shared a close similarity. By using an online APCI-MS/MS, twenty phenols were identified. In addition, seven of these phenols including mangiferin, 7-O-methylmangiferin, tectoridin, resveratrol, tectorigenin, irigenin and irisflorentin were quantified by the validated HPLC-DAD method. These phenols are considered to be major constituents in Rhizoma Belamcandae, and are generally regarded as the index for quality assessment of this herb. This developed method by having a combination of chromatographic fingerprint and quantification analysis could be applied to the quality control of Rhizoma Belamcandae.     

Micellar electrokinetic capillary chromatography fingerprints combined with multivariate statistical analyses to evaluate the quality consistency and predict the fingerprint–efficacy relationship of Salviae miltiorrhizae Radix et Rhizoma (Danshen)

Micellar electrokinetic capillary chromatography fingerprinting combined with quantification was successfully established and applied to evaluate the quality consistency of Danshen, which is a medicinal herb used to treat various diseases, especially coronary cerebrovascular diseases. A background electrolyte composed of 20 mmol/L sodium tetraborate, 90 mmol/L orthoboric acid, 25 mmol/L sodium phosphate monobasic dehydrate, and 65 mmol/L sodium dodecyl sulfate was used to separate compounds. To optimize micellar electrokinetic capillary chromatography conditions, a response surface strategy was set up for orthogonal experimental design. In fingerprint assessments, a systematic quantified fingerprint method was established for integrated quality assessment of Danshen samples from qualitative and quantitative perspectives, by which the quality of 30 samples was well differentiated. The principal component analysis coupled with quantitative determination of two components was applied to explain that the quality consistency of the medicinal herb was relatively good within one harvest season, but poor among harvest seasons for the Danshen samples. In addition, the fingerprint–efficacy relationship between the chemical fingerprints and antioxidant activities was investigated utilizing orthogonal projection to latent structures, which provided important medicinal efficacy information for quality control. This work offered an efficient, holistic, and powerful approach to evaluate the quality consistency of Danshen samples.     

Comparison of the volatile constituents of Artemisia capillaris from different locations by gas chromatography-mass spectrometry and projection method

The volatile chemical constituents of Artemisia capillaries (an important traditional Chinese medicine) were determined by gas chromatography-mass spectrometry (GC-MS) and sub-window factor analysis (SFA). Seventy-five components were separated and 43 of them were qualitatively and quantitatively determined, which represented about 89.03% of the total content. This profile was then used to identify and assess the consistency of the herb by using an orthogonal projection method. Four different sources of A. capillaries were analyzed and compared with each other. Among the components determined, there were 51 components coexisting in all samples although the relative peak areas of a few showed variations. It is the first time to apply orthogonal projection method to the comparison of different samples, and it reduces the burden of qualitative analysis as well as the subjectivity. The results showed a fair consistency in their GC-MS fingerprint. A. capillaris was distinguished from Artemisia sacrorum L., a possible substitute in traditional Chinese medicine by comparing the fingerprints with each other.     

Ecosystem discrimination and fingerprinting of Romanian propolis by hierarchical fuzzy clustering and image analysis of TLC patterns

The fingerprinting capacity of thin layer chromatography (TLC) and image analysis in the case of propolis samples collected in different area in Romania has been investigated. Fuzzy divisive hierarchical clustering approach was used as a powerful tool of samples discrimination and fingerprinting according to the geographical origin and local flora. The fuzzy partition and patterns obtained by membership degrees plot were in a very good agreement with floral origin and geographic location of Romanian propolis samples, and clearly illustrate the fuzziness concerning their similarities and difference. The results obtained strongly support that TLC via image analysis can be successfully employed in the fingerprinting methodologies if they are combined with appropriate fuzzy clustering method. The method developed in this paper might be also extended in the authenticity and origin control of fruits, herbs or derived products.