Separation and quantitative analysis of coumarin compounds from Angelica dahurica (Fisch. ex Hoffm) Benth. et Hook. f by pressurized capillary electrochromatography

Chemical Relationship among Genetically Authenticated Medicinal Species of Genus Angelica

The genus Angelica comprises various species utilized for diverse medicinal purposes, with differences attributed to the varying levels or types of inherent chemical components in each species. This study employed DNA barcode analysis and HPLC analysis to genetically authenticate and chemically classify eight medicinal Angelica species (n = 106) as well as two non-medicinal species (n = 14) that have been misused. Nucleotide sequence analysis of the nuclear internal transcribed spacer (ITS) region revealed differences ranging from 11 to 117 bp, while psbA-trnH showed variances of 3 to 95 bp, respectively. Phylogenetic analysis grouped all samples except Angelica sinensis into the same cluster, with some counterfeits forming separate clusters. Verification using the NCBI database confirmed the feasibility of species identification. For chemical identification, a robust quantitative HPLC analysis method was developed for 46 marker compounds. Subsequently, two A. reflexa-specific and seven A. biserrata-specific marker compounds were identified, alongside non-specific markers. Moreover, chemometric clustering analysis reflecting differences in chemical content between species revealed that most samples formed distinct clusters according to the plant species. However, some samples formed mixed clusters containing different species. These findings offer crucial insights for the standardization and quality control of medicinal Angelica species.

Simultaneous Determination of Six Components in Beagle Dog Plasma by UPLC-MS/MS and Its Application to a Comparative Pharmacokinetic Study of Three Different Yuanhu Zhitong Preparations

This study has developed a sensitive, simple, and reliable ultrahigh performance liquid chromatography tandem mass spectrometry method for the simultaneous determination of corydaline, tetrahydropalmatine, tetrahydroberberine, tetrahydrocoptisine, byakangelicin, and byakangelicol in beagle dog plasma after oral administration of Yuanhu Zhitong (YHZT) oral liquid, dispersible tablet, and dropping pills. A one-step protein precipitation method was used with methanol-acetonitrile (50 : 50, v/v) for plasma sample pretreatment. Six analytes and one internal standard were separated on a Waters Acquity UPLC BEH C18 column (2.1 mm × 100 mm, 1.7 μm) by gradient elution with 0.1% formic acid-water and 0.1% formic acid-acetonitrile at a flow rate of 0.4 mL/min. Detection was conducted by multiple reaction monitoring mode in the positive ionization. The calibration curves showed good linearity (r > 0.9920). The lower limit of quantization ranged from 0.1 to 1 ng/mL. Moreover, the other results of the method validation were within the acceptable range. After oral administration, the pharmacokinetic characteristics of the three YHZT preparations were different. Compared with the two solid preparations, the absorption of the six analytes in oral liquid was more rapid. Moreover, the area under the plasma drug concentration-time curve and the maximum plasma concentration of tetrahydropalmatine (the main analgesic component of YHZT prescription) in the oral liquid group were higher than those in the other two groups. The results showed oral liquid can exert its efficacy quickly, while dispersible tablet and dropping pills exhibit relatively slow release pattern. The comparative pharmacokinetic study would be helpful to the clinical rational selection and application of YHZT preparations.

"Q-markers targeted screening" strategy for comprehensive qualitative and quantitative analysis in fingerprints of Angelica dahurica with chemometric methods

Angelica dahurica is a famous functional food and herb. To guarantee quality of A. dahurica, a strategy “Q-markers targeted screening” was successfully developed by sufficient extraction of compounds and the targeted screening of qualitative and quantitative markers calculated through chemometric methods based fingerprints. Accelerated solvent extraction was selected due to its prominent advantages exhibiting the maximum extraction yields and varieties of compounds and especially excellent reproducibility (RSD < 1). After extraction, the fingerprints of A. dahuricae samples were established. For the preliminary herb authenticity, the targeted screening of 23 quantitative markers were performed by similarity analysis and hierarchical cluster analysis based on the fingerprints, which were identified by liquid chromatography tandem mass spectrometry (LC-MS). Subsequently, for further quality control, the targeted screening of nine quantitative markers were done by similarity analysis & linear discriminant analysis, which were determined by LC. Lastly, the strategy was successfully applied to quality assessment of A. dahurica samples.

DES Based Efficient Extraction Method for Bioactive Coumarins from Angelica dahurica (Hoffm.) Benth. & Hook.f. ex Franch. & Sav

In this study, a simple and environmentally friendly method was developed for the extraction of seven active coumarins from Angelica dahurica (Hoffm.) Benth. & Hook.f. ex Franch. & Sav.(A. dahurica) based on deep eutectic solvents (DESs). Among the 16 kinds of DES based on choline chloride, the DES system with the molar ratio of choline chloride, citric acid, and water as 1:1:2 had the best extraction effect. Ultrasonic-assisted response surface methodology (RSM) was used to investigate the optimal extraction scheme. The results showed that the optimal extraction conditions were a liquid–solid ratio of 10:1 (mL/g), an extraction time of 50 min, an extraction temperature of 59.85 °C, and a moisture content of 49.28%. Under these conditions, the extraction yield reached 1.18%. In addition, scanning electron microscopy (SEM) was used to observe the degree of powder fragmentation before and after extraction with different solvents. The cells of A. dahurica medicinal materials obtained by DES ultrasonic-assisted treatment were the most seriously broken, indicating that DES had the highest efficiency in the treatment of A. dahurica. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) DPPH radical scavenging model was used to evaluate the biological activity of DES extract. The results showed that DES extract had better scavenging ability of DPPH free radical. Therefore, DES is a green solvent suitable for extracting coumarin compounds of A. dahurica, with great potential to replace organic solvents.

Potential and applications of capillary electrophoresis for analyzing traditional Chinese medicine: a critical review

Capillary electrophoresis (CE) presents a promising possibility for analyzing traditional Chinese medicine (TCM) due to its low reagent consumption, high analysis speed, and enhanced efficiency. Herein we review the employment of CE for analyzing the effective components in TCM and identifying TCM via a fingerprint. Furthermore, we discuss the application of state-of-the-art capillary electrophoresis modes for screening enzyme inhibitors and investigating the interactions between TCM and plasma proteins. The review concludes with recommendations for future studies and improvements in this field of research. The general development trend identified in this review indicates that the application of CE has significantly improved TCM assay performance.

Ultrasound-assisted extraction extracts from Stemona japonica (Blume) Miq. and Cnidium monnieri (L.) Cuss. could be used as potential Rhipicephalus sanguineus control agents

Nicotiana tabacum, Stemona japonica, and Cnidium monnieri are common plants that are widely used for their anti-parasitic properties. The purpose of this study was to evaluate the acaricidal activity of extracts from these plants against the brown dog tick, Rhipicephalus sanguineus. A composition analysis of crude extracts by GC-MS was conducted to discover compounds with acaricidal effects. The toxicity of extraction against the engorged nymphs of R. sanguineus was evaluated by an immersion test. The results showed that the crude extracts of S. japonica and C. monnieri in varying ratios, concentrations, and from different extraction methods, had a killing effect on R. sanguineus. Lethality reached 76.67% ± 0.04410 when using a 1:1 extract of S. japonica:C. monnieri in 75% ethanol with ultrasonic extraction; the crude extract was determined at a concentration of 0.5 g/mL. GC-MS results showed that osthole and 5-hydroxymethylfurfural (5-HMF) are the main components of the extract. These results suggested that ultrasound-assisted extraction (UAE) extracts contained acaricidal components acting against R. sanguineus, which may result in the development of effective extracts of S. japonica and C. monnieri as a source of low-toxicity, plant-based, natural acaricidal drugs.

Characterization of osthenol metabolism in vivo and its pharmacokinetics

Osthenol, a prenylated coumarin, is a C8-prenylated derivative of umbelliferone isolated from the root of Angelica koreana and Angelica dahurica, an intermediate and is known as a major metabolite of desmethyl-osthole.The various pharmacological effects of osthenol have been reported. In previous studies, we investigated five hydroxylated metabolites by cytochromes P450 (CYP) and glucuronide conjugates of osthenol by uridine diphosphate-glucuronosyltransferases (UGTs). However, osthenol have very few studies have been reported on its pharmacokinetic (PK) profiling, we reported the PK parameters in mouse of osthenol through this study.After oral (5 and 20 mg/kg) and intravenous (5 mg/kg) administration, the concentration of osthenol in plasma was determined by LC-MS/MS. The quantitative method was validated in terms of linearity, accuracy, and precision. When 5 and 20 mg/kg of osthenol were orally administered, the bioavailability (BA) was found to be very low at 0.43 and 0.02%, respectively.In fact, osthenol was mostly metabolized to a two-Phase II conjugates, a sulfonyl and glucuronyl-osthenol, in the blood, which was determined by LC-HR/MS analysis of the blood sample. Because osthenol is rapidly metabolized to two conjugates by first-pass effect the BA of osthenol is low after oral administration.

Characterization of CYPs and UGTs Involved in Human Liver Microsomal Metabolism of Osthenol

Osthenol is a prenylated coumarin isolated from the root of Angelica koreana and Angelica dahurica, and is an O-demethylated metabolite of osthole in vivo. Its various pharmacological effects have been reported previously. The metabolic pathway of osthenol was partially confirmed in rat osthole studies, and 11 metabolic products were identified in rat urine. However, the metabolic pathway of osthenol in human liver microsomes (HLM) has not been reported. In this study, we elucidated the structure of generated metabolites using a high-resolution quadrupole-orbitrap mass spectrometer (HR-MS/MS) and characterized the major human cytochrome P450 (CYP) and uridine 5′-diphospho-glucuronosyltransferase (UGT) isozymes involved in osthenol metabolism in human liver microsomes (HLMs). We identified seven metabolites (M1-M7) in HLMs after incubation in the presence of nicotinamide adenine dinucleotide phosphate (NADPH) and uridine 5′-diphosphoglucuronic acid (UDPGA). As a result, we demonstrated that osthenol is metabolized to five mono-hydroxyl metabolites (M1-M5) by CYP2D6, 1A2, and 3A4, respectively, a 7-O-glucuronide conjugate (M6) by UGT1A9, and a hydroxyl-glucuronide (M7) from M5 by UGT1A3 in HLMs. We also found that glucuronidation is the dominant metabolic pathway of osthenol in HLMs.

Separation and determination of coumarins including furanocoumarins using micellar electrokinetic capillary chromatography

The conditions of micellar electrokinetic capillary chromatography for separation and simultaneous measurement of coumarins (coumarin, scoparone, isoscopoletin, esculin, esculetin, umbelliferone) including furanocoumarins (xanthotoxin, byakangelicin, isopimpinellin, bergapten, phellopterin, xanthotoxol) have been elaborated. The influence of different parameters, such as the pH of the buffer, sodium cholate (SC) or methanol concentration in the buffer, on the migration time, peak resolution, peak asymmetry, and number of theoretical plates was investigated. The optimum separation of the compounds was achieved using 50-µm i.d. capillaries with a total length of 64.5 cm (56 cm effective length) and a buffer system at pH 9.00 consisting of 50 mM sodium tetraborate, 45 mM SC, and 20% of methanol (v/v). The developed method ensured good repeatability of corrected peak areas and migration times (the relative standard deviations were in the range of 2.8-6.1% and 0.8-4.0%, respectively). The average limit of detection for all studied compounds was below 1.3 µg mL. Moreover, good linearity of the relationship between the peak corrected area and the concentration of the compounds was observed (correlation coefficient >0.99). The method was successfully applied in the quantitative analysis of two different types of samples, i.e. Heracleum sphondylium herb and Aesculus hippocastanum cortex.

A fast and accurate method for the pharmacokinetic research of four coumarin analogs in Fructus cnidii using capillary electro-chromatography with a methacrylate ester-based monolithic column

In the present study, a monolithic capillary column with higher permeability was developed for the in vivo discrimination of four coumarin analogs (bergapten, 2'-acetylangelicin, imperatorin, and osthole) that typically require long separation times in HPLC. Instead of conventional methacrylate ester monolith (containing 19.5% porogen) with insufficient permeability (K = 1.52 - 1.66 × 10^-14 M² ) for plasma sample, the proposed column (20.5% porogen) had better permeability (around 3.80 × 10^-14 M² ) while properties such as pore distribution, stability, and resolution changed slightly. As a result, due to the negatively charged electro-dynamic flow of the methacrylate ester groups in the monolith, the migration of targeted analytes was achieved within 6 min (compared with 30 min in HPLC) with acceptable resolution and improved sensitivity (0.005-0.02 μg/mL vs. 0.04 μg/mL). The proposed method was also applied to pharmacokinetic research: accelerated solvent extraction (ASE) was used to improve the extraction efficiency, which prepared extract much faster and more pure than conventional methods. As the pharmacokinetic parameters indicated, the monolithic capillary electro-chromatography method was efficient, sensitive, specific, and durable, guaranteeing its utility for the determination of multiple structure-related compounds in rat plasma.

Anti-inflammatory coumarins with short- and long-chain hydrophobic groups from roots of Angelica dahurica cv. Hangbaizhi

The (1)H NMR-guided fractionation of a cyclohexane soluble portion of the 75% ethanolic extract of the roots of Angelica dahurica cv. Hangbaizhi led to the isolation of two coumarins, namely, 5-(3"-hydroxy-3"-methylbutyl)-8-hydroxyfuranocoumarin, and isobyakangelicin hydrate-3"-ethyl ether, and ten coumarins with short- or long-chain hydrophobic groups, namely, andafocoumarins A-J. Their structures were elucidated by extensive spectroscopic analyses. The absolute configurations of the C-2" secondary alcohols in ten of these compounds were deduced via the circular dichroism data of the in situ formed [Rh2(OCOCF3)4] complex, and oxidation reactions were utilized to determine location of the double bonds in the lipid chain of andafocoumarins H and I, respectively. The long-chain hydrophobic group of andafocoumarin J was determined by the method of chemical degradation and GC-MS analysis. It was the first time that coumarins with short- or long-chain hydrophobic groups in this plant had been comprehensively investigated. All isolates were assayed for their inhibitory effect against nitric oxide (NO) production in a lipopolysaccharide (LPS)-activated RAW264.7 macrophage cell line, among which andafocoumarins A and B exhibited a potent inhibition on LPS-activated NO production with IC50 values of 19.7 and 13.9 μM, respectively, indicating their stronger inhibitory activity than l-N(6)-(1-iminoethyl)-lysine (IC50=23.7 μM), a selective inhibitor of inducible nitric oxide synthase.

Simultaneous determination of oleanolic acid, ursolic acid, quercetin and apigenin in Swertia mussotii Franch by capillary zone electrophoresis with running buffer modifier

The method of capillary zone electrophoresis (CZE) with direct UV detection was developed for the determination of oleanolic acid, ursolic acid, quercetin and apigenin. and then for the first time successfully applied to the analysis of four analytes in Swertia mussotii Franch and its preparations. Various factors affecting the CZE procedure were investigated and optimized, and the optimal conditions were: 50 × 10(-3) mol/L borate-phosphate buffer (pH 9.5) with 5.0 × 10(-3) mol/L β-cyclodextrin, 15 kV separation voltage, 20 °C column temperature, 250 nm detection wavelength and 5 s electrokinetic injection time (voltage 20 psi). Under the conditions, oleanolic acid, ursolic acid, quercetin and apigenin could be determined within the test ranges with a good correlation coefficient (r(2) > 0.9991). The limits of detection for conditions, oleanolic acid, ursolic acid, quercetin and apigenin were 0.3415, 0.2003, 0.0062 and 0.2538 µg/mL, respectively, and the intra- and inter-day relative standard deviations were no more than 4.72%. This procedure provided a convenient, sensitive and accurate method for simultaneous determination of oleanolic acid, ursolic acid, quercetin and apigenin in S. mussotii Franch.

Simultaneous Quantitative Determination of 12 Active Components in Yuanhu Zhitong Prescription by RP-HPLC Coupled with Photodiode Array Detection

Background:

Yuanhu Zhitong prescription (YZP) is a famous traditional Chinese medicine formula, which is officially recorded in Chinese Pharmacopoeia for the treatment of stomach pain, hypochondriac pain, headache and dysmenorrhea caused by qi-stagnancy and blood stasis. It is the first report for the simultaneous determination of 12 active components in YZP.

Objective:

A newly, simple, accurate and reliable method for the separation and determination of 12 active components (protopine, α-allocryptopine, coptisine, xanthotol, palmatine, dehydrocorydaline, glaucine, tetrahydropalmatine, tetrahydroberberine, imperatorin, corydaline, isoimperatorin) in YZP was developed and validated using HPLC-PAD.

Materials and Methods:

The analytes were performed on a Phenomenex Luna-C₁₈ (2) column (250×4.6 mm, 5.0 μm) with a gradient elution program using a mixture of acetonitrile and 0.1% phosphoric acid water solution (adjusted with triethylamine to pH 5.6) as mobile phase. Analytes were performed at 30°C with a flow rate of 1.0 mL/min.

Results:

The validated method was applied to analyze four major dosage forms of YZP coming from different manufacturers with good linearity (r², 0.9981~0.9999), precision (RSD, 0.24~2.89%), repeatability (RSD, 0.15~3.34%), stability (RSD, 0.14~3.35%), recovery (91.13~110.81%) of the 12 components.

Conclusion:

The proposed method enables the separation and determination of 12 active components in a single run for the quality control of YZP.

Simultaneous characterisation of fifty coumarins from the roots of Angelica dahurica by off-line two-dimensional high-performance liquid chromatography coupled with electrospray ionisation tandem mass spectrometry

INTRODUCTION

The root of Angelica dahurica is a traditional Chinese medicine that used for the treatment of headache, toothache, abscess, furunculosis and acne. Coumarins were the major bioactive constituents of A. dahurica, hence it is worthwhile developing a method to simultaneously characterise them, especially those in trace amounts.

OBJECTIVE

To develop an efficient method for the simultaneous characterisation of coumarins in A. dahurica.

METHODS

A method using off-line two-dimensional high-performance liquid chromatography coupled with electrospray tandem mass spectrometry (off-line 2D-HPLC-ESI/MS(n) ) was developed.

RESULTS

In total 50 coumarins, including 32 linear furanocoumarins, 16 bifuranocoumarins and two non-furanocoumarins, were identified from the roots of A. dahurica. The possible MS fragmentations of these coumarins are also proposed.

CONCLUSION

The method described here allows rapid and convenient identification of the coumarins in A. dahurica, and may be applied to other herbal medicines containing linear furanocoumarins.

A commonly used Chinese herbal formula, Shu-Jing-Hwo-Shiee-Tang, potentiates anticoagulant activity of warfarin in a rabbit model

Background: Drug interactions between traditional Chinese herbal medicines and the anticoagulant warfarin may cause patient harm and are, therefore, important in clinical practice. Our experience in daily practice suggests that prothrombin time (PT) is prolonged when warfarin is used in combination with the Chinese herbal formula Shu-Jing-Hwo-Shiee-Tang (SJHST) commonly used by patients with osteoarthritis. Objective: We conducted animal experiments to confirm the effect of SJHST and warfarin on anticoagulant activity. Methods: Forty-eight male New Zealand white rabbits were randomized into eight groups of six rabbits. Group A (Control group) was administered normal saline. Group B (Western Medicine group) was administered warfarin 1.5 mg/kg/day. Groups C, D, and E [Traditional Chinese Medicine (TCM) groups] were administered different doses of SJHST (0.5 mg/kg/day, 1 mg/kg/day, and 2 mg/kg/day, respectively). Groups F, G, and H (Combination Therapy groups) were administered warfarin 1.5 mg/kg/day and different doses of SJHST (0.5 mg/kg/day, 1 mg/kg/day, and 2 mg/kg/day, respectively). The total duration of treatment was 14 days. Blood samples were obtained prior to beginning the experiments (day 0) and on day 7, day 14, and day 17 (3 days after discontinuation of the medications). The activated partial thromboplastin time (APTT), PT, and thrombin time (TT) were calculated and compared among the different groups. Results: No significant changes were noted in APTT, PT or TT between the control and SJHST-only groups. Significant prolongations of APTT and PTT, but not TT, were observed in the combination groups compared to the warfarin-only group. The enhanced anticoagulant effects returned to normal three days after discontinuation of SJHST treatment. Conclusions: We confirmed that the Chinese herb SJHST enhances the anticoagulant effect of warfarin. Although the exact mechanisms of the interaction are unknown, physicians should be aware of the possibility of drug interactions between warfarin and Chinese herbal medicines owing to the increased risk of bleeding.

Identification and quantification of total coumarins from Urtica dentata Hand and its roles in promoting immune tolerance via TLR4-mediated dendritic cell immaturation

Urtica dentata Hand (UDH) is traditionally used in the Alpine region as a herbal medicine. Immunotherapy using total coumarins (TC) of UDH has been proposed, yet the cellular and molecular mechanisms remain incompletely characterized. Additionally, there is no method available for the quantification of the main coumarins in UDH. We describe maturation-resistant, TC-conditioned dendritic cell (DC), which expressed much lower MHC class II (I-Ak) and CD86, showed reduced capacity to stimulate effector T cell responses and upregulated PD-Ll (programmed death ligand-1). TC-DC-stimulated regulatory cells (Treg) were superior alloantigen-specific suppressor of the T effector response as compared to those stimulated by control (CTR)-DC. Furthermore, TC-conditioned DC increased the levels of Foxp3 and CTLA-4 in the CD25 T cell population. TC-DC downregulated toll like receptor 4 (TLR4) protein expression in response to LPS. This indicates that down-regulation of TLR4 in response to TC on DC is a critical signaling pathway that regulates the phenotype and function of DC. We also established a sensitive and specific high-performance liquid chromatography-diodearray detection-mass spectrometry (HPLC-DAD-MS) method for simultaneous identification of its main coumarins, 6,6',7,7'-tetramethoxyl-8,8'-biscoumarin (1), 7,7'-dihydroxy-6,6'-dimethoxy-8,8'-biscoumarin (2), 7,7'-dimethoxy-6,6'-biscoumarin (3), and scoparone (4). A demonstration of this mechanism and the method for identification and quantification of TC in UDH endorsed their potential as a tolerance-promoting herbal medicine to prevent or treat transplantation rejection and autoimmune diseases.

Development of a rapid resolution liquid chromatographic method combined with chemometrics for quality control of Angelicae dahuricae radix

INTRODUCTION

Angelicae dahuricae radix (Baizhi) is a widely used traditional Chinese medicine, for which the traditional processing method has been sun-drying after harvesting. In recent years this method has been replaced by sulphur-fumigation for the sake of improving its appearance and pest control. Correct identification of sulphur-fumigated Baizhi and rapid finding of appropriate chemical markers for the quality control of Baizhi are of very great importance.

OBJECTIVE

To develop a rapid and efficient method of rapid resolution liquid chromatography (RRLC) combined with chemometrics for discriminating sulphur-fumigated Baizhi and controlling its quality.

METHODOLOGY

The samples were separated on a Zorbax SB-C₁₈-column with a gradient elution programme using methanol and water. The optimal RRLC method was validated in terms of linearity, precision, stability and recovery test. In addition, hierarchical clustering analysis (HCA) and principle component analysis (PCA) were applied to differentiate the different samples.

RESULTS

All the constituents were well separated within 18 min. The results of chemical fingerprinting and quantitative analysis showed that the sulphur-fumigated method obviously destroyed the phytochemical profiles of Baizhi. Moreover, the sun-dried and sulphur-fumigated Baizhi could be clearly separated by HCA and PCA, and the critical markers such as oxypeucedanin and imperatorin accountable for such differences were ultimately screened out.

CONCLUSION

This study revealed that sulphur-fumigation is an inappropriate approach for processing crude drugs and should be prohibited, and that the proposed RRLC method combined with chemometrics demonstrated an efficient strategy for quality control of Baizhi.

An efficient strategy based on MAE, HPLC-DAD-ESI-MS/MS and 2D-prep-HPLC-DAD for the rapid extraction, separation, identification and purification of five active coumarin components from Radix Angelicae Dahuricae

INTRODUCTION

Further studies of active coumarin components in Radix Angelicae Dahuricae (AE) are absolutely essential to provide data on pharmacology, toxicology and quality for innovative drug candidates. Thus, the preparation of active component standards and the administration of coumarin monomers should be carried out. The isolation of the low-level active components from complex Traditional Chinese Medicine (TCM) samples necessitates the development of rapid, simple and economical modern extraction, separation, identification and purification methods.

OBJECTIVE

To develop an efficient strategy for the rapid extraction, separation, identification and purification of coumarins from AE.

METHODOLOGY

First, active coumarins in AE were extracted with microwave-assisted extraction (MAE) after the extraction conditions were optimised. Second, gradient extraction methods with MAE were used to partially purify AE. Third, a high-performance liquid chromatography-diode array detection-electrospray ionisation tandem mass spectrometry (HPLC-DAD-ESI-MS/MS) method was applied for the preliminary on-line identification and screening of the main coumarins in AE extract. Finally, a two-dimensional preparative high-performance liquid chromatography-diode array detection (2D-prep-HPLC-DAD) system was developed for further preparative separation of those target components.

RESULTS

Altogether 10 coumarins have been identified and five of them including xanthotoxol, osthenol, oxypeucedanin hydrate, byakangelicin and imperatorin were deemed as target components for the preparative isolation. All of the five isolated coumarins were at high purities of over 99% and the production rate was much higher than the traditional methods.

CONCLUSION

The present paper demonstrates that these consecutive approaches are very useful for to isolate chemical constituents from TCM.

CEC of phytochemical bioactive compounds

Although there are many publications related to technological or methodological developments of CEC, few focus on the analysis of natural products, especially phytochemical bioactive compounds. This review summarized the application of CEC in the analysis of phytochemical bioactive components, including flavonoids, nucleosides, steroids, lignans, quinones and coumarins, as well as fingerprint analysis of herbs. The strategies for optimization of CEC conditions and detection were also discussed.

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

Traditional Chinese medicines (TCMs) are gaining more and more attention all over the world, due to their specific theory and long historical clinical practice. But the uncontrollable quality is a bottleneck for its modernization and globalization. This paper reviewed the recent analytical methods in the quality control of TCMs, including screening strategies of bioactive markers from TCMs through biochromatographic methods, the traditional chromatographic methods, DNA methods, as well as the spectroscopic methods, including FT-IR, NIR and NMR. The comprehensive methods, such as fingerprint and multi-component quantification are emphasized; hyphenated techniques, like HPLC-MS, GC-MS, CE-MS, LC-NMR, chemometric methods, and combination of chemical and biological methods, such as biofingerprint, metabolic fingerprint are now more and more widely used in TCMs. In a few word, the analysis and quality control of TCMs are moving towards an integrative and comprehensive direction, in order to better address the inherent holistic nature of TCMs.

Separation and determination of coumarins in Fructus cnidii extracts by pressurized capillary electrochromatography using a packed column with a monolithic outlet frit

The pressurized capillary electrochromatography (pCEC) was utilized for the separation and determination of coumarins in Fructus cnidii extracts from 12 different regions. After a thorough study of analytical parameters such as acetonitrile content of the mobile phase, the concentration and pH of the buffer, and the applied voltage, a methodology was proposed to separate and determine six coumarins of F. cnidii extracts in less than 15 min. The experiments were performed in an in-house packed column with a monolithic outlet frit under the optimal conditions: pH 4.0 ammonium acetate buffer at 10 mM containing 50% acetonitrile at -6kV applied voltage. The calibration curves were linear in the range of 10.0-100.0 microg/mL for bergapten, 20.0-200.0 microg/mL for imperatorin, 5.0-400.0 microg/mL for osthole, 10.0-100.0 microg/mL for 2'-acetylangelicin, 10.0-200.0 microg/mL for oroselone, and 10.0-200.0 microg/mL for O-acetylcolumbianetin. The correlation coefficients were between 0.9967 and 0.9995. With this pCEC system, fingerprints of F. cnidii extracts were preliminarily established to distinguish three types of coumarins by characteristic peaks, and the quality of various sources of raw materials was evaluated by determining the contents of six coumarins.

Qualitative and quantitative analysis in quality control of traditional Chinese medicines

Separation techniques with high efficiency and sensitive detection have been widely used for quality control of traditional Chinese medicines (TCMs). High-performance liquid chromatography, gas chromatography, and capillary electrophoresis are commonly used to separate various components in TCMs. Ultraviolet detection, fluorescence detection, evaporative light-scattering detection, mass spectrometry and nuclear magnetic resonance can be applied to separation techniques for qualitative and quantitative analysis of TCMs. The development of quality control for TCMs based on quantitative and qualitative analysis from 2000 to 2007 are reviewed; the fingerprint technique is also discussed due to its broad application in the quality control of TCMs. Prospects for further research based on our primary results are also discussed.

Development of in-tube solid-phase microextraction coupled to pressure-assisted CEC and its application to the analysis of propranolol enantiomers in human urine

A successful hyphenation of in-tube solid-phase microextraction (SPME) and pressure-assisted CEC (pCEC) was developed by installing a poly(methacrylic acid-co-ethylene glycol dimethacrylate) monolithic capillary to the six-port valve in a CEC system. The device designed was appropriate for on-line in-tube SPME coupled to pCEC or muHPLC. The evaluation of this hyphenation was first carried out for in-tube SPME-muHPLC with analytical capillaries packed with 3 microm octadecyl silica (ODS). Theobromine (TB), theophylline (TP), and caffeine (CA) were chosen as model drugs for an easy comparison with the results obtained by in tube SPME-HPLC. The detection limits of these three analytes were improved more than 100 times when compared with the direct analysis by muHPLC. Then in-tube SPME-pCEC with CEC capillaries packed with perphenylcarbamoylated beta-CD-bonded silica particles was applied to the determination and analysis of propranolol enantiomers in human urine. Under optimal extraction and separation conditions, the experimental LODs were 4 and 7 ng/mL for (S)-propranolol and (R)-propranolol, respectively. The calibration curves showed good linearity for both (S)-propranolol (R(2) = 0.9997) and (R)-propranolol (R(2) = 0.9996) over the concentration range from 20 to 5000 ng/mL. Reproducibility of the method was also investigated with intra- and interday precisions lower than 10% for both enantiomers at different concentration levels.

Development of a quality evaluation method forFructus schisandraeby pressurized capillary electrochromatography

A pressurized CEC (pCEC) method with postcolumn detection cell had been developed for quantifying the lignans from Fructus schisandrae extracts. The effects of different experimental conditions, such as the ACN content of the mobile phase, the concentration and pH of the buffer, the applied voltage, and the supplementary pressure were studied. Five lignans (schisandrin, gomisin A, schisantherin C, deoxyschizandrin, schisandrin B) were baseline separated using a mobile phase of ACN-phosphate buffer (pH 5.4; 5 mM) (40:60 v/v) under -4 kV applied voltage. The method showed the satisfactory retention time and peak area repeatability. The calibration curves were linear in the range 50.0-1000.0 microg/mL for schisandrin, 20.0-500.0 microg/mL for gomisin A, 10.0-200.0 microg/mL for schisantherin C, 20.0-500.0 microg/mL for deoxyschizandrin, and 20.0-500.0 microg/mL for schisandrin B. The correlation coefficients were between 0.9978 and 0.9989. With this pCEC system, fingerprints of F. schisandrae were preliminarily established to distinguish two members S. chinensis (Turcz.) Baill. and S. sphenanthera Rehd. Et Wils. of F. schisandrae by characteristic peaks, and evaluate the quality of various sources of raw materials by determining the contents of the five lignans.

Multidimensional liquid chromatography system with an innovative solvent evaporation interface

An orthogonal two-dimensional liquid chromatographic (2D-LC) system was developed by using a vacuum-evaporation loop-type valve interface. Normal-phase liquid chromatography (NPLC) with a bonded CN phase column was used as the first dimension, and reversed-phase liquid chromatography (RPLC) with a C(18) column was used as the second dimension. All the solvents in the loop of the interface were evaporated at 90 degrees C under vacuum conditions, leaving the analytes on the inner wall of the loop. The mobile phase of the second dimension dissolved the analytes in the loop and injected them onto the secondary column, allowing an on-line solvent exchange of a selected fraction from the first dimension to the second dimension. The chromatographic resolution of analytes on the two dimensions was maintained at their optimal condition. Sample loss due to evaporation in the interface was observed that depended on the boiling point of the compound. Separation of sixteen polycyclic aromatic hydrocarbon mixtures and a traditional Chinese medicine Angelica dahurica was demonstrated.