Rapid determination of caffeoylquinic acid derivatives in Cynara scolymus L. by ultra‐fast liquid chromatography/tandem mass spectrometry based on a fused core C18 column

An ultra‐fast high‐performance LC‐ESI‐MS/MS method was developed for the analysis and quantification of caffeoylquinic acid derivatives, including chlorogenic acid, 1,3‐di‐O‐caffeoylquinic acid (cynarin) and 1,5‐di‐O‐caffeoylquinic acid, in artichoke (Cynara scolymus L.) heads and leaves. The rapid separation (less than 4 min) was achieved based on a Halo fused core C18‐silica column (50 mm×2.1 mm id, 2.7 μm). The target compounds were detected and quantified by a triple‐quadrupole mass spectrometer in multiple‐reaction monitoring mode. The calibration function is linear from 0.06 to 2800 ng/mL for chlorogenic acid, 0.3–3000 ng/mL for cynarin and 0.24–4800 ng/mL for 1,5‐di‐O‐caffeoylquinic acid, respectively. The average recoveries ranged from 92.1 to 113.2% with RSDs ≤6.5%. Moreover, four batches of artichoke head and leaf extracts were analyzed using the established method. The results indicated that the Halo fused core column provided much faster separations and higher sample throughput without sacrificing column ruggedness and reliability, and triple‐quadrupole MS provided extraordinarily lower LOQs for most of the target analytes. Comparing to conventional quantitative approaches, the established method was fast, sensitive and reliable for the determination of caffeoylquinic acid derivatives in artichoke.     

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.     

On‐Line Radical Scavenging Detection and Characterization of Antioxidants from Artemisia herba‐alba

Four caffeoylquinic acid (CQA) derivatives, 5‐O‐caffeoylquinic acid ( 1 ), 3,5‐di‐O‐caffeoylquinic acid ( 3 ), 4,5‐di‐O‐caffeoylquinic acid ( 4 ), and 3,4,5‐tri‐O‐caffeoylquinic acid ( 5 ), have been isolated from Artemisia herba‐alba growing wild in Algeria, using the on‐line HPLC? DAD? DPPH radical‐scavenging detection technique as guidance. In the course of the purification work, the non‐frequent (E)‐2‐(β‐D ‐glucopyranosyloxy)‐4‐methoxycinnamic acid ( 2 ) has also been isolated. The CQAs showed fair‐to‐good antioxidant activities determined by the DPPH^. scavenging assay. The structures of the five isolated compounds were determined by spectroscopic methods. The on‐line HPLC? DAD? DPPH technique allowed for a rapid pinpointing of antioxidants in the studied plant, accomplishing the facile guided isolation of the target molecules. Algerian A. herba‐alba could be an interesting source of natural antioxidants that deserve further work.     

Liquid chromatography coupled with ultraviolet absorbance detection,electrospray ionization,collision‐induced dissociation and tandem mass spectrometry on a triple quadrupole for the on‐line characterization of polyphenols and methylxanthines in green coffee beans

Liquid chromatography coupled with a photodiode array detector, electrospray ionization, collision‐induced dissociation and tandem mass spectrometry (LC‐DAD/ESI‐CID‐MS/MS) on a triple quadrupole (QqQ) has been used to detect and characterize polyphenols and methylxanthines in green coffee beans: three phenolic acids (caffeic acid, ferulic acid and dimethoxycinnamic acid), three isomeric caffeoylquinic acids (M_r 354), three feruloylquinic acids (M_r 368), one p‐coumaroylquinic acid (M_r 338), three dicaffeoylquinic acids (M_r 516), three feruloyl‐caffeoylquinic acids (M_r 530), four p‐coumaroyl‐caffeoylquinic acids (M_r 500), three diferuloylquinic acids (M_r 544), six dimethoxycinnamoyl‐caffeoylquinic acids (M_r 544), three dimethoxycinnamoyl‐feruloylquinic acids (M_r 558), six cinnamoyl‐amino acid conjugates, three cinnamoyl glycosides, and three methylxanthines (caffeine, theobromine and theophylline). Dimethoxycinnamic acid, three isomers of dimethoxycinnamoyl‐caffeoylquinic acids and another three of dimethoxycinnamoyl‐feruloylquinic acids, as well as the three cinnamoyl glycosides, had not previously been reported in coffee beans. Structures have been assigned on the basis of the complementary information obtained from UV‐visible spectra, relative hydrophobicity, scan mode MS spectra, and fragmentation patterns in MS² spectra (both in the positive and negative ion modes) obtained using a QqQ at different collision energies. A structure diagnosis scheme is provided for the identification of different isomers of polyphenols and methylxanthines. Copyright © 2009 John Wiley & Sons, Ltd.     

Authentication and quantitative analysis on the chemical profile of Xanthium fruit (Cang-Er-Zi) by high-performance liquid chromatography-diode-array detection tandem mass spectrometry method

A high-performance liquid chromatographic method using diode-array detection and electrospray ionization tandem mass spectrometry (HPLC-DAD-ESI-MS/MS) was developed for the qualitative and quantitative analysis on Xanthium fruit, a commonly used traditional Chinese medicine. In this study, 7 characteristic components, 1-O-caffeoylquinic acid, 4-O-caffeoylquinic acid, chlorogenic acid, 1,5-O-di-caffeoylquinic acid, 1,3-O-di-caffeoylquinic acid, 4,5-O-di-caffeoylquinic acid and 1,3,5-O-tri-caffeoylquinic acid were identified and quantified by a validated HPLC-DAD method, and a fingerprint comprised of 12 markers was established under the same operating conditions. Furthermore, HPLC-ESI-MS/MS method was successfully used to deduce the structure of three main constituents. On the basis of the established chromatographic profiles, 30 populations of cocklebur samples including 3 related species and 1 unknown species were divided into 3 chemotypes, indicated that place of origin significantly influences the kinds and content of components in cocklebur, and hence affects their quality. The simultaneous determination of 7 caffeoylquinic acids in the 30 samples showed a great variety in the amounts of caffeoylquinic acids present. The study indicated that some species such as Xanthium mongolicum of the genus Xanthium might be suitable for development as new alternative sources of caffeoylquinic acids to supplement the officially listed Xanthium species, and the abundant constituents such as chlorogenic acid perhaps should be recorded in some authorized publications and applied to the quality control or quality evaluation for Xanthium in China. The entire analytical procedure is reproducible and suitable for the authentication and quantification of Xanthium fruits.     

New Quinic Acid Derivatives from Hepatoprotective Inula crithmoides Root Extract

Fractionation directed by hepatoprotective activity of Inula crithmoides L. root resulted in the isolation of two new quinic acid derivatives, 3,5‐di‐O‐caffeoylquinic acid 1‐methyl ether ( I ; caffeoyl=(E)‐3‐(3,4‐dihydroxyphenyl)prop‐2‐enoyl; quinic acid=1,3,4,5‐tetrahydroxycyclohexanecarboxylic acid) and 4,5‐di‐O‐caffeoylquinic acid 1‐methyl ether ( II ), in addition to the well‐known hepatoprotective compound, 1,5‐di‐O‐caffeoylquinic acid ( III ). The hepatoprotective effect was indicated by the significant decrease in the level of four measured serum biochemical parameters (SGOT, SGPT, ALP, and bilirubin) in experimental rats. The structures of the isolated compounds were determined by analyses of 1D‐ and 2D‐NMR spectroscopic data.     

A rapid and sensitive UPLC‐MS/MS method for quantification of two caffeoylquinic acids and four main active components in rat plasma after an intravenous administration of Qingkailing injection and its application to a pharmacokinetic study

Qingkailing (QKL) injection, a modified modern Chinese medicine preparation, is widely used in the clinic for its significant antipyretic and anti‐inflammatory effects, but its serious adverse drug reactions have attracted more and more attention. Series of caffeoylquinic acids in QKL are widely suspected to be the allergens responsible for these adverse drug reactions. Therefore, pharmacokinetic studies of the caffeoylquinic acids are needed. In this paper, a simple, rapid and sensitive ultra‐performance liquid chromatography–tandem mass spectrometry method was developed for the simultaneous determination of chlorogenic acid, neochlorogenic acid, baicalin, geniposide, cholic acid and hyodeoxycholic acid in rat plasma. Chromatographic separation was achieved on a BEH C₁₈ column by a gradient elution at a flow rate of 0.40 mL/min in only 6.0 min. All analytes were monitored by multiple reaction monitoring mode with negative electrospray ionization. The calibration curves of these analytes were all linear (r > 0.9978) over wide concentration ranges. The intra‐ and inter‐ day precisions (relative standard deviations) were within 14.3% and accuracy (relative error) ranged from ?6.8 to 4.8%. The mean recoveries ranged from 74.5 to 105.6%. This validated method was successfully applied to the pharmacokinetic study of the six analytes in rats following an intravenous administration of QKL injection. Copyright © 2013 John Wiley & Sons, Ltd.     

Iridoid Glycosides and Phenolic Compounds from the Flowers of Vitex agnus‐castus

A new and rare type of iridoid glycoside, agnusoside ( 1 ), a new caffeoylquinic acid derivative, castusic acid ( 2 ), and a new sugar ester, 1,2‐di‐(4‐hydroxybenzoyl)‐β‐glucopyranose ( 3 ), along with ten known compounds belonging to iridoid glycosides (agnuside, trans‐eurostoside), caffeoylquinic acid derivatives (chlorogenic acid and isochlorogenic acid A), flavonoids (isoorientin, isovitexin, kaempferol 3‐O‐sophoroside, luteolin 6‐C‐(2′′‐O‐trans‐caffeoyl)glucopyranoside, and simple phenolic acids (4‐hydroxybenzoic acid, 3,4‐dihydroxybenzoic acid), chemical classes were isolated from the flowers of Vitex agnus‐castus. The structures of the isolates were established by extensive 1D‐ and 2D‐NMR spectroscopic analysis as well as HR‐ESI‐MS. Agnusoside ( 1 ) represents an unusual type of iridoid glycoside with its 6‐keto C(4) nonsubstituted aglycone.     

UHPLC–MS/MS quantification combined with chemometrics for the comparative analysis of different batches of raw and wine‐processed Dipsacus asper

A rapid and sensitive ultra‐high performance liquid chromatography with tandem mass spectrometry approach was established for the simultaneous determination of 4‐caffeoylquinic acid, loganic acid, chlorogenic acid, loganin, 3,5‐dicaffeoylquinic acid, dipsacoside B, asperosaponin VI, and sweroside in raw and wine‐processed Dipsacus asper . Chloramphenicol and glycyrrhetinic acid were employed as internal standards. The proposed approach was fully validated in terms of linearity, sensitivity, precision, repeatability as well as recovery. Intra‐ and interassay variability for all analytes were 2.8–4.9 and 1.7–4.8%, respectively. The standard addition method determined recovery rates for each analytes (96.8–104.6%). In addition, the developed approach was applied to 20 batches of raw and wine‐processed samples of Dipsacus asper . Principle component analysis and partial least squares‐discriminate analysis revealed a clear separation between the raw group and wine‐processed group. After wine‐processing, the contents of loganic acid, chlorogenic acid, dipsacoside B, and asperosaponin VI were upregulated, while the contents of 3,5‐dicaffeoylquinic acid, 4‐caffeoylquinic acid, loganin, and sweroside were downregulated. Our results demonstrated that ultra‐high performance liquid chromatography with tandem mass spectrometry quantification combined with chemometrics is a viable method for quality evaluation of the raw Dipsacus asper and its wine‐processed products.     

Identification of novel circulating coffee metabolites in human plasma by liquid chromatography-mass spectrometry

This study reports a liquid chromatography-mass spectrometry method for the detection of polyphenol-derived metabolites in human plasma without enzymatic treatment after coffee consumption. Separation of available standards was achieved by reversed-phase ultra performance liquid chromatography and detection was performed by high resolution mass spectrometry in negative electrospray ionization mode. This analytical method was then applied for the identification and relative quantification of circulating coffee metabolites. A total of 34 coffee metabolites (mainly reduced, sulfated and methylated forms of caffeic acid, coumaric acid, caffeoylquinic acid and caffeoylquinic acid lactone) were identified based on mass accuracy (<4 ppm for most metabolites), specific fragmentation pattern and co-chromatography (when standard available). Among them, 19 circulating coffee metabolites were identified for the first time in human plasma such as feruloylquinic acid lactone, sulfated and glucuronidated forms of feruloylquinic acid lactone and sulfated forms of coumaric acid. Phenolic acid derivatives such as dihydroferulic acid, dihydroferulic acid 4'-O-sulfate, caffeic acid 3'-O-sulfate, dimethoxycinnamic acid, dihydrocaffeic acid and coumaric acid O-sulfate appeared to be the main metabolites circulating in human plasma after coffee consumption. The described method is a sensitive and reliable approach for the identification of coffee metabolites in biological fluids. In future, this analytical method will give more confidence in compound identification to provide a more comprehensive assessment of coffee polyphenol bioavailability studies in humans.     

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.     

Characterization of procyanidin B2 oxidation products in an apple juice model solution and confirmation of their presence in apple juice by high-performance liquid chromatography coupled to electrospray ion trap mass spectrometry

Procyanidins (i.e. condensed tannins) are polyphenols commonly found in fruits. During juice and cider making, apple polyphenol oxidase catalyzes the oxidation of caffeoylquinic acid (CQA) into its corresponding o-quinone which further reacts with procyanidins and other polyphenols, leading to the formation of numerous oxidation products. However, the structure and the reaction pathways of these neoformed phenolic compounds are still largely unknown. Experiments were carried out on a model system to gain insights into the chemical processes occurring during the initial steps of fruit processing. Procyanidin B2 was oxidized by caffeoylquinic acid o-quinone (CQAoq) in an apple juice model solution. The reaction products were monitored using high performance liquid chromatography (HPLC) coupled to ultraviolet (UV)-visible and electrospray tandem mass spectrometry (ESI-MS/MS) in the negative mode. Oxidative conversion of procyanidin B2 ([M-H](-) at m/z 577) into procyanidin A2 at m/z 575 was unambiguously confirmed. In addition, several classes of products were characterized by their deprotonated molecules ([M-H](-)) and their MS/MS fragmentation patterns: hetero-dimers (m/z 929) and homo-dimers (m/z 1153 and 705) resulting from dimerization involving procyanidin and CQA molecules; intramolecular addition products at m/z 575, 573, 927, 1151 and 703. Interestingly, no extensive polymerization was observed. Analysis of a cider apple juice enabled comparison with the results obtained on a biosynthetic model solution. However, procyanidin A2 did not accumulate but seemed to be an intermediate in the formation of an end-product at m/z 573 for which two structural hypotheses are given. These structural modifications of native polyphenols as a consequence of oxidation probably have an impact on the organoleptic and nutritional properties of apple juices and other apple-derived foods.     

Characterisation by liquid chromatography coupled to electrospray ionisation ion trap mass spectrometry of phloroglucinol and 4-methylcatechol oxidation products to study the reactivity of epicatechin in an apple juice model system

The reactivity of the (-)-epicatechin structure towards caffeoylquinic acid o-quinones was studied in an apple juice model solution. The approach consisted in considering separately the reactivities of the two phenolic moieties of an (-)-epicatechin molecule: phloroglucinol and 4-methylcatechol were chosen to represent A- and B-rings, respectively. The oxidation products were characterised by RP-HPLC coupled with electrospray ionisation Mass spectrometry (MS). The reactivities of the A- and B-rings were clearly different on the basis of the oxidation products formed. Both A- and B-rings could be involved in covalent bond formation, but electron transfers only occurred with the B-ring. Most of the (-)-epicatechin oxidation products were linked by A/B-ring linkage ("head-to-tail" intermolecular coupling). After this first dimerisation step, intramolecular reactions seemed to be favoured. Therefore, the complexity of oxidation products in apple juice does not only result from an extensive polymerisation of native phenolic compounds, but also from a multiplicity of small molecules in different oxidation states and isomeric forms.     

Hydroethanolic Extract of Urtica dioica L. (Stinging Nettle) Leaves as Disaccharidase Inhibitor and Glucose Transport in Caco-2 Hinderer

Herbal treatment for diabetes mellitus is widely used. The pharmacological activity is thought to be due to the phenolic compounds found in the plant leaves. The present study aims to investigate the phytochemical composition of Urtica dioica (UD) hydroethanolic extract and to screen its antidiabetic activity by disaccharidase hindering and glucose transport in Caco-2 cells. The results have shown that a total of 13 phenolic compounds in this work, viz. caffeic and coumaric acid esters (1, 2, 4–7, 10), ferulic derivative (3), and flavonoid glycosides (8, 9, 11–13), were identified using HPLC-DAD-ESI/MS². The most abundant phenolic compounds were 8 (rutin) followed by 6 (caffeoylquinic acid III). Less predominant compounds were 4 (caffeoylquinic acid II) and 11 (kaempferol-O-rutinoside). The UD hydroethanolic extract showed 56%, 45%, and 28% (1.0 mg/mL) inhibition level for maltase, sucrase, and lactase, respectively. On the other hand, glucose transport was 1.48 times less at 1.0 mg/mL UD extract compared with the control containing no UD extract. The results confirmed that U. dioica is a potential antidiabetic herb having both anti-disaccharidase and glucose transport inhibitory properties, which explained the use of UD in traditional medicine.     

Quantitative Analysis of Caffeoylquinic Acids and Styrylpyrones in Sweetia panamensis Bark by UPLC

Six secondary metabolites from the methanolic extract of Sweetia panamensis (Fabaceae) bark were isolated and characterised. Along with the pyrones desmethylangonine β-d-O-glucopyranoside and desmethylangonine β-d-O-glucopyranosyl-(1→6)-O-β-d-glucopyranoside, already reported in this species, 5-O-caffeoylquinic acid (chlorogenic acid), 4-O-caffeoylquinic acid, 3-O-caffeoylquinic acid and the isoflavonoid 5-O-methylgenistein 7-O-β-d-glucopyranoside were isolated for the first time from S. panamensis. Additionally, an LC-ESI-MS qualitative analysis was performed and an ultra performance liquid chromatography (UPLC) method was developed and validated for the determination of these compounds. The UPLC method was applied to the quantitative analysis of plant samples. Pyrones and caffeoylquinic acids resulted to be the main compounds in the extract; in particular desmethylangonine β-d-O-glucopyranosyl-(1→6)-O-β-d-glucopyranoside was the most abundant compound.

     

Quantitative Analysis of Caffeoylquinic Acids and Styrylpyrones in Sweetia panamensis Bark by UPLC

Six secondary metabolites from the methanolic extract of Sweetia panamensis (Fabaceae) bark were isolated and characterised. Along with the pyrones desmethylangonine β-d-O-glucopyranoside and desmethylangonine β-d-O-glucopyranosyl-(1→6)-O-β-d-glucopyranoside, already reported in this species, 5-O-caffeoylquinic acid (chlorogenic acid), 4-O-caffeoylquinic acid, 3-O-caffeoylquinic acid and the isoflavonoid 5-O-methylgenistein 7-O-β-d-glucopyranoside were isolated for the first time from S. panamensis. Additionally, an LC-ESI-MS qualitative analysis was performed and an ultra performance liquid chromatography (UPLC) method was developed and validated for the determination of these compounds. The UPLC method was applied to the quantitative analysis of plant samples. Pyrones and caffeoylquinic acids resulted to be the main compounds in the extract; in particular desmethylangonine β-d-O-glucopyranosyl-(1→6)-O-β-d-glucopyranoside was the most abundant compound.     

Simultaneous Quantification of Seven Caffeoylquinic Acids in Ecotypes of Blumea balsamifera at Various Life Stages by High-Performance Liquid Chromatography

Blumea balsamifera is a traditional Chinese medicine containing various bioactive caffeoylquinic acids and usually used for the treatment of rheumatism, eczema, and dermatitis. An accurate and reliable high-performance liquid chromatography method was established for simultaneous determination of 5-O-caffeoylquinic acid, 3-O-caffeoylquinic acid, 4-O-caffeoylquinic acid, 1,3-di-O-caffeoylquinic acid, 3,4-di-O-caffeoylquinic acid, 3,5-di-O-caffeoylquinic acid, and 4,5-di-O-caffeoylquinic acid in B. balsamifera. The method was rigorously verified and was successfully applied to simultaneous quantification of seven caffeoylquinic acids in four ecotypes of B. balsamifera at five life stages. The results showed that the highest concentrations of seven compounds were present in September, October, and November, indicating that the optimal harvest time of B. balsamifera is in the autumn. Therefore, this method is suitable for the quantification of the seven compounds and quality control for B. balsamifera.     

An Insight into Kiwiberry Leaf Valorization: Phenolic Composition,Bioactivity and Health Benefits

During kiwiberry production, different by-products are generated, including leaves that are removed to increase the fruit’s solar exposure. The aim of this work was to extract bioactive compounds from kiwiberry leaf by employing microwave-assisted extraction (MAE). Compatible food solvents (water and ethanol) were employed. The alcoholic extract contained the highest phenolic and flavonoid contents (629.48 mg of gallic acid equivalents (GAE) per gram of plant material on dry weight (dw) (GAE/g dw) and 136.81 mg of catechin equivalents per gram of plant material on dw (CAE/g dw), respectively). Oppositely, the hydroalcoholic extract achieved the highest antioxidant activity and scavenging activity against reactive oxygen and nitrogen species (IC₅₀ = 29.10 μg/mL for O₂^•−, IC₅₀ = 1.87 μg/mL for HOCl and IC₅₀ = 1.18 μg/mL for ^•NO). The phenolic profile showed the presence of caffeoylquinic acids, proanthocyanidin, and quercetin in all samples. However, caffeoylquinic acids and quercetin were detected in higher amounts in the alcoholic extract, while proanthocyanidins were prevalent in the hydroalcoholic extract. No adverse effects were observed on Caco-2 viability, while the highest concentration (1000 µg/mL) of hydroalcoholic and alcoholic extracts conducted to a decrease of HT29-MTX viability. These results highlight the MAE potentialities to extract bioactive compounds from kiwiberry leaf.     

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).     

Profiling and characterisation by liquid chromatography/multi-stage mass spectrometry of the chlorogenic acids in Gardeniae Fructus

The chlorogenic acids of Gardeniae Fructus used traditionally as a Chinese herbal medicine (zhizi) have been investigated qualitatively by liquid chromatography/multi-stage mass spectrometry (LC/MS(4)). Twenty-nine chlorogenic acids were detected and twenty-five characterised to regioisomer level on the basis of their fragmentation, twenty-four for the first time from this source. Assignment to the level of individual regioisomers was possible for three caffeoylquinic acids, three dicaffeoylquinic acids, three sinapoylquinic acids, four caffeoyl-sinapoylquinic acids, two feruloyl-sinapoylquinic acids, one p-coumaroyl-sinapoylquinic acid, three (3-hydroxy, 3-methyl)glutaroylquinic acids, two (3-hydroxy, 3-methyl)glutaroyl-feruloylquinic acids, one (3-hydroxy, 3-methyl)glutaroyl-dicaffeoylquinic acid, and one (3-hydroxy, 3-methyl)glutaroyl-caffeoyl-feruloylquinic acid. Six (3-hydroxy, 3-methyl)glutaroyl-caffeoylquinic acids were detected and two were tentatively assigned as 3-caffeoyl-4-(3-hydroxy, 3-methyl)glutaroylquinic acid and 3-caffeoyl-5-(3-hydroxy, 3-methyl)glutaroylquinic acid. The (3-hydroxy, 3-methyl)glutaroyl residue modifies the mass spectral fragmentation behavior and elution sequence compared with the chlorogenic acids that contain only a cinnamic acid residue(s). Fourteen of these twenty-nine chlorogenic acids have not previously been reported from any source.