Chemical constituents of Meconopsis horridula and their simultaneous quantification by high‐performance liquid chromatography coupled with tandem mass spectrometry

Meconopsis horridula Hook.f. Thoms has been used as a traditional Tibetan medicine to clear away heat, relieve pain, and mobilize static blood. In this study, a reliable method based on high‐performance liquid chromatography with diode array detection and electrospray ionization quadrupole time‐of‐flight tandem mass spectrometry was established for the identification of components in this herb. A total of 40 compounds (including 17 flavonoids, 15 alkaloids, and eight phenylpropanoids) were identified or tentatively identified. Among them, 17 components were identified in the herb for the first time. Compound 39 appears to be a novel compound, which is confirmed as 3‐(kaempferol‐8‐yl)‐2,3‐epoxyflavanone by NMR spectroscopy and mass spectrometry. Moreover, seven major constituents were simultaneously quantified by the developed high‐performance liquid chromatography with tandem triple‐quadrupole mass spectrometry method. The quantitative method was validated and quality parameters were established. The study provides a comprehensive approach for understanding this herbal medicine.     

Qualitative and quantitative analysis of the major constituents in Jin‐Mu‐Gan‐Mao tablet by high‐performance liquid chromatography with diode‐array detection and quadrupole time‐of‐flight tandem mass spectrometry

Jin‐Mu‐Gan‐Mao tablet is a well‐known traditional Chinese medicinal preparation, which has been used to treat the common cold in China. In this study, a systematic method was established for the qualitative and quantitative analysis of the major constituents in Jin‐Mu‐Gan‐Mao tablet. First, a method of high‐performance liquid chromatography with diode‐array detection and quadrupole time‐of‐flight mass spectrometry was developed for identification of the multi‐constituents. Thirty‐one compounds including ten phenolic acids, 18 flavonoids, and three iridoid glycosides were clearly identified by comparison with the reference standards, and 11 compounds were deduced by comparison with the literature data. Second, a new quantitative analysis method of Jin‐Mu‐Gan‐Mao tablet was established by high‐performance liquid chromatography with diode‐array detection. Twelve compounds, either with high contents or strong bioactivities, were chosen as marker components. This analytical method was validated through intra‐ and interday precision, repeatability, and stability, with respective relative standard deviations less than 1.74, 2.54, 2.44, and 2.48%. The limits of detection and quantification were less than 0.327 and 0.881 μg/mL, respectively. The overall recoveries ranged from 97.04–102.76% (relative standard deviation ≤ 2.91%). Then this validated method was applied to determine ten batches of Jin‐Mu‐Gan‐Mao tablet. The results indicated that these new approaches can be applicable for the qualitative and quantitative analysis of Jin‐Mu‐Gan‐Mao tablet.     

Quality assessment of crude and processed ginger by high‐performance liquid chromatography with diode array detection and mass spectrometry combined with chemometrics

A sensitive, simple, and validated high‐performance liquid chromatography with diode array detection and mass spectrometry detection method was developed for three ginger‐based traditional Chinese herbal drugs, Zingiberis Rhizoma, Zingiberis Rhizome Preparatum, and Zingiberis Rhizome Carbonisata. Chemometrics methods, such as principal component analysis, hierarchical cluster analysis, and analysis of variance, were also employed in the data analysis. The results clearly revealed significant differences among Zingiberis Rhizoma, Zingiberis Rhizome Preparatum, and Zingiberis Rhizome Carbonisata, indicating variations in their chemical compositions during the processing, which may elucidate the relationship of the thermal treatment with the change of the constituents and interpret their different clinical uses. Furthermore, the sample consistency of Zingiberis Rhizoma, Zingiberis Rhizome Preparatum, and Zingiberis Rhizome Carbonisata can also be visualized by high‐performance liquid chromatography with diode array detection and mass spectrometry analysis followed by principal component analysis/hierarchical cluster analysis. The comprehensive strategy of liquid chromatography with mass spectrometry analysis coupled with chemometrics should be useful in quality assurance for ginger‐based herbal drugs and other herbal medicines.     

Differentiation of Mint (Mentha haplocalyx Briq.) from different regions in China using gas and liquid chromatography

In this study, complex substances such as Mint (Mentha haplocalyx Briq.) samples from different growing regions in China were analyzed for phenolic compounds by high‐performance liquid chromatography with diode array detection and for the volatile aroma compounds by gas chromatography with mass spectrometry. Chemometrics methods, e.g. principal component analysis, back‐propagation artificial neural networks, and partial least squares discriminant analysis, were applied to resolve complex chromatographic profiles of Mint samples. A total of 49 aroma components and 23 phenolic compounds were identified in 79 Mint samples. Principal component analysis score plots from gas chromatography with mass spectrometry and high‐performance liquid chromatography with diode array detection data sets showed a clear distinction among Mint from three different regions in China. Classification results showed that satisfactory performance of prediction ability for back‐propagation artificial neural networks and partial least squares discriminant analysis. The major compounds that contributed to the discrimination were chlorogenic acid, unknown 3, kaempherol 7‐O‐rutinoside, salvianolic acid L, hesperidin, diosmetin, unknown 6 and pebrellin in Mint according to regression coefficients of the partial least squares discriminant analysis model. This study indicated that the proposed strategy could provide a simple and rapid technique to distinguish clearly complex profiles from samples such as Mint.     

Isolation and purification of six iridoid glycosides from gardenia jasminoides fruit by medium‐pressure liquid chromatography combined with macroporous resin chromatography

Gardeniae fructus is one of the most frequently used herbs in traditional Chinese medicine. In the present study, a process for the enrichment of six iridoid glycosides from Gardeniae fructus was developed using medium‐pressure liquid chromatography combined with macroporous resin and reversed‐phase chromatography. The purities of different fractions from Gardeniae fructus were assessed using quantitative high‐performance liquid chromatography. After fractionation using HPD‐100 column chromatography, a 30% ethanol fraction was selected based on high‐performance liquid chromatography and liquid chromatography with mass spectrometry qualitative analysis to separate and purify. Based on the orientation analysis results, six compounds—deacetyl asperulosidic acid methyl ester, gardenoside, ixoroside, scandoside methyl ester, genipin‐1‐O‐β‐d‐ gentiobioside, and geniposide—were successfully isolated and purified in three to four combined steps from Gardeniae fructus. The purities of these compounds were found by high‐performance liquid chromatography analysis to be 97.9, 98.1, 95.5, 96.3, 97.1, and 98.7%, respectively. Moreover, their structures were elucidated by NMR spectroscopy and liquid chromatography with tandem mass spectrometry. The separation process was highly efficient, rapid, and accurate, making it a potential approach for the large‐scale production of iridoids in the laboratory and providing several marker compounds for quality control. This procedure may be meaningful for the purification of other natural products used in traditional Chinese medicine.     

High‐throughput LC–MS method for the rapid characterization of multiple chemical constituents and metabolites of Da‐Bu‐Yin‐Wan

Traditional Chinese medicine is the clinical experience accumulated by Chinese people against diseases. Da‐Bu‐Yin‐Wan is a famous traditional Chinese medicine formula consisting of Phellodendri amurensis Rupr., Anemarrhenae asphodeloides Bge., Radix Rehmanniae Preparata and Chinemys reevesii . In this study, ultra high performance liquid chromatography with electrospray ionization quadrupole time‐of‐flight high‐definition mass spectrometry with the control software of Masslynx (V4.1) was established for comprehensive screening and identification of the chemical constituents and serum metabolites of Da‐Bu‐Yin‐Wan in vivo and in vitro. Consequently, 70 peaks in the methanol extract from Da‐Bu‐Yin‐Wan and 38 peaks absorbed into rat blood were characterized. The 70 constituents in vitro included alkaloids, flavonoids, polysaccharide, limonoids, flavonoid, etc. And the 38 constituents consist of 22 absorbed prototypes and 16 metabolites of Da‐Bu‐Yin‐Wan absorbed in vivo. We fully clarified the chemical constituents of Da‐Bu‐Yin‐Wan and provided a scientific strategy for the screening and characterization of the chemical constituents and metabolites of traditional Chinese medicine in vitro and in vivo.     

Quality evaluation of moluodan concentrated pill using high‐performance liquid chromatography fingerprinting coupled with chemometrics

In this study, a fast and effective high‐performance liquid chromatography method was developed to obtain a fingerprint chromatogram and quantitative analysis simultaneously of four indexes including gallic acid, chlorogenic acid, albiflorin and paeoniflorin of the traditional Chinese medicine Moluodan Concentrated Pill. The method was performed by using a Waters X‐bridge C₁₈ reversed phase column on an Agilent 1200S high‐performance liquid chromatography system coupled with diode array detection. The mobile phase of the high‐performance liquid chromatography method was composed of 20 mmol/L phosphate solution and acetonitrile with a 1 mL/min eluent velocity, under a detection temperature of 30°C and a UV detection wavelength of 254 nm. After the methodology validation, 16 batches of Moluodan Concentrated Pill were analyzed by this high‐performance liquid chromatography method and both qualitative and quantitative evaluation results were achieved by similarity analysis, principal component analysis and hierarchical cluster analysis. The results of these three chemometrics were in good agreement and all indicated that batch 10 and batch 16 showed significant differences with the other 14 batches. This suggested that the developed high‐performance liquid chromatography method could be applied in the quality evaluation of Moluodan Concentrated Pill.     

Ultrafiltration‐LC–MS combined with semi‐preparative HPLC for the simultaneous screening and isolation of lactate dehydrogenase inhibitors from Belamcanda chinensis

Stroke represents the fourth leading cause of death in the USA and the second leading cause of death worldwide. Lactate dehydrogenase inhibitors are widely used in the treatment of ischemic stroke and natural products are considered a promising source of novel lactate dehydrogenase inhibitors. In this study, we used PC12 cells to determine the protective effect of extracts from the herb Belamcanda chinensis following toxic challenge. Using ultrafiltration high‐performance liquid chromatography coupled with photo‐diode array detection and electrospray ionization mass spectrometry, we screened and identified isoflavonoids from Belamcanda chinensis extracts. Semi‐preparative high‐performance liquid chromatography was then applied to separate and isolate the active constituents. Using these methods, we identified six major compounds in Belamcanda chinensis as lactate dehydrogenase inhibitors: tectoridin, iristectorin A, iridin, tectorigenin, irigenin, and irisflorentin, which were then isolated to >92% purity. This is the first report that Belamcanda chinensis extracts contain potent lactate dehydrogenase inhibitors. Our results demonstrate that the systematic isolation of bioactive components from Belamcanda chinensis guided by ultrafiltration high‐performance liquid chromatography coupled with photo‐diode array detection and electrospray ionization mass spectrometry represents a feasible and efficient technique that could be extended for the identification and isolation of other enzyme inhibitors.     

Classification of the medicinal plants of the genus Atractylodes using high‐performance liquid chromatography with diode array and tandem mass spectrometry detection combined with multivariate statistical analysis

Analytical methods using high‐performance liquid chromatography with diode array and tandem mass spectrometry detection were developed for the discrimination of the rhizomes of four Atractylodes medicinal plants: A. japonica, A. macrocephala, A. chinensis, and A. lancea. A quantitative study was performed, selecting five bioactive components, including atractylenolide I, II, III, eudesma‐4(14),7(11)‐dien‐8‐one and atractylodin, on twenty‐six Atractylodes samples of various origins. Sample extraction was optimized to sonication with 80% methanol for 40 min at room temperature. High‐performance liquid chromatography with diode array detection was established using a C₁₈ column with a water/acetonitrile gradient system at a flow rate of 1.0 mL/min, and the detection wavelength was set at 236 nm. Liquid chromatography with tandem mass spectrometry was applied to certify the reliability of the quantitative results. The developed methods were validated by ensuring specificity, linearity, limit of quantification, accuracy, precision, recovery, robustness, and stability. Results showed that cangzhu contained higher amounts of atractylenolide I and atractylodin than baizhu, and especially atractylodin contents showed the greatest variation between baizhu and cangzhu. Multivariate statistical analysis, such as principal component analysis and hierarchical cluster analysis, were also employed for further classification of the Atractylodes plants. The established method was suitable for quality control of the Atractylodes plants.     

Flexible and powerful strategy for qualitative and quantitative analysis of valepotriates in Valeriana jatamansi Jones using high‐performance liquid chromatography with linear ion trap Orbitrap mass spectrometry

Valeriana jatamansi Jones is an important medicinal plant and its quality is closely related to its region of origin. In the current study, we utilized a flexible and powerful strategy for comprehensive evaluation of the quality diversity for 15 regions in China. The method was based on a hybrid linear ion trap‐Orbitrap mass spectrometry platform. For structure characterization, fragmentation patterns were detected by analyzing a series of standard compounds using data dependent multistage mass spectrometry acquisition. A fragment ion database for valepotriates was established, and the acquired data were high throughput filtered by fragment ion search for compound identification. For quantitative purposes, we normalized the mass spectrometry data of 15 samples using SIEVE 2.0 and the differences in composition were analyzed using principal component analysis combined with hierarchical clustering analysis. The results identified a total of 92 compounds from Valeriana jatamansi Jones. Samples from Dali, Kunming, and Baoshan have better qualities and concentrations of the main active constituents. To verify our strategy, we compared the valtrate, acevaltrate, and baldrinal contents using high‐performance liquid chromatography with diode array detector. We developed and validated a comprehensive qualitative and quantitative analytical method to achieve quality control of Valeriana jatamansi Jones.     

Identification and quantitation of major phenolic compounds from penthorum chinense pursh. by HPLC with tandem mass spectrometry and HPLC with diode array detection

Penthorum chinense Pursh. is a traditional Chinese herbal medicine used for the treatment of various ailments specially related to liver. Gansu Granule, the medicine made from the extract of P. chinense, has been widely used in the clinical setting. But the information about its active ingredients is lacking. In this paper, the extract of P. chinense was analyzed by high performance liquid chromatography with electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry. Among the 27 compounds that were identified based on their mass spectrometry data, ten were reported for the first time from P. chinense. Chromatographic fingerprints generated by high‐performance liquid chromatography by analyzing 21 batches of P. chinense, displayed six common peaks. Finally, four major compounds were identified namely; gallic acid, brevifolin carboxylic acid, 2,6‐dihydroxyacetophenone‐4‐O‐β‐d‐ glucoside, and pinocembrin‐7‐O‐β‐d‐ glucoside. The average content of each compound was 24.58, 109.6, 15.52, and 18.81 mg/g, respectively. In addition, this study also suggests that the qualitative liquid chromatography with mass spectrometry and the quantitative high‐performance liquid chromatography analytical methods using monolithic columns are simple, rapid, accurate, and reproducible and have the potential to be used for the comprehensive quality control of P. chinense.     

Qualitative and quantitative analysis of chemical constituents in Ardisiae Japonicae Herba

Ardisiae Japonicae Herba is a well‐known traditional Chinese medicine for the treatment of bronchitis conjunctivitis, pneumonia, and trauma. In this work, a high‐performance liquid chromatography coupled with quadrupole time‐of‐flight mass spectrometry method was first established for the separation and structural identification of the chemical constituents in Ardisiae Japonicae Herba. A total of 15 compounds including coumarins, flavonoid glycosides, and catechins were identified or tentatively characterized based on their chromatographic behaviors and mass spectral fragmentation and by comparisons with the reference standards. Furthermore, a simple high‐performance liquid chromatography with diode array detection method was developed for the simultaneous determination of five major constituents. Results obtained from method validation, including linearity, precision, repeatability, stability, and recovery, showed that the established method was reliable and accurate. Bergenin and quercitrin were found to be the most abundant constituents and could be served as chemical markers for quality control of Ardisiae Japonicae Herba.     

Screening and analysis of potentially active components in Shenxiong glucose injection using UHPLC coupled with photodiode array detection and MS/MS

Shenxiong glucose injection, a pharmaceutical preparation containing a water extract of the roots of Salvia miltiorrhizae and ligustrazine hydrochloride, is widely used in clinical to treat cardiovascular diseases in China. The chemical components of the water extract have been reported and the cardioprotective effects of the injection have been evaluated. However, the chemical constituents of the injection and their correlations with its pharmacological effects have not been established. In this study, 13 chemical constituents of the injection have been identified or characterized by ultra‐high performance liquid chromatography with diode array detection and electrospray ionization quadrupole time‐of‐flight tandem mass spectrometry. Besides, the potentially active compounds of this preparation that directly act on cardiac cells have been screened by cell extraction and ultra high performance liquid chromatography targeted multiple reaction monitoring. As a result, eight potentially active compounds, danshensu ( 1 ), ligustrazine hydrochloride ( 4 ), salvianolic acid I/H ( 7 ), lithospermic acid ( 8 ), salvianolic acid D ( 9 ), rosmarinic acid ( 10 ), salvianolic acid B ( 12 ), and salvianolic acid C ( 13 ), were obtained and structurally characterized from the 11 target compounds used for screening. The liquid chromatography with quadrupole time‐of‐flight mass spectrometry and liquid chromatography with multiple reaction monitoring tandem mass spectrometry combination method has demonstrated its potency for the screening, detection, and structural identification of bioactive compounds in a complex matrix.     

Simultaneous determination of niacin and pyridoxine at trace levels by using diode array high‐performance liquid chromatography and liquid chromatography with quadrupole time‐of‐flight tandem mass spectrometry

A highly sensitive and simple diode‐array high‐performance liquid chromatography and liquid chromatography with quadrupole time‐of‐flight tandem mass spectrometry method was developed for the simultaneous determination of niacin and pyridoxine in pharmaceutical drugs, tap water, and wastewater samples. To determine the in vivo behavior of niacin and pyridoxine, analytes were subjected to simulated gastric conditions. The calibration plots of the diode‐array high‐performance liquid chromatography and liquid chromatography with quadrupole time‐of‐flight tandem mass spectrometry method showed good linearity over a wide concentration range with close to 1.0 correlation coefficients for both analytes. The limit of detection/limit of quantitation values for liquid chromatography quadrupole time‐of‐flight tandem mass spectrometry analysis were 1.98/6.59 and 1.3/4.4 μg/L for niacin and pyridoxine, respectively, while limit of detection/limit of quantitation values for niacin and pyridoxine in high‐performance liquid chromatography analysis were 3.7/12.3 and 5.7/18.9 μg/L, respectively. Recovery studies were also performed to show the applicability of the developed methods, and percentage recovery values were found to be 90–105% in tap water and 94–97% in wastewater for both analytes. The method was also successfully applied for the qualitative and quantitative determination of niacin and pyridoxine in drug samples.     

Screening and isolation of potential lactate dehydrogenase inhibitors from five Chinese medicinal herbs: Soybean,Radix pueraria,Flos pueraria,Rhizoma belamcandae,and Radix astragali

Stroke is among the leading causes of death and severe disability worldwide. Flavonoids have been extensively used in the treatment of ischemic stroke by reducing lactate dehydrogenase levels and thereby enhancing blood perfusion to the ischemic region. Here, we used ultrafiltration high‐performance liquid chromatography coupled with diode array detection and mass spectrometry for the rapid screening and identification of flavonoids from five Chinese medicinal herbs: soybean, Radix pueraria, Flos pueraria, Rhizoma belamcandae, and Radix astragali. Using PC12 cells as a suitable in vitro model of toxicity, cell viability was quantitated using the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay. The results showed that the extracts of soybean and the six major components, namely, acetyldaidzin, malonylgenistin, daidiain, glycitin, genistin, and acetylcitin; the extract of R. pueraria and its main component daidzein; the extract of F. pueraria and its three major components, tectorigenin, tectoridin, and tectorigenin‐7‐O‐xylosylglucosid; and the extract of R. belamcandae and its main component, tectoridin, were strong lactate dehydrogenase inhibitors. Also, the components of R. astragali showed no bioactivity. These findings indicate that the ultrafltration high‐performance liquid chromatography coupled with diode array detection and mass spectrometry method could be utilized in rapid screening and separation of bioactive compounds from a complex matrix.     

Rapid characterization of chemical constituents and metabolites of Qi‐Jing‐Sheng‐Bai granule by using UHPLC–Q‐TOF‐MS

Qi‐Jing‐Sheng‐Bai granule is an effective traditional Chinese medicine formula that has been widely used for the treatment of leukopenia post radiotherapy or chemotherapy. However, its chemical constituents were still unclear, which hindered interpreting bioactive constituents and studying integrative mechanisms. In this study, we developed a three‐step strategy to characterize the chemical constituents and metabolites of Qi‐Jing‐Sheng‐Bai by using ultra‐high performance liquid chromatography coupled with quadrupole time‐of‐flight mass spectrometry. As a result, a total of 143 compounds, including 56 flavonoids, 51 saponins, and 36 other compounds, of which contained six pairs of isomers, were tentatively identified and characterized via reference standards and by comparing mass spectrometry data with literature. After oral administration of 15 g/kg Qi‐Jing‐Sheng‐Bai, a number of 42 compounds including 24 prototype compounds and 18 metabolites have been detected in the serum of rats. This work serves as the first reference for Qi‐Jing‐Sheng‐Bai chemical components and metabolites. Moreover, it provided a rapid and valid analytical strategy for characterization of the chemical compounds and metabolites of traditional Chinese medicine formula.     

Novel strategy for quality consistency evaluation of Chinese medicine “YIQING” tablet that combines the simultaneous quantification and screening of ten bioactive constituents

The UV characteristics for different categories compounds in complex traditional Chinese medicines and herbal preparations usually vary. Thus, to achieve the integral analysis of multiwavelength fingerprint characteristics, we introduced a novel strategy of multiwavelength total fusion profiling. The simultaneous separation and quantification of multiple components by reversed‐phase high‐performance liquid chromatography coupled with diode array detection was developed in an effective, accurate, and reliable way. Furthermore, a 2,2‐diphenyl‐1‐picrylhydrazyl radical (DPPH) scavenging assay was set up to detect and screen the bioactivity of similar‐structure constituents (aloe‐emodin, rhein, emodin, chrysophanol, baicalein, wogonin, baicalin, wogonoside, berberine hydrochloride, and jatrorrhizine hydrochloride). Moreover, the high‐performance liquid chromatography DPPH assay was developed to monitor the relationship between the biological activity and the spatial structure, the number of hydroxyl groups, the concentration of the analytes in samples. The result of qualitative classification for 15 batches of “YIQING” tablets using principle component analysis was consistent with the quantitative fingerprint assessment using the average linear quantitative fingerprint method. Therefore, chemometrics, multiwavelength total fusion profiling in conjunction with average linear quantitative fingerprint method and antioxidant activity can control the quality of traditional Chinese medicines/herbal preparations comprehensively and practically.     

Characterization and simultaneous quantification of biological aporphine alkaloids in Litsea cubeba by HPLC with hybrid ion trap time‐of‐flight mass spectrometry and HPLC with diode array detection

The root and rhizome of Litsea cubeba (Lour) Pers., named ‘Dou‐chi‐jiang’ in Chinese, has been traditionally used for treatment of cardiovascular and cerebrovascular diseases, rheumatic arthralgia, and other diseases in China. Aporphine alkaloids are its characteristic ingredients and responsible for its bioactivities, especially anti‐inflammatory and analgesic effects. A sensitive and reliable high‐performance liquid chromatography with diode array detection‐tandem mass spectrometry method was developed for characterization and simultaneous determination of biological aporphine alkaloids in ‘Dou‐chi‐jiang’. The optimized chromatographic conditions were performed on an Eclipse XDB C₁₈ column with a gradient of acetonitrile/water containing 0.1% formic acid as the mass spectrometry mobile phase and acetonitrile/water containing 0.2% diethylamine (pH 3.10, adjusted by acetic acid) as the liquid chromatography mobile phase. The fragmentation pathways by loss of CO, ·CH₃, ·NH₃, and ·NH₂CH₃ were detected as characteristic for aporphine alkaloids. Based on these characteristics, total 12 analogues were identified. The quantification method was validated in terms of linearity, precision, and accuracy for six major aporphine alkaloids, which was successfully applied for simultaneous determination in ten batches of samples. The established method is simple, rapid, and specific for characterization and quantitation of aporphine alkaloids in ‘Dou‐chi‐jiang’ and other traditional Chinese medicines rich in this kind of ingredient.     

Fragmentation study of iridoid glycosides including epimers by liquid chromatography‐diode array detection/electrospray ionization mass spectrometry and its application in metabolic fingerprint analysis of Gardenia jasminoides Ellis

A high‐performance liquid chromatography‐diode array detection/electrospray ionization mass spectrometry (HPLC‐DAD/ESI‐MS) method was applied to the characterization of ten iridoid glycosides in Gardenia jasminoides Ellis, a traditional Chinese medicine. During the process of structural elucidation, two groups of isomers including two epimers were structurally characterized and differentiated according to their distinctive fragmentation patterns which were closely related to their isomeric differentiations. Subsequently, the major compounds were purified by multi‐dimensional chromatography and semi‐preparative HPLC and the structure identification was confirmed with NMR techniques. The major fragmentation pathways of iridoid glycosides in Gardenia jasminoides Ellis obtained through the MS data were schemed systematically, which provided the best sensitivity and specificity for characterization of the iridoid glycosides especially the isomers so far. Based on the fragmentation patterns of iridoid glycosides concluded, seven major iridoid glycosides were characterized in rat plasma after intravenous administration of Gardenia jasminoides Ellis. Copyright © 2010 John Wiley & Sons, Ltd.