Simultaneous determination of iridoids, phenolic acids, flavonoids, and saponins in Flos Lonicerae and Flos Lonicerae Japonicae by HPLC-DAD-ELSD coupled with principal component analysis

A method, HPLC coupled with diode-array and evaporative light scattering detectors (HPLC-DAD-ELSD), was newly developed to evaluate the quality of Flos Lonicerae (FL) and Flos Lonicerae Japonicae (FLJ), through a simultaneous determination of multiple types of bioactive components. By employing DAD, the detection wavelengths were set at 240 nm for the determination of iridoids, 330 nm for phenolic acids, and 360 nm for flavonoids, respectively. While ELSD, connected in series after DAD, was applied to the determination of saponins. This assay was fully validated with respect to precision, repeatability, and accuracy. Moreover, principal component analysis (PCA) was used for the similarity evaluation of different samples, and it was proven straightforward and reliable to differentiate FL and FLJ samples from different origins. For PCA, two principal components have been extracted. Principal component 1 (PC1) influences the separation between different sample sets, capturing 54.598% variance, while principal component 2 (PC2) affects differentiation within sample sets, capturing 12.579% variance. In conclusion, simultaneous quantification of bioactive components by HPLC-DAD-ELSD coupled with PCA would be a well-acceptable strategy to differentiate the sources and to comprehensively control the quality of the medicinal plants FL and FLJ.     

Rapid and simple method for screening of natural antioxidants from Chinese herb Flos Lonicerae Japonicae by DPPH-HPLC-DAD-TOF/MS

A rapid and simple method has been developed for the screening and identification of natural antioxidants of Flos Lonicerae Japonicae (FLJ), derived from the flower buds of Lonicera japonica. The hypothesis is that upon reaction with 1,1-diphenyl-2-picrylhydrazyl (DPPH), the peak areas (PAs) of compounds with potential antioxidant effects in the HPLC chromatograms will be significantly reduced or disappeared, and the identity confirmation could be achieved by HPLC-DAD-TOF/MS hyphenated technique. Using the proposed approach, about 14 compounds in the FLJ extract were found to possess a potential antioxidant activity. They were identified as chlorogenic acid (1), 1-O-caffeoylquinic acid (1-O-CQA, 2), caffeic acid (4), 4-O-CQA (5), rutin (7), isoquercitrin (8), luteolin-7-O-glucoside (9), lonicerin (10), 4,5-O-dicaffeoylquinic acid (4,5-O-diCQA, 11), 3,5-O-diCQA (12), 1,3-O-diCQA (13), 3,4-O-diCQA (14), 1,4-O-diCQA (16), and luteolin (17). In addition, the free radical scavenging capacities of the available identified compounds were also investigated by HPLC assay. The results indicated that the compounds with PAs significantly decreasing were natural antioxidants, whereas those with PAs not changing presented no activities, which accordingly indicated that this newly proposed method could be widely applied for rapid screening and identification of natural antioxidants from complex matrices including Chinese herbal medicines.     

Binding study of Flos Lonicerae Japonicae with bovine serum albumin using centrifugal ultrafiltration and liquid chromatography

The screening and analysis of bioactive components in traditional Chinese medicines (TCMs) is very important not only for the quality control of Chinese herbs but also for elucidating the therapeutic principles. This study developed a new method for screening and analyzing bioactive compounds from TCMs using centrifugal ultrafiltration coupled with high-performance liquid chromatography. The method was successfully applied in the binding study of Flos Lonicerae Japonicae with bovine serum albumin (BSA), and 11 compounds were found to be bound with the BSA. Eight of them were positively identified as chlorogenic acid, caffeic acid, rutin, quercetin-3-O-glucoside, luteolin-7-O-glucoside, lonicerin, 3, 5-di-O-caffeoyl quinic acid and 3,4-di-O-caffeoyl quinic acid. Another three compounds were tentatively identified as two isomers of chlorogenic acid and one isomer of di-O-caffeoyl quinic acid by comparing the UV data and MS data with the previous reports. Based on modern pharmacological study, these compounds are the major bioactive components in Lonicera japonica. Therefore, the proposed method could be a good approach to predicting the potential bioactivities of multiple compounds in TCMs simultaneously.     

金银花的毛细管电泳指纹图谱研究

采用毛细管区带电泳法,以50 mmol/L硼砂(含20 mmol/L β-环糊精(CD),用磷酸调pH 8.0)为背景电解质,运行电压12 kV,紫外检测波长254 nm,重力进样15 s（高度8.5 cm）,建立了金银花药材水提取液的毛细管电泳指纹图谱(CEFP)。将13个不同产地的金银花药材供试液的CEFP进行比较,以电泳峰出现率100%计,确定金银花的共有指纹峰为18个。该CEFP具有较好的精密度和重现性,分离效能高且成本低廉。提出了指纹图谱宏观含量相似度R、投影含量相似度C和定量相似度P的概念,可从总体上评价药材化学组分的整体含量情况。从两个方面评价各产地药材与对照CEFP间的总体相似性,合格药材应具备以下两个条件：(1)代表化学成分分布相似性的定性相似度(S)≥0.90;(2)描述药材整体化学成分含量的定量相似度(R,C,P,Q)应在80%～120%。以此二类相似度指标控制金银花的质量,建立了指纹图谱评价的又一新方法。     

Screening and analysis of aconitum alkaloids and their metabolites in rat urine after oral administration of aconite roots extract using LC-TOFMS-based metabolomics

Aconite roots are popularly used in herbal medicines in China. Many cases of accidental and intentional intoxication with this plant have been reported; some of these are fatal because the toxicity of aconitum is very high. It is thus important to detect and identify aconitum alkaloids in biofluids. In this work, an improved method employing LC-TOFMS with multivariate data analysis was developed for screening and analysis of major aconitum alkaloids and their metabolites in rat urine following oral administration of aconite roots extract. Thirty-four signals highlighted by multivariate statistical analyses including 24 parent components and 10 metabolites were screened out and further identified by adjustment of the fragmentor voltage to produce structure-relevant fragment ions. It is helpful for studying aconite roots in toxicology, pharmacology and forensic medicine. This work also confirmed that the metabolomic approach provides effective tools for screening multiple absorbed and metabolic components of Chinese herbal medicines in vivo.     

基于超高效液相色谱联用高分辨质谱自动解析方法的金银花不同加工方式分析

金银花干燥加工方式直接影响其药用价值及经济效益。 采用基于超高效液相色谱联用静电场轨道阱高分辨质谱的非靶向代谢组学技术结合化学计量学自动化数据分析策略,分析了不同加工方式对金银花中化学成分的影响。金银花样品经甲醇-水（8∶2,体积比）溶液超声提取30 min,两次离心后取上清液,以Waters Acquity UPLC HSS T3色谱柱（2.1×100 mm, 1.8 μm）分离,乙腈-水溶液（均含有体积分数0.1%的甲酸）进行梯度洗脱。高分辨质谱选择正离子扫描模式（ESI+）并采用FULL MS/DD-MS2（TOP4）模式完成数据采集。在自动化解析方法软件平台对仪器采集的原始信号直接解析,鉴定出绿原酸、芦丁和异槲皮苜等16种差异性化合物。在化学成分解析的基础上,利用层次聚类分析和主成分分析等方法评价了晒干、阴干、电热烘干、烘房烘干、热泵烘干和真空冷冻干燥这6种加工方式获得的金银花样品品质差异。真空冷冻干燥、烘房烘干和热泵干燥等加工方式能够获得外观特征优质的金银花。在真空冷冻干燥方式下,金银花样品中的抗氧化功能性成分能够得到更好的保存。     

Qualitative and quantitative analysis of active flavonoids in Flos Lonicerae by capillary zone electrophoresis coupled with solid-phase extraction

Flavonoids are an important bioactive group in the commonly used herbal medicine Flos Lonicerae. A new method of capillary zone electrophoresis (CZE) coupled with solid-phase extraction (SPE) was developed for simultaneous assay of flavonoid aglycones and glycosides in Flos Lonicerae. Optimum CZE separation was achieved with a background electrolyte (BGE) solution consisting of 80 mM boric acid and 20 mM phosphate acid, adjusted to pH 8.1, with 15% acetonitrile (v/v) added, and applying a separation voltage of 28 kV. The SPE method was used for pretreating the complex matrix of botanical materials and good reproducibility was obtained when avicularin was used as internal standard. Linearity of the method was excellent with correlation coefficients (r2) in the range of 0.9995-0.9999 and detection limits were lower than 0.6 microg/mL for the four flavonoids. The obtained recoveries varied between 93 to 104% while the relative standard deviations (RSDs) were below 4.4% (n=3). The developed CZE method was successfully used for the separation of eight flavonoids and the quantification of the four flavonoids in five species of Flos Lonicerae.     

镧对金银花中重金属及药效成分含量的影响

以金银花为试材,研究了叶面喷施稀土镧对金银花中重金属及药效成分含量的影响。结果显示以过氧化物酶活性和叶绿素含量为指标,确定以30 mg·L-1的甘氨酸镧水溶液叶面喷施效果较好。30 mg·L-1的甘氨酸镧水溶液处理的金银花中,Cd,Cu和As含量与对照相比明显下降,同时药效成分绿原酸和木犀草苷的含量分别增加了9.14%和43.86%。与药典标准相比,重金属含量和药效成分含量都明显优于2010版药典标准。结果表明:适宜浓度稀土镧对金银花吸收重金属元素有抑制作用,并且能促进其药效成分的合成,进而提高金银花的品质。     

Bioanalytical challenges and strategies for accurately measuring acyl glucuronide metabolites in biological fluids

Bioanalysis of unstable compounds such as acyl glucuronide metabolites represents a great analytical challenge owing to poor analyte stability in biological matrices. The primary goal for bioanalytical assay development is to minimize the breakdown of acyl glucuronide metabolite into its parent aglycone during sample collection, transportation, storage and analysis. Samples need to be stabilized ex vivo immediately after sample collection to minimize potential breakdown and thus to ensure accurate concentration measurement of both acyl glucuronide metabolite and its parent aglycone. In this review paper, formation of acyl glucuronide metabolites, the importance of establishing acyl glucuronide exposure measurement and safety coverage, optimization of sample pretreatment to stabilize the acyl glucuronide metabolites, current analytical strategy of assaying them as well as considerations for regulatory filings are discussed. It is important to identify acyl glucuronide metabolites that are capable of undergoing hydrolysis and pH-dependent intra-molecular migration as well as covalently binding to plasma and tissue proteins which can cause toxicity in vivo in the early stages of drug development. Carefully planning analytical experiments, identifying structures of acyl glucuronides and monitoring their concentrations in early drug development can help assess the risks associated with their exposures and potentially predict their concentrations in human circulation.     

固相萃取/液相色谱-质谱/质谱法测定山银花中5种主要黄酮苷元的含量

该文通过含有盐酸的乙醇溶液回流水解并提取,HLB固相萃取柱净化,液相色谱-质谱/质谱法检测,建立了山银花中槲皮素、木犀草素、山萘酚、芹菜素和黄芩素5种黄酮苷元含量的测定方法。实验以芦丁、木犀草苷、紫云英苷、野漆树苷和黄芩苷5种黄酮苷为代表开展研究,山银花样品经50%的乙醇溶液(含10%浓盐酸)回流2 h水解黄酮苷,同时对黄酮苷元进行提取,HLB固相萃取柱净化,采用Mightysil RP-18色谱柱分离,液相色谱-质谱/质谱法检测(电喷雾离子源、多反应监测模式、负离子扫描),外标法定量测定水解后的5种黄酮苷元含量。方法的定量下限(S/N=10)为0.005 g/kg(槲皮素),0.01 g/kg(木犀草素和芹菜素)和0.05 g/kg(山萘酚和黄芩素)。在0~1.0 g/kg范围内,5种黄酮苷元的线性相关系数均大于0.995;在山银花样品中对待测物进行3种加标水平的回收实验(加标水平相当于水解后槲皮素和木犀草素含量为:0.10、0.20、0.40 g/kg,山萘酚、芹菜素和黄芩素含量为:0.05、0.10、0.20 g/kg),方法的平均回收率70.4%~104%;相对标准偏差为4.0%~12%。该方法实现了山银花中多种主要黄酮苷元含量的同时测定,且对研究山银花药效及与黄酮类化合物的关系具有重要意义。     

Integrating Anti-Influenza Virus Activity and Chemical Pattern Recognition to Explore the Quality Evaluation Method of Lonicerae Japonicae Flos

Lonicerae japonicae flos (LJF, Lonicera japonica Thunb.) is adopted as a core herb for preventing and treating influenza. However, the anti-influenza virus components of LJF and the impact of quality-affecting factors on the anti-influenza activity of LJF have not been systematically investigated. In this study, a strategy integrating anti-influenza virus activity, ultrahigh-performance liquid chromatography fingerprint and chemical pattern recognition was proposed for the efficacy and quality evaluation of LJF. As a result, six bioactive compounds were screened out and identified as neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid, 4,5-Di-O-caffeoylquinic acid, sweroside and secoxyloganin. Based on the bioactive compounds, chemical pattern recognition models of LJF were established by a linear discriminant analysis (LDA). The results of the LDA models and anti-influenza virus activity demonstrated that cultivation pattern significantly affected the anti-influenza effect of LJF and that the neuraminidase inhibition rate of wild LJF was significantly higher than that of cultivated LJF. Moreover, the quality of LJF samples with different processing methods and geographical origins showed no obvious difference. Overall, the proposed strategy in the current study revealed the anti-influenza virus components of LJF and provided a feasible method for thequality evaluation of LJF, which has great importance for assuring the clinical effect against influenza of LJF.     

LC-HRMS-based targeted metabolomics for high-throughput and quantitative analysis of 21 growth inhibition-related metabolites in Chinese hamster ovary cell fed-batch cultures

Chinese hamster ovary (CHO) cells have been widely used in the biopharmaceutical industry for production of therapeutic proteins. CHO cells in fed-batch cultures produce various amino acid–derived intermediate metabolites. These small molecule metabolic byproducts have proven to be critical to cell growth, culture performance, and, more interestingly, antibody drug productivity. Herein, we developed an LC-HRMS-based targeted metabolomics approach for comprehensive quantification of total 21 growth inhibition-related metabolites generated from 14 different amino acids in CHO cell fed-batch cultures. High throughput derivatization procedures, matrix-matched calibration curves, stable isotope-labeled internal standards, and accurate mass full MS scan were utilized to achieve our goal for a wide range of metabolite screening as well as validity and reliability of metabolite quantification. We further present a novel analytical strategy for extending the assay's dynamic range by utilizing naturally occurring isotope M + 1 ion as a quantification analog in the circumstances where the principal M ion is beyond its calibration range. The integrated method was qualified for selectivity, sensitivity, linearity, accuracy, precision, isotope analysis, and other analytical aspects to demonstrate assay robustness. We then applied this metabolomics approach to characterize metabolites of interest in a CHO cell-based monoclonal antibody (mAb) production process with fed-batch bioreactor culture mode. Absolute quantification combined with multivariate statistical analysis illustrated that our target analytes derived from amino acids, especially from branched-chain amino acids, closely correlated with cell viability and significantly differentiated cellular stages in production process.     

Screening and identification of metabolites of two kinds of main active ingredients and hepatotoxic pyrrolizidine alkaloids in rat after lavage Farfarae Flos extract by UHPLC‐Q‐TOF‐MS mass spectrometry

Farfarae Flos, the dried flower buds of Tussilago farfara L., is usually used to treat coughs, bronchitic and asthmatic conditions as an important traditional Chinese medicine. Tussilagone and methl butyric acid tussilagin ester are seen as representatives of two kinds of active substances. In addition, the pyrrolizidine alkaloids, mainly senkirkine and senecionine, present in the herb can be hepatoxic. In this study, a rapid and sensitive ultra‐high‐performance liquid chromatography coupled with hybrid triple quadrupole time‐of‐flight mass spectrometry method was successfully applied to identify the metabolites of tussilagone, methl butyric acid tussilagin ester, senkirkine and senecionine. A total of 35, 37, 18 and nine metabolites of tussilagone, methl butyric acid tussilagin ester, senkirkine and senecionine in rats were tentatively identified. Hydrolysis, oxidation, reduction and demethylation were the major metabolic reactions for tussilagone and methl butyric acid tussilagin ester. The main biotransformation routes of senkirkine and senecionine were identified as demethylation, N‐methylation, oxidation and reduction. This study is the first reported analysis and characterization of the metabolites and the proposed metabolic pathways might provide further understanding of the metabolic fate of the chemical constituents after oral administration of Farfarae Flos extract in vivo.     

Quantitative analysis of acetaminophen and its six metabolites in rat plasma using liquid chromatography/tandem mass spectrometry

Acetaminophen (APAP) is a widely used analgesic and antipyretic drug. It is mainly metabolized by phase 1 and 2 reactions in the liver, and thus it could be involved in many drug–drug interactions. Therefore, the study of APAP metabolism is important in toxicological and pharmacokinetic studies. The objective of this study was to develop a rapid and sensitive method for the determination of APAP and its six metabolites in rat plasma for the pharmacokinetic studies. APAP and its metabolites were separated through a Capcell Pak MGII C₁₈ column and quantitated with a 16 min run in a triple‐quadruple mass spectrometer. The mobile phases were composed of 0.1% formic acid in either 95% water or 95% acetonitrile and analysis was performed twice in positive and negative modes. Validations such as accuracy, precision, recovery, matrix effect and stability were found to be within acceptance criteria of validation guidelines, indicating that the assay was applicable to the determination of the plasma concentrations of drug and its six metabolites. In conclusion, we developed an LC‐MS/MS method for the quantitative analysis of APAP and its six metabolites in rat plasma, and this method appears to be useful for pharmacokinetic/toxicokinetic studies of APAP and its metabolites in rats. Copyright © 2012 John Wiley & Sons, Ltd.     

Uncovering the anticancer mechanism of petroleum extracts of Farfarae Flos against Lewis lung cancer by metabolomics and network pharmacology analysis

Lung cancer shows the highest incidence rate in the world. Thus, it has become increasingly important to find therapeutic drugs to treat lung cancer. Farfarae Flos (FF) has been used in traditional Chinese medicine to treat pulmonary diseases such as cough, bronchitis and asthmatic disorders. In this study, the anti-proliferation effects of petroleum extracts of FF (PEFF) on Lewis lung cancer cells and the corresponding mechanisms were studied using cell metabolomics. Fifteen differential metabolites in the cell extracts and the corresponding medium related to the anti-proliferation effect of PEFF were identified, which were probably involved in pyruvate metabolism and glycine, serine and threonine metabolism. For the cellular uptake compounds in PEFF, six metabolites derived from two prototype compounds were also tentatively identified by UHPLC-Q-Orbitrap high-resolution MS. Network pharmacology analysis demonstrated that the anti-proliferation mechanism of PEFF was also probably related to the target genes, including, Aurora-A, glutathione S-transferase Mu 1 (GSTM1), glutathione S-transferase P 1 (GSTP1), progesterone receptor and heme oxygenase-1 (HO-1), and further associated with the proteoglycans and PI3K/Akt signaling pathway. Cell metabolomics and network pharmacology analysis provided a holistic method to investigate the anti-proliferation mechanisms of PEFF. However, further studies were still needed to validate the potential target genes, pathways and active compounds in PEFF.     

Training in metabolomics research. I. Designing the experiment,collecting and extracting samples and generating metabolomics data

The study of metabolism has had a long history. Metabolomics, a systems biology discipline representing analysis of known and unknown pathways of metabolism, has grown tremendously over the past 20 years. Because of its comprehensive nature, metabolomics requires careful consideration of the question(s) being asked, the scale needed to answer the question(s), collection and storage of the sample specimens, methods for extraction of the metabolites from biological matrices, the analytical method(s) to be employed and the quality control of the analyses, how collected data are correlated, the statistical methods to determine metabolites undergoing significant change, putative identification of metabolites and the use of stable isotopes to aid in verifying metabolite identity and establishing pathway connections and fluxes. The National Institutes of Health Common Fund Metabolomics Program was established in 2012 to stimulate interest in the approaches and technologies of metabolomics. To deliver one of the program's goals, the University of Alabama at Birmingham has hosted an annual 4‐day short course in metabolomics for faculty, postdoctoral fellows and graduate students from national and international institutions. This paper is the first part of a summary of the training materials presented in the course to be used as a resource for all those embarking on metabolomics research. The complete set of training materials including slide sets and videos can be viewed at http://www.uab.edu/proteomics/metabolomics/workshop/workshop_june_2015.php . Copyright © 2016 John Wiley & Sons, Ltd.     

微波辅助萃取/高效液相色谱串联质谱法对山银花中活性成分含量的测定

建立了微波辅助萃取/高效液相色谱串联质谱法(MAE/HPLC-MS/MS)同时测定山银花中10种活性成分含量的方法。山银花药材采用MAE萃取,萃取溶剂为乙醇-水(7∶3),固液比1∶30,萃取温度70℃,萃取时间10 min。采用HPLC-MS/MS测定萃取液中活性成分的含量,色谱柱采用Agilent Poroshell120 SB-C18(100 mm×2.1 mm,2.7μm),以0.5%甲酸-乙腈为流动相进行梯度洗脱,负离子多重反应离子监测模式检测。在优化条件下,10种成分的定量分析在10 min内完成。结果表明,10种活性成分的线性范围为0.05～500 mg/L,相关系数(r)不低于0.996 9,检出限和定量下限分别在69～4 413μg/kg和231～14709μg/kg范围,回收率为94%～105%。采用该方法检测6个不同产地的山银花样品,10种活性成分的含量在3.98～14 356.31 mg/kg范围。该方法快速、准确,可有效地用于山银花药材的质量控制。     

Use of liquid chromatography hybrid triple‐quadrupole mass spectrometry for the detection of emodin metabolites in rat bile and urine

Emodin is the representative form of rhubarb, which is widely used in traditional Chinese medicine for the treatment of purgative, anti‐inflammatory, antioxidative and antiviral, etc. Previous reports demonstrated that emodin glucuronide was the major metabolite in plasma. Owing to the extensive conjugation reactions of polyphenols, the aim of this study was to identify the metabolites of emodin in rat bile and urine. Neutral loss and precursor ion scan methods of triple‐quadrupole mass spectrometer revealed 13 conjugated metabolites in rat bile and 22 metabolites in rat urine, which included four phase I and 18 phase II metabolites. The major metabolites in rat biosamples were emodin glucuronoconjugates. Moreover, rhein monoglucuronide, chrysophanol monoglucuronide and rhein sulfate were proposed for the first time after oral administration of emodin. Overall, liquid chromatography hybrid triple‐quadrupole mass spectrometry analysis leads to the discovery of several novel emodin metabolites in rat bile and urine and underscores that conjugated with glucuronic acid is the main metabolic pathway.     

LC/MS/MS analysis of the endogenous dimethyltryptamine hallucinogens,their precursors,and major metabolites in rat pineal gland microdialysate

We report a qualitative liquid chromatography–tandem mass spectrometry (LC/MS/MS) method for the simultaneous analysis of the three known N,N‐dimethyltryptamine endogenous hallucinogens, their precursors and metabolites, as well as melatonin and its metabolic precursors. The method was characterized using artificial cerebrospinal fluid (aCSF) as the matrix and was subsequently applied to the analysis of rat brain pineal gland‐aCSF microdialysate. The method describes the simultaneous analysis of 23 chemically diverse compounds plus a deuterated internal standard by direct injection, requiring no dilution or extraction of the samples. The results demonstrate that this is a simple, sensitive, specific and direct approach to the qualitative analysis of these compounds in this matrix. The protocol also employs stringent MS confirmatory criteria for the detection and confirmation of the compounds examined, including exact mass measurements. The excellent limits of detection and broad scope make it a valuable research tool for examining the endogenous hallucinogen pathways in the central nervous system. We report here, for the first time, the presence of N,N‐dimethyltryptamine in pineal gland microdialysate obtained from the rat. Copyright © 2013 John Wiley & Sons, Ltd.     

Metabolite profiling of ginsenosides in rat plasma,urine and feces by LC–MS/MS and its application to a pharmacokinetic study after oral administration of Panax ginseng extract

Panax ginseng is widely consumed as a functional food in the form of tea, powder, capsules, among others, and possesses a range of pharmacological activities including adaptogenic, immune‐modulatory, anti‐tumor, anti‐aging and anti‐inflammatory effects. The aim of this study was to identify and quantify the major ginsenosides and their metabolites in rat plasma, urine and feces after administration of P. ginseng extract using LC–MS/MS. We collected rat plasma samples at 0.5, 1, 2, 4, 8, 12, 24 and 48 h, and the amounts of urine and fecal samples accumulated in 24 h. Fourteen major ginsenosides and their metabolites were observed in fecal samples at high levels; however, low levels of 11 ginsenosides were detected in urine samples. The pharmacokinetics of the major ginsenosides and their metabolites was investigated in plasma. The results indicated that the maximum plasma concentration, time to maximum concentration and area under the curve of compound K were significantly greater than those of other ginsenosides. This study thus provides valuable information for drug development and clinical application of P. ginseng.