Simultaneous quantitation of polygalaxanthone III and four ginsenosides by ultra‐fast liquid chromatography with tandem mass spectrometry in rat and beagle dog plasma after oral administration of Kai‐Xin‐San: Application to a comparative pharmacokinetic study

A fast, selective, and quantitative ultra‐fast liquid chromatography with tandem mass spectrometry method has been developed and validated for the simultaneous quantitation of polygalaxanthone III, ginsenoside Rb1, ginsenoside Rd, ginsenoside Re, and ginsenoside Rg1 in the plasma of rat and beagle dog after oral administration of Kai‐Xin‐San. After addition of the internal standard, salidroside, the plasma samples were extracted by liquid–liquid extraction and separated on a Venusil MP C₁₈ column with methanol/0.01% acetic acid water as mobile phase. The tandem mass spectrometric detection was performed in the multiple reaction monitoring with turbo ion spray source in a switching ionization mode. The method was examined, and found to be precise and accurate with the linearity range of the compounds. The intra‐ and interday precision and accuracy of the analytes were well within acceptance criteria (±15%). The mean extraction recoveries of analytes and internal standard were all >75.0%. The validated method has been successfully applied to comparing pharmacokinetic profiles of analytes in rat and beagle dog plasma. The results indicated that no significant differences were observed in pharmacokinetic parameters of ginsenoside Rg1, while the others had significant differences, which may due to the different mechanisms of absorption and metabolism.     

The effectiveness of borneol on pharmacokinetics changes of four ginsenosides in Shexiang Baoxin Pill in vivo

Shexiang Baoxin Pill (SBP) is a traditional Chinese medicine, widely used for cardiovascular diseases in the clinic. Ginsenosides are important effective components in SBP, but their pharmacokinetic characteristics are still not known. In this paper, we studied the pharmacokinetics of ginsenoside Rb1, Rc, Re and Rg1 in SBP and investigated the effect of borneol on the pharmacokinetic characteristic of ginsenosides based on an Agilent G6410A triple quadrupole LC/MS system. Results showed that the pharmacokinetic parameters of ginsenoside Rb1, Rc, Re and Rg1 in rat plasma after oral administration of SBP are significantly different with oral administration of SBP without Borneolum Syntheticum. Plasma pharmacokinetic profiles after oral administration of ginsenoside Rb1, Rc, Re, Rg1 and co‐administration with borneol at three different ratios (10:1, 1:1 and 1:10 ginsenoside vs borneol, w/w) were also determined. It was demonstrated that borneol can elevate the plasma concentration of ginsenosides after co‐admininstration. Copyright © 2013 John Wiley & Sons, Ltd.     

Comparative analysis on microbial and rat metabolism of ginsenoside Rb1 by high-performance liquid chromatography coupled with tandem mass spectrometry

Ginsenoside Rb1 is an active protopanaxadiol saponin from Panax species. In order to compare the similarities and differences of microbial and mammalian metabolisms of ginsenoside Rb1, the microbial transformation by Acremonium strictum and metabolism in rats were comparatively studied. Microbial transformation of ginsenoside Rb1 by Acremonium strictum AS 3.2058 resulted in the formation of eight metabolites. Ten metabolites (M1-M10) were detected from the in vivo study in rats and eight of them were identified as the same compounds as those obtained from microbial metabolism by liquid chromatography-tandem mass spectrometry analysis and comparison with reference standards obtained from microbial metabolism. Their structures were identified as ginsenoside Rd, gypenoside XVII, 20(S)-ginsenoside Rg3, 20(R)-ginsenoside Rg3, ginsenoside F2, compound K, 12beta-hydroxydammar-3-one-20(S)-O-beta-d-glucopyranoside, and 25-hydroxyl-(E)-20(22)-ene-ginsenoside Rg3, respectively. The structures of the additional two metabolites were tentatively characterized as 20(22),24-diene-ginsenoside Rg3 and 25-hydroxyginsenoside Rd by HPLC-MS/MS analysis. M7-M10 are the first four reported metabolites in vivo. The time course of rat metabolism of ginsenoside Rb1 was also investigated.     

Comparative pharmacokinetics of nine major bioactive components in normal and ulcerative colitis rats after oral administration of Lizhong decoction extracts by UPLC–TQ–MS/MS

Lizhong decoction (LZD), a classic formula, has been used to treat ulcerative colitis (UC) for thousands of years in clinical practice. However, the pharmacokinetic characteristics of its major bioactive components in rats under different physiological and pathological states are not clear. Thus, in this study, a rapid and sensitive analytical method, ultra‐performance liquid chromatography coupled with mass spectrometry (UPLC–MS/MS) method, was developed and applied to simultaneously determine glycyrrhizic acid, liquiritin, isoliquiritin, glycyrrhizin, isoliquiritigenin, 6‐gingerol, ginsenoside Rg1, ginsenoside Rb1 and ginsenoside Re in normal and UC rats after oral administration of LZD extract. A Waters BEH C₁₈ UPLC column was used for chromatographic separation, while acetonitrile and 0.1% formic acid were selected as mobile phase. The linearity of nine analytes was >0.9920. Inter‐ and intra‐day accuracy was ≤ 11.4% and precision was from 1.1 to 12.7%. Additionally, stable and suitable extraction recoveries were also obtained. The established method was validated and found to be specific, accurate and precise for nine analytes. Furthermore, it was successfully applied to the pharmacokinetic investigation of nine major components after oral administration of LZD extracts to normal and model rats, respectively. The results showed that the pharmacokinetic parameters (C_max, T_max, AUC_0–t, AUC_0–∞) in the plasma of UC rats were significantly different from those of normal rats, which could provide a reference for the clinical application of LZD.     

Qualitative and quantitative analysis of multiple components for quality control of Deng‐Zhan‐Sheng‐Mai capsules by ultra high performance liquid chromatography tandem mass spectrometry method coupled with chemometrics

Deng‐Zhan‐Sheng‐Mai capsules are a well‐known traditional Chinese patent medicine that was developed in China for the treatment of ischemic stroke. Its quality control focuses on Erigerontis Herba but ignores the contributions of Ginseng Radix et Rhizoma, Schisandrae Chinensis Fructus, and Ophiopogonis Radix. To improve the quality standards for this medicine, this work reports the application of a systematic ultra high performance liquid chromatography tandem mass spectrometric method coupled with chemometrics. Three qualitative and quantitative parameters are established for the evaluation of quality: chemical profiling, the relationship between the contents of 18 compounds and the antioxidant activity, and chemometric analysis. A total of 55 compounds, including 20 phenolic acids, 10 flavonoids, 15 saponins, and 10 lignans, were identified. The method for the quantitative determination of the aforementioned 18 compounds was validated. The limit of quantification ranged from 0.13 to 9.60 ng/mL. The overall recoveries ranged from 95.31 to 103.54%. Hierarchical cluster analysis and principal component analysis were applied to the data of 18 components in ten batches of samples. Nine compounds, including scutellarin, 3,5‐O‐dicaffeoylquinic acid, 4,5‐O‐dicaffeoylquinic acid, ginsenoside Rb1, ginsenoside Re, ginsenoside Rg1, ophiopogonin D, schisandrin, and schisandrol B, are suggested as chemical markers for evaluating the quality.     

A UFLC‐MS/MS method with a switching ionization mode for simultaneous quantitation of polygalaxanthone III,four ginsenosides and tumulosic acid in rat plasma: application to a comparative pharmacokinetic study in normal and Alzheimer's disease rats

A fast, sensitive and reliable ultra fast liquid chromatography‐tandem mass spectrometry (UFLC‐MS/MS) method has been developed and validated for simultaneous quantitation of polygalaxanthone III (POL), ginsenoside Rb1 (GRb1), ginsenoside Rd (GRd), ginsenoside Re (GRe), ginsenoside Rg1 (GRg1) and tumulosic acid (TUM) in rat plasma after oral administration of Kai‐Xin‐San, which plays an important role for the treatment of Alzheimer's disease (AD). The plasma samples were extracted by liquid–liquid extraction using ethyl acetate–isopropanol (1:1, v/v) with salidrdoside as internal standard (IS). Good chromatographic separation was achieved using gradient elution with the mobile phase consisting of methanol and 0.01% acetic acid in water. The tandem mass spectrometric detection was performed in multiple reaction monitoring mode on 4000Q UFLC‐MS/MS system with turbo ion spray source in a negative and positive switching ionization mode. The lower limits of quantification were 0.2–1.5 ng/ml for all the analytes. Both intra‐day and inter‐day precision and accuracy of analytes were well within acceptance criteria (±15%). The mean absolute extraction recoveries of analytes and IS from rat plasma were all more than 60.0%. The validated method has been successfully applied to comparing pharmacokinetic profiles of analytes in normal and AD rat plasma. The results indicated that no significant differences in pharmacokinetic parameters of GRe, GRg1 and TUM were observed between the two groups, while the absorption of POL and GRd in AD group were significantly higher than those in normal group; moreover, the GRb1 absorbed more rapidly in model group. The different characters of pharmacokinetics might be caused by pharmacological effects of the analytes. Copyright © 2013 John Wiley & Sons, Ltd.     

Comparative pharmacokinetics of the main active components in normal and ulcerative colitis rats after oral administration of Zingiberis Rhizoma–Ginseng Radix et Rhizoma herb pair and its single herb extracts by LC–MS/MS

Zingiberis Rhizoma and Ginseng Radix et Rhizoma are usually used together for the treatment of ulcerative colitis in clinical practices. However, their compatibility mechanism remains unclear. In this study, a rapid and sensitive liquid chromatography with tandem mass spectrometry method was developed for simultaneous quantification of ginsenoside Re, ginsenoside Rg1, ginsenoside Rb1, and 6-gingerol in rat plasma after oral administration of Zingiberis Rhizoma–Ginseng Radix et Rhizoma herb pair and its single herb extracts. The calibration curves exhibited good linearity, with correlation coefficients of more than 0.993. The precision deviations of intra- and interday analysis were within 10.66%, and accuracy error ranged from −12.74 to 11.56%. The average recoveries of analytes were higher than 76.60% and the matrix effects were minimal. Thus, the validated method was successfully applied to a pharmacokinetic study of four ingredients in normal and ulcerative colitis rat plasma. The results indicated that the pharmacokinetic parameters of four analytes in normal and model groups showed significant differences. The larger exposure (the mean AUC_0-t of ginsenoside Re, ginsenoside Rg1, ginsenoside Rb1, and 6-gingerol were increased by 50.93, 141.90, 3.68, and 37.25%, respectively) and slower elimination (the CLz/F of ginsenoside Re, ginsenoside Rg1, and 6-gingerol were decreased by 52.94, 83.64, and 32.18%, respectively) were observed in ulcerative colitis rats. Furthermore, compared with single herbs, the analytes in rat plasma after oral administration of combined extracts presented relatively high systemic exposure levels with AUC_0-t > 2000 h·ng/mL and C_max > 200 ng/mL. Collectively, the differences of pharmacokinetic characteristics revealed the synergistic effect of Zingiberis Rhizoma–Ginseng Radix et Rhizoma herb pair, which provided a valuable and reliable basis for its clinical application in the treatment of ulcerative colitis.     

Determination of Seven Major Ginsenosides in Different Parts of Panax quinquefolius L.(American Ginseng) with Different Ages

Ginsenosides Rg1,Re,Rb1,Rc,Rb2,Rb3,and Rd in different parts of the American ginseng plant were investigated.The extraction process was a pressurized microwave-assisted extraction(PMAE).The seven ginsenosides were separated and determined by high-performance liquid chromatography(HPLC) with a ultraviolet(UV) detector,at 203 nm.The experiment results showed significant variations in the individual ginsenoside contents of the American ginseng in different parts and ages of the plant.The results demonstrated that the leaves,root hairs,and rhizomes of Panax quinquefolius L.contained higher ginsenoside contents,followed by the main roots and stems.The leaves contained dramatically higher levels of ginsenoside Rg1,Rb3,and Rd than the other four parts.Higher contents of Rb1 and Re were present in the main roots,root hairs,and rhizomes.The amount of ginsenoside content in the stems was the lowest.The total content of the seven ginsenosides in main roots,root hairs and rhizomes increased with the age of the plant.In contrast,the ginsenoside contents in the leaves and stems decreased with a year of growth.     

Simultaneous determination of panax notoginsenoside R1, ginsenoside Rg1, Rd, Re and Rb1 in rat plasma by HPLC/ESI/MS: platform for the pharmacokinetic evaluation of total panax notoginsenoside, a typical kind of multiple constituent traditional Chinese medicine

A platform for the pharmacokinetic study of multiple constituent traditional Chinese medicine was developed and validated. An HPLC/ESI/MS method was employed for the simultaneous determination of panax notoginsenoside R1, ginsenoside Rg1, Rd, Re and Rb1 in rat plasma. After the addition of digoxin as an internal standard (IS), rat plasmas were extracted with n-butanol saturated with pure water and all analytes were separated on a reversed-phased C(18) column with a mobile phase of acetonitrile-water (0.5 mM ammonium chloride) and pumped at a flow rate of 0.2 mL/min. Analytes were determined in a single quadrupole mass spectrometer using an electrospray ionization source. HPLC/ESI/MS was performed in the selected-ion monitoring mode with the chlorinated adducts of molecular ions [M + Cl]( -) at m/z 967.75, 835.80, 981.80, 981.80, 1143.65 and 815.40 for R1, Rg1, Rd, Re, Rb1 and digoxin, respectively. The method showed excellent linearity over the concentration range 3.03-775.00 ng/mL (r(2) = 0.9994) for R1, 4.00-1025.00 ng/mL (r(2) = 0.9991, 0.9988, 0.9991) for Rg1, Rd and Re, respectively, and 2.77-710.00 ng/mL for Rb1 (r(2) = 0.9990). The low limit of quantification was 3.03, 4.00, 4.00, 4.00 and 2.77 ng/mL for R1, Rg1, Rd, Re and Rb1, respectively, with S/N > 10. The intra- and inter-day precisions were below 12.00% and the accuracy was between -2.31 and +4.43% for all analytes. The extract recoveries of analytes were from 67.47 to 94.18%. All analytes were stable in rat plasma after storage for 12 h at ambient temperature, at 4 degrees C for 12 h in the sample pool, at -20 degrees C for 4 weeks and at -20 degrees C for three thaw-freeze cycles. The HPLC/ESI/MS technique provided an excellent method for the simultaneous quantification of R1, Rg1, Rd, Re and Rb1 in rat plasma and was successfully applied to the pharmacokinetic study of a multiple-constituent traditional Chinese medicine, total panax notoginsenoside (Xuesaitong injection).     

Simultaneous determination of tanshinol,protocatechuic aldehyde,protocatechuic acid,notoginsenoside R1, ginsenoside Rg1 and Rb1 in rat plasma by LC–MS/MS and its application

Dantonic pill, consisting of Salviae miltiorrhize , Panax notoginseng and Borneol , is a widely used compound Chinese medicine for preventing and treating ischemic cardiovascular diseases in China. In the present study, an original and sensitive method for simultaneous determination of tanshinol (i.e. danshensu), protocatechuic aldehyde, protocatechuic acid, notoginsenoside R1, ginsenoside Rg1 and Rb1 in rat plasma by liquid chromatography–tandem mass spectrometry operated in positive/negative ion switching mode was established and validated. The lower limits of quantification for tanshinol, protocatechuic aldehyde, protocatechuic acid, notoginsenoside R1, ginsenoside Rg1 and Rb1 were 5, 0.5, 1, 0.5, 0.5 and 2 ng/mL, respectively. All of the calibration curves showed good linearity over the investigated concentration range (r > 0.99). Validation results demonstrated that the above compounds were accurately, precisely and robustly quantified in rat plasma. The method was successfully applied to characterize the pharmacokinetic profiles of all six compounds in rats following a single oral administration of Dantonic pill.     

Plasma pharmacochemistry combined with pharmacokinetics and pattern recognition analysis to screen potentially bioactive components from Daming capsule using ultra high performance liquid chromatography with electrospray ionization quadrupole time‐of‐flight mass spectrometry

Daming capsule is a traditional Chinese medicine for hyperlipidemia treatment. However, the vague understanding of the bioactive components of Daming capsule hampers its modernization and internationalization. This work first developed a high‐throughput, high‐resolution, and high‐sensitivity ultra high performance liquid chromatography with electrospray ionization quadrupole time‐of‐flight tandem mass spectrometry method for identifying the absorbed compounds and monitoring the pharmacokinetics of Daming capsule. A high‐throughput strategy integrating plasma pharmacochemistry, pharmacokinetics, and pattern recognition analysis was also established for screening the bioactive components of Daming capsule in vivo. The established strategy based on ultra high performance liquid chromatography with electrospray ionization quadrupole time‐of‐flight tandem mass spectrometry was successfully applied to screen the bioactive components of Daming capsule. Up to 53 absorbed compounds were identified. Six anthraquinones with fast and high absorption, namely, emodin‐O‐glucoside, aurantio‐obtusin, aloe‐emodin, rhein, emodin, and chrysophanol, were screened as potentially bioactive components of Daming capsule. The plasma pharmacochemistry and pharmacokinetics of Daming capsule were reported for the first time. Notably, the high‐throughput and reliable strategy facilitated the screening and identification of bioactive components of traditional Chinese medicine, thereby providing novel insights into the research and development of new drugs.     

Complete assignment of 1H and 13C NMR data for nine protopanaxatriol glycosides

Nine protopanaxatriol glycosides isolated from mild acid hydrolysis products of crude root saponins of Panax notoginseng were identified as 20(R)‐ginsenoside‐Rh1, 20(S)‐ginsenoside‐Rh1, ginsenoside‐Rg1, ‐Re and ‐Rg2, notoginsenoside‐R2 and ‐R1, a mixture of 25‐hydroxy‐20(S)‐ginsenoside‐Rh1 and its C‐20 (R) epimer, ginsenoside‐Rh4. The complete assignments of the ¹H and ¹³C NMR chemical shifts for these glycosides were obtained by means of 2D NMR techniques, including ¹H–¹H COSY, ROESY, HMQC, HMBC and HMQC‐TOCSY spectra. The glycosylation shift effect of protopanaxatriol and the differences in chemical shifts between 20(R)‐ and 20(S)‐protopanaxatriol isomers are also discussed. Except for ginsenoside‐Re and ‐Rg2, complete NMR assignments of the other seven glycosides are reported for the first time. Copyright © 2002 John Wiley & Sons, Ltd.     

Ultra‐fast liquid chromatography with tandem mass spectrometry determination of eight bioactive components of Kai‐Xin‐San in rat plasma and its application to a comparative pharmacokinetic study in normal and Alzheimer's disease rats

A method of ultra‐fast liquid chromatography with tandem mass spectrometry was developed and validated for the simultaneous quantitation of eight bioactive components, including polygalaxanthone III, sibiricaxanthone B, tenuifolin, sibiricose A5, sibiricose A6, tenuifoliside A, ginsenoside Re and ginsenoside Rb1 in rat plasma after oral administration of Kai‐Xin‐San. The plasma samples were extracted by liquid–liquid extraction using digoxin as an internal standard. Chromatographic separation was performed on a Venusil MP C₁₈ column (100 mm × 2.1 mm, 3 μm) with methanol and 0.05% acetic acid in water as mobile phase. The tandem mass spectrometric detection was performed in the multiple reaction monitoring with turbo ion spray source in the negative ionization. Validation parameters were within acceptable ranges. The established method has been successfully applied to compare the pharmacokinetic profiles of the analytes between normal and Alzheimer's disease rats. The results indicated that there were significant differences in pharmacokinetic parameters of some components between two groups, which may be due to the mechanisms of Alzheimer's disease and pharmacological effects of the analytes. The pharmacokinetic research in the pathological state might provide more useful information to guide the clinical usage of herbal medicine.     

Simultaneous determination of ginsenoside Rb1, ginsenoside Rg1, paeoniflorin,albiflorin and oxypaeoniflorin in rat plasma by liquid chromatography–tandem mass spectrometry: Application to a pharmacokinetic study of wen‐Yang‐Huo‐Xue soft capsule

A simple and sensitive HPLC–MS/MS method was developed and fully validated for simultaneous determination of ginsenoside Rb1, ginsenoside Rg1, paeoniflorin, albiflorin and oxypaeoniflorin in rat plasma. Plasma samples were pretreated with protein precipitation using acetonitrile. The chromatographic separation was carried out on a C₁₈ column with a gradient mobile phase consisting of acetonitrile and water (containing 0.1% formic acid). All analytes and digoxin (internal stand, IS) were quantitated through electrospray ionization in negative ion multiple reaction monitoring mode. All calibration curves exhibited good linearity (r > 0.9960) over a wide concentration range for all components. The intra‐day and inter‐day precisions (RSD) at three different levels were all <12.0% and the accuracies (RE) ranging from −6.1 to 6.2%. The extraction recoveries of the five compounds ranged from 89.2 to 97.1%. The validated method was successfully applied in a comparative pharmacokinetic study of Wen‐Yang‐Huo‐Xue soft capsule (WYHXSC) in rats. Compared with single pure component, the exposure of the investigated components, except for oxypaeoniflorin, increased after oral administration of WYHXSC in rats, which suggested a synergistic effects between the herbs in the WYHXSC preparations.     

New triterpenoid saponins from fruits specimens of Panax japonicus collected in Kumamoto and Miyazaki prefectures (1)

Seven new dammarane-type triterpenoid saponins, chikusetsusaponin FK1 (1), chikusetsusaponin FK2 (2), chikusetsusaponin FK3 (3), chikusetsusaponin FK4 (4), chikusetsusaponin FK5 (5), chikusetsusaponin FK6 (6), and chikusetsusaponin FK7 (7), and eleven known triterpenoid saponins, ginsenoside Rb3 (9), ginsenoside Rc (10), chikusetsusaponin VI (11), ginsenoside Re (12), ginsenoside Rg1 (13), pseudo-ginsenoside RS1 (14), notoginsenoside R1 (15), chikusetsusaponin L5) (17), chikusetsusaponin L10 (18), chikusetsusaponin IVa (19), and chikusetsusaponin V (20), were isolated from the fruits of Panax japonicus C. A. MEYER, collected in Kumamoto prefecture, Japan, and two new dammarane-type triterpenoid saponin, chikusetsusaponin FK5 (5) and chikusetsusaponin FM1 (8), and five known triterpenoid saponins, ginsenoside Rb3 (9), ginsenoside Rc (10), ginsenoside Re (12), ginsenoside Rg1 (13), and floralquinquenoside E (16), were isolated from the fruits of P. japonicus C. A. MEYER, collected in Miyazaki prefecture, Japan. The structures of new chikusetsusaponins were elucidated on the basis of chemical and physicochemical evidences.     

高效液相色谱-飞行时间质谱联用法分析人参及人参皂苷与山楂配伍过程中的水解行为

利用高效液相色谱-飞行时间质谱联用的方法,分别对人参配伍山楂前后人参皂苷的变化进行分析,同时对人参皂苷Re、Rg1、Rb1、Rd与山楂配伍的水解规律进行系统研究,并与单独煎煮液、仿山楂配伍pH值煎煮液的水解产物进行比较,结果发现人参与山楂配伍后人参皂苷Rg1、Rb1含量明显减少,而人参皂苷Re、Rd、Rg2、Rg3、F2、Rh1含量明显增加,其中人参皂苷Re与山楂配伍后水解产物为人参皂苷20(R)-Rg2、20(S)-Rg2,仿山楂配伍pH值水解产物为人参皂苷20(R)-Rg2、20(S)-Rg2、Rg4、Rg6;人参皂苷Rg1与山楂配伍后水解产物为20(S)-Rh1、20(R)-Rh1,仿山楂pH值水解产物为20(S)-Rh1、20(R)-Rh1、Rh4、Rk3;人参皂苷Rb1与山楂配伍后水解产物为Rd、20(S)-Rg3,仿山楂pH值水解产物为F2、20(S)-Rg3;人参皂苷Rd与山楂配伍后水解产物为F2、20(S)-Rg3、20(R)-Rg3,仿山楂pH值水解产物为20(S)-Rg3、20(R)-Rg3。研究表明,不同人参皂苷和山楂配伍后与仿山楂pH值的水解产物并不相同,人参与山楂配伍改变了人参皂苷成分的种类及含量。本研究为临床方剂中人参与山楂配伍后成分的变化提供物质基础数据。     

Major ginsenoside contents in rhizomes of Panax sokpayensis and Panax bipinnatifidus

This study compared eight major ginsenosides (Rg1, Rg2, Rf, Re, Rd, Rc, Rb1 and Rb2) between Panax sokpayensis and Panax bipinnatifidus collected from Sikkim Himalaya, India. High-performance liquid chromatographic analysis revealed that all major ginsenosides were present in the rhizomes of P. sokpayensis except ginsenoside Rc, whereas ginsenoside Rf, Rc and Rb2 were not detected in P. bipinnatifidus.     

In vivo metabolism study of ginsenoside Re in rat using high-performance liquid chromatography coupled with tandem mass spectrometry

Ginsenoside Re is one of the major the bioactive triterpene saponins in ginseng root, a well-known adaptogen in traditional Chinese medicine. It is believed that the lead compound may be further developed into a promising new drug for preventing hypertension and cardiovascular disease. To better understand the pharmacological activities of the component, an investigation of its in vivo metabolism was necessary. In the present study, a high-performance liquid chromatography coupled with electrospray ionization and quadrupole time-of-flight tandem mass spectrometry (HPLC-ESI-TOF-MS/MS) has been applied to discover and identify the metabolites of ginsenoside Re in rat urine following intravenous and oral administration of the component, respectively. The rat urine samples were collected and pretreated through C₁₈ solid-phase extraction cartridges prior to analysis. Negative electrospray ionization mass spectrometry was used to discern ginsenoside Re and its possible metabolites in urine samples. The metabolites were identified and tentatively characterized by means of comparing molecular mass, retention time, and fragmentation pattern of the analytes with those of the parent compound, ginsenoside Re. As a result, eleven and nine metabolites together with Re were detected and identified in rat urine collected after intravenous and oral administration, respectively. A possible metabolic pathway of ginsenoside Re was also investigated and proposed. Oxidation and deglycosylation were found to be the major metabolic processes of the constituent in rat.      

Chemical UPLC‐ESI‐MS/MS profiling of aconitum alkaloids and their metabolites in rat plasma and urine after oral administration of Aconitum carmichaelii Debx. Root extract

In this paper, an ultra high performance liquid chromatography tandem mass spectrometric (UPLC‐ESI‐MS/MS) method in positive ion mode was established to systematically identify and to compare the major aconitum alkaloids and their metabolites in rat plasma and urine after oral administration of Fuzi extract. A total twenty‐nine components including twenty‐five C19‐diterpenoid alkaloids and four C20‐diterpenoid alkaloids were identified in Fuzi extract. Thirteen of the parent components and five metabolites were detected in rat plasma and sixteen parent compounds and six metabolites in urine. These parent components found in rat plasma and urine were mainly C19‐diterpenoid alkaloids. All of the metabolites in vivo were demethylated metabolites (phase I metabolites), which suggested that demethylation was the major metabolic pathway of aconitum alkaloids in vivo. A comparison of the parent components in rat plasma and urine revealed that 3‐deoxyacontine was found in plasma but not in urine, while kalacolidine, senbusine and 16‐β‐hydroxycardiopetaline existed in urine but not in plasma, which indicated that most alkaloids components were disposed and excreted in prototype form. This research provides some important information for further metabolic investigations of Fuzi in vivo.