Pharmacokinetics of the prototype and hydrolyzed carboxylic forms of ginkgolides A, B, and K administered as a ginkgo diterpene lactones meglumine injection in beagle dogs.

Ginkgo diterpene lactones meglumine injection (GDLI) is a commercially available product used for neuroprotection. However, the pharmacokinetic properties of the prototypes and hydrolyzed carboxylic forms of the primary components in GDLI, i.e., ginkgolide A (GA), ginkgolide B (GB), and ginkgolide K (GK), have never been fully evaluated in beagle dogs. In this work, a simple, sensitive, and reliable method based on ultra-fast liquid chromatography-tandem mass spectrometry (UFLC-MS/MS) was developed, and the prototypes and total amounts of GA, GB, and GK were determined in beagle dog plasma. The plasma concentrations of the hydrolyzed carboxylic forms were calculated by subtracting the prototype concentrations from the total lactone concentrations. For the first time, the pharmacokinetics of GA, GB, and GK were fully assessed in three forms, i.e., the prototypes, the hydrolyzed carboxylic forms, and the total amounts, after intravenous administration of GDLI in beagle dogs. It was shown that ginkgolides primarily existed in the hydrolyzed form in plasma, and the ratio of hydrolysates to prototype forms of GA and GB decreased gradually to a homeostatic ratio. All of the three forms of the three ginkgolides showed linear exposure of AUC to the dosages. GA, GB, and GK showed a constant half-life approximately 2.7, 3.4, and 1.2 h, respectively, which were consistent for the forms at three dose levels (0.3, 1.0, and 3.0 mg·kg-1) and after a consecutive injection of GDLI for 7 days (1.0 mg·kg-1).

Qualitative and quantitative analysis of major constituents from Dazhu Hongjingtian capsule by UPLC/Q-TOF-MS/MS combined with UPLC/QQQ-MS/MS.

In this work, a sensitive and efficient method was established and validated for qualitative and quantitative analysis of major bioactive constituents in Dazhu Hongjingtian capsule by liquid chromatography tandem mass spectrometry. A total of 32 compounds were tentatively identified using ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. Furthermore, 12 constituents, namely gallic acid, 3,4-dihydroxybenzoic acid, salidroside, p-coumaric acid-4-O-ß-d-glucopyranoside, bergeninum, 4-hydroxybenzoic acid, 4-hydroxyphenylacetic acid, syringate, 6''-O-galloylsalidroside, rhodiosin, rhodionin and kaempferol-7-O-α-l-rhamnoside, were simultaneously quantified by the developed ultra-performance liquid chromatography coupled with a triple quadrupole mass spectrometry method in 9 min. All of them were analyzed on an Agilent ZorBax SB-C18 column (3.0 × 100 mm, 1.8 µm) with linear gradient elution of methanol-0.1% formic acid water. The proposed method was applied to analyze three batches of samples with acceptable linearity (R, 0.9979-0.9997), precision (RSD, 1.3-4.7%), repeatability (RSD, 1.7-4.9%), stability (RSD, 2.2-4.9%) and recovery (RSD, 0.6-4.4%) of the 12 compounds. As a result, the analytical method possessing high throughput and sensitivity is suitable for the quality control of Dazhu Hongjingtian capsule.

Impact of parameter fluctuations on the performance of ethanol precipitation in production of Re Du Ning Injections, based on HPLC fingerprints and principal component analysis.

The present study was designed to determine the relationships between the performance of ethanol precipitation and seven process parameters in the ethanol precipitation process of Re Du Ning Injections, including concentrate density, concentrate temperature, ethanol content, flow rate and stir rate in the addition of ethanol, precipitation time, and precipitation temperature. Under the experimental and simulated production conditions, a series of precipitated resultants were prepared by changing these variables one by one, and then examined by HPLC fingerprint analyses. Different from the traditional evaluation model based on single or a few constituents, the fingerprint data of every parameter fluctuation test was processed with Principal Component Analysis (PCA) to comprehensively assess the performance of ethanol precipitation. Our results showed that concentrate density, ethanol content, and precipitation time were the most important parameters that influence the recovery of active compounds in precipitation resultants. The present study would provide some reference for pharmaceutical scientists engaged in research on pharmaceutical process optimization and help pharmaceutical enterprises adapt a scientific and reasonable cost-effective approach to ensure the batch-to-batch quality consistency of the final products.

Research on the change of chemical composition in productive process of Re Du Ning injection by HPLC/Q-TOF MS.

A high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (HPLC/Q-TOF MS) was developed for the analysis of chemical composition change in the production process of Re Du Ning injection, a Chinese medicine preparation with a combination of Lonicera japonica Thunb., Gardenia jasminoides Ellis and Artemisia annua L. A total of 90 compounds from raw materials-intermediates-Re Du Ning injection were detected; among them, 55 compounds were identified or tentatively characterized, and the characteristic ions of different types of compounds were described. Based on these studies, the different types of compounds in the various process routes were analyzed. A total of 28 compounds, including seven iridoid glycosides and six monoterpenes from G. jasminoides Ellis, five iridoid glycosides, nine phenolic acids and one unknown compound from L. japonica Thunb., were transferred to Re Du Ning injection, and two unknown compounds were generated in the production process of Re Du Ning injection. The results indicated that the Chinese Medicine Pharmaceutical process control is very important. This method could provide some reference for other Chinese medicine preparations.

[Metabolism of six saponins by rat intestinal bacteria in vitro].

To investigate the metabolism of six saponins by rat intestinal bacteria in vitro.Six saponins, including notoginsenoside R1, ginsenoside Rg1, ginsenoside Rg2, ginsenoside Re, ginsenoside Rd and ginsenoside Rb1, were incubated for 8 and 24 h with rat intestinal bacteria under anaerobic environment, respectively. After the samples were precipitated by acetonitrile and extracted with ethyl acetate, LC-Q-TOF-MS/MS was applied for the qualitative analysis of the metabolites. The potential metabolites in rat feces were analyzed by comparing the total ion current of the test samples and blank samples and analyzing the quasi-molecular ion and fragment ion of all chromatograms. The results showed that six saponins could be easily metabolized by rat intestinal bacteria. Notoginsenoside R1 was mainly metabolized into five metabolites, and it's metabolic pathway was notoginsenoside R1→ginsenoside Rg1→ginsenoside Rh1 and ginsenoside F1→protopanaxatriol→dehydrogenated protopanaxatriol. Ginsenoside Rg1 was mainly metabolized into four metabolites, and it's metabolic pathway was ginsenoside Rg1→ginsenoside Rh1 and ginsenoside F1→protopanaxatriol→dehydrogenated protopanaxatriol. Ginsenoside Rg2 was mainly metabolized into two metabolites, and it's metabolic pathway was ginsenoside Rg2→ protopanaxatriol→dehydrogenated protopanaxatriol. Ginsenoside Re was mainly metabolized into four metabolites, and it's metabolic pathway was ginsenoside Re→ginsenoside Rg2→ginsenoside F1→protopanaxatriol→dehydrogenated protopanaxatriol. Ginsenoside Rd was mainly metabolized into four metabolites, and it's metabolic pathway was ginsenoside Rd→ginsenoside Rg3 and ginsenoside F2→ginsenoside Rh2→protopanaxadiol. Ginsenoside Rb1 was mainly metabolized into five metabolites, and it's metabolic pathway was ginsenoside Rb1→ginsenoside Rd→ginsenoside Rg3 and ginsenoside F2→ginsenoside Rh2→protopanaxadiol. In summary, six saponins could be quickly metabolized by rat intestinal bacteria in vitro. Their major metabolic pathways were deglycosylation and dehydrogenation.

[Determination of five kinds of trace ginkgolic acids in diterpene ginkgolides meglumine injection materials by LC-MS/MS].

To develop a LC-MS/MS method for the determination of five kinds of trace ginkgolic acids in diterpene ginkgolides meglumine injection materials, the column was Agilent ZORBAX Eclipse plus C18 (3.0 mm x 50 mm, 1.8 µm), and the mobile phase consisted of methanol-water (containing 0.2% formic acid) (95:5) at a flow rate of 0.5 mL · min(-1). The multiple reaction ion monitoring (MRM) with an ESI interface in the negative ion mode was selected. The results showed that the linear ranges of five kinds of ginkgolic acids were in the range of 0.2-36.0 µg · L(-1) (r ≥ 0.999 5). The lowest limit of quantification (LOQ) of ginkgo acid C13: 0, C15:1, C17:2, C15:0 and C17:1 were 0.18, 0.18, 0.21, 0.10 and 0.20 µg · L(-1), respectively. The average recovery was between 73.28% and 87.56%, and the average content of total ginkgolic acids in three batches of samples was in the range of 0.023-0.028 µg · g(-1), which was much lower than 2 µg · g(-1) prescribed in drug registration standards. This method is simple and rapid with high sensitivity, which can be used for the determination of five kinds of trace ginkgolic acids in diterpene ginkgolides meglumine injection materials.

[Quantitative and qualitative evaluation on tablets of Ginkgo biloba leaves using fingerprint and LC-MS analysis].

A reasonable method for the quality control of tablets of Ginkgo biloba leaves was established in this paper. The total flavonol glycosides and terpene lactones of G. biloba tablets were quantified by HPLC. Totally, 16 batches of the commercially available tablets of G. biloba leaves were determined. Among of them, 2 batches were unqualified in the content of total flavonol glycosides, and 3 batches were unqualified in the content of terpene lactones. A validated HPLC fingerprint method was established to evaluate the commercially available tablets of G. biloba leaves with the assistance of LC-MS. Sixteen batches showed the similarity of 0.763-0.989. There were 31 fingerprint chromatogram peaks were identified as flavonoids compositions by LC-MS. This provides a research idea for the quality control of tablets of G. biloba leaves.

[Similarity between leaves of Nauclea officinalis and stems of Nauclea officinalis].

The study is to develop a method to determine 3 batches leaves of Nauclea officinalis and stems of N. officinalis by HPLC. The differences between strictosamide contents and fingerprints was compared, then chromatographic peak of fingerprints was validated with the assistance of LC-MS. The strictosamide contents in stems of N. officinalis were higher than leaves of N. officinalis. The main chemical composition in leaves of N. officinalis and stems of N. officinalis were alkaloid which revealed by LC-MS. There are 7 chemical compositions were same between them, but the chemical composition in leaves of N. officinalis is more than stems of N. officinalis. This provides a scientific basis for the development of the potential medicinal value of leaves of N. officinalis and the sustainable utilization of N. officinalis.

[Study on limit detection of flavones in diterpene ginkgolides meglumine injection materials by LC-MS and HPLC-DAD].

Limit test of flavones in diterpene ginkgolides meglumine injection materials by UV-Vis and HPLC-DAD method was studied in this essay. The HPLC-DAD method has lower LOD (about 1% of the UV-Vis), that is, the sensitivity is higher than UV-Vis method. Through the analysis of the kinds of flavonoids ingredients in the samples by LC-MS, the three compounds with highest contents are kaempferol, quercetin and isorhamnetin. Kaempferol, quercetin and isorhamnetin were chosen as reference compounds for HPLC analysis, and the HPLC separation analysis was carried on an Agilent Eclipse plus C18 column (4.6 mm x 250 mm, 5 µm) with methanol and water containing 0.4% phosphoric acid (50: 50) as mobile phase, and the flow rate was 1.0 mL x min(-1). The detection wavelength was set at 360 nm. This method has good specificity, precision and reproducibility. The LODs of quercetin, kaempferide and isorhamnetin were 27.6, 22.3, 29.5 µg x L(-1). The average recovery was 87.9% (RSD 3.3%), 91.7% (RSD 3.1%), 88.3 (RSD 1.3%) for quercetin, kaempferide and isorhamnetin, respectively. Based on the 10 batches of sample results and sensitivity of different HPLC, the content of total flavonoids ingredients of diterpene ginkgolides meglumine injection materials was limited no more than 2 x 10(-5). This method is simple, quick and has good maneuverability, and could be used to the limit test of flavonoids in the diterpene ginkgolides meglumine injection materials.

[Rapid identification of six chemical constituents in Guizhi Fuling capsule by DART-Q-TOF-MS].

In order to establish a rapid method for identifying six constituents in Guizhi Fuling capsule, Q-TOF with DART ion source was used to perform the direct analysis of compounds in Guizhi Fuling capsule. The DART sampler delivery rate was 0.2 mm s(-1). The temperature of helium gas of DART was 450 degrees C. The capillary voltage was kept at 1 000 V. The temperature of the drying gas of Agilent 6538 Q-TOF MS was set at 350 degrees C. The flow rate of the drying gas of MS was set at 3.5 L x min(-1). The MS scan range was m/z 50-1 000. Based on accurate mass measurements and the elemental compositions of the product ions and fragmentation patterns of reference conpounds, six components, amygdalin, paeonol, paeoniflorin, cinnamic acids, gallic acid, benzoic acid were identified rapidly. The method can rapidly identify six chemical constituents in three batch of Guizhi Fuling capsule. The DART-Q-TOF-MS method is simple, rapid and specific and it can be used for rapid identification and characterization of compounds in traditional Chinese medicines.

[Quality evaluation of guizhi fuling capsule using self-control method of reference Chinese medicine preparation].

Taking guizhi fuling capsule (GZFL) for instance, a new method about reference Chinese medicine preparation which was used as standard substance for the quality evaluation of complex Chinese medicine preparation by the fingerprint of reference preparation instead of standard fingerprint was proposed. It could eliminate the errors from different instruments, chromatographic columns and solve the problem of similarity matching in the absence of standard fingerprint. The qualification of reference GZFL was evaluated according to the quality control method of GZFL from Chinese Pharmacopoeia. Then multiple batches of GZFL were estimated, taking fingerprint of reference preparation and standard fingerprint as references, respectively, at different instruments and chromatographic columns. Finally, the packaging and expiration date for reference GZFL were confirmed according to the results of stability investigation. The results indicated that the fingerprint of reference GZFL could be used to assess the quality of GZFL better than standard fingerprint. The data of accelerated stability and long-term stability test demonstrated that reference GZFL was stable in the conditions of double blister package. Therefore, reference GZFL can be used as standard substance in quality control of GZFL.

Antioxidant and anti-inflammatory activities of six flavonoids separated from licorice.

Licorice, the roots and rhizomes of several Glycyrrhiza species (Leguminosae), is an important natural sweetening agent and a widely used herbal medicine. In this work, six flavonoids, 5-(1,1-dimethylallyl)-3,4,4'-trihydroxy-2-methoxychalcone (1), licochalcone B (2), licochalcone A (3), echinatin (4), glycycoumarin (5) and glyurallin B (6), were isolated from the extracts of licorice (Glycyrrhiza inflata and Glycyrrhiza uralensis). Their structures were elucidated using various spectroscopic methods. To our knowledge, compound 1 was isolated from natural plants for the first time. All the isolates were tested by antioxidant and anti-inflammatory assays. Compounds 2, 4 and 5 showed strong scavenging activity toward the ABTS(+) radical, and compounds 1, 2, 3, 5 and 6 exhibited potent inhibition of lipid peroxidation in rat liver microsomes compared with the reference controls. Compounds 1-4 dose-dependently inhibited LPS induced reactive oxygen species (ROS) production in RAW 264.7 cells. Furthermore, compounds 1-5 were demonstrated to inhibit the production of nitric oxide (NO), interleukin-6 (IL-6) and prostaglandin E2 (PGE2) in LPS-induced macrophage cells. Moreover, the contents of the six compounds, in different Glycyrrhiza species, were quantified by HPLC-MS.

The evaluation and implementation of Direct Analysis in Real Time quadrupole time-of-flight tandem mass spectrometry for characterization and quantification of geniposide in Re Du Ning Injections.

RATIONALE: The Direct Analysis in Real Time (DART) ionization source coupled with a quadrupole time-of-flight tandem mass spectrometry (Q-TOF MS/MS) system has the capability to desorb analytes directly from samples from complex Chinese herbal preparations without sample cleanup or chromatographic separation. METHODS: In this work, a method based on DART/Q-TOF MS/MS has been developed for rapid determination of geniposide present in 'Re Du Ning Injections', a Chinese herbal preparation. The method has been evaluated for both qualitative and quantitative analysis of geniposide in Re Du Ning Injections. RESULTS: Variables including polarity for ion detection, DART gas heater temperature, matrix effect and sample presentation speed were investigated. The quantitative method was validated with respect to linearity, sensitivity, repeatability, precision and accuracy by using both internal and external standards. A comparison of the results obtained using the DART-based method was made with those obtained using a conventional High-Performance Liquid Chromatography/Diode-Array Detector (HPLC/DAD) by analyzing geniposide in four batches of Re Du Ning Injections. CONCLUSIONS: The DART/Q-TOF MS/MS-based method provides a rapid, efficient and powerful method to analyze compounds from complex Traditional Chinese Medicines with limited sample preparation thus reducing time and complexity of quality control for those materials.

Identification and quantification of free radical scavengers in the flower buds of Lonicera species by online HPLC-DPPH assay coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry.

Flos Lonicerae, derived from the flower buds of several medicinal Lonicera species, is a commonly used herbal medicine with multiple pharmacological activities, one of the major ones being antioxidant activity. In this study, free radical scavengers in the flower buds of six Lonicera species were screened, identified and quantified by online HPLC-DPPH (1,1-diphenyl-2-picrylhydrazyl) assay coupled with LC quadrupole time-of-flight tandem mass spectrometry (Q-TOF MS/MS). The antioxidants were firstly screened from the complex plant matrix by the online HPLC-DPPH assay. Then the active compounds were identified by LC Q-TOF MS/MS, and the possible fragmentation pathways were proposed. The reactivity of antioxidants available was investigated using an internal standard method by online LC assay. The contents of 12 antioxidants were also determined or estimated by HPLC coupled with diode array detector. The total antioxidant capability determined by the online method was used as the marker to evaluate the quality of Flos Lonicerae. The results were important to clarify the material basis and therapeutic mechanism of Flos Lonicerae.

Screening and characterization of natural antioxidants in four Glycyrrhiza species by liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry.

Licorice, derived from the dried roots and rhizomes of several species of genus Glycyrrhiza L. (Leguminosae family), has been traditionally used in herbal medicine for over 4000 years. In recent years, the interest in antioxidative constituents in licorice has greatly increased. In this work, a new method based on 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) spiking test combined with HPLC coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (Q-TOF MS/MS) analysis was developed to screen and identify the antioxidants in licorice. The results of the method validation indicated that the developed method was reliable and repeatable. Compared with DPPH on-line method, the HPLC-Q-TOF MS/MS method combined with DPPH spiking test offered much higher sensitivity and resolution. Using this method, 35 radical scavengers were screened from four Glycyrrhiza species (G. inflata, G. glabra, G. pallidiflora and G. uralensis), and 21 of them were unambiguously or tentatively identified by HPLC-Q-TOF MS/MS. Among the 21 identified flavonoids, 10 compounds had been reported to possess antioxidative activities in the previous studies, and the radical scavenging activities of the other 11 compounds were reported for the first time. The effects of six purified flavonoids on DPPH radical and lipid peroxidation were evaluated for validation of the developed method. The results indicated that HPLC-Q-TOF MS/MS coupled with DPPH treatment is an efficient and powerful method to discover the potential antioxidative compounds from the complex natural product mixtures. In this study, the identified components with free radical scavenging activity, would help to explain the therapeutic benefit of licorice in the treatment of human disease associated with oxidative stress.

Characterization and identification of saponins in Achyranthes bidentata by rapid-resolution liquid chromatography with electrospray ionization quadrupole time-of-flight tandem mass spectrometry.

A rapid-resolution liquid chromatography (RRLC) method coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (Q-TOF MS/MS) has been developed for analysis of oleanane-type triterpenoid saponins in Achyranthes bidentata. Collision-induced dissociation techniques were used to fragment the precursor molecular ions and the resulting product ions. A retro-Diels-Alder rearrangement from the oleanane aglycone skeleton in the MS/MS process yielded characteristic fragment ions in positive ion mode. These characteristic ions were helpful in predicting the aglycone structure. Losses of monosaccharide sequences, presence of sugar-chain fragment ions, and cleavage of CO(2) were observed for important information on sugar types and attachment sequences. Fragmentation rules of three major groups of saponins from A. bidentata were summarized, and the possible fragmentation pathways were proposed. A total of 22 compounds including both the target and unknown oleanane-type triterpenoid saponins were rapidly screened and predicted in the herbal extract by the developed method. The RRLC-Q-TOF MS/MS method has provided a powerful approach for rapid separation, target screening and structural elucidation of oleanane-type saponins, and also opened perspectives for similar studies on other herbal medicines.

Identification of metabolites of Danggui Buxue Tang in rat urine by liquid chromatography coupled with electrospray ionization time-of-flight mass spectrometry.

A method coupling liquid chromatography with electrospray ionization time-of-flight mass spectrometry (LC/ESI-TOF/MS) has been developed for rapid and sensitive analysis of rat urinary metabolite profile of Danggui Buxue Tang (DBT), a well-known Chinese herbal formula. After oral administration of DBT, urine samples were collected during 0-24 h, and then pretreated by solid-phase extraction. A total of 68 compounds including 13 parent compounds and 55 metabolites were detected in the drug-containing urines compared with blank urines. The total analytical time was less than 20 min. Metabolites of DBT were identified using dynamic adjustment of the fragmentor voltage to produce structure-relevant fragment ions. By using this approach, the mass accuracy of precursor and fragment ions was typically within +/-5 ppm of the theoretical values, and enabled the identification of 43 metabolites including 27 isoflavanoid and 16 phthalide metabolites. Our results indicated that glucuronidation and sulfation were the major metabolic pathways of isoflavonoids, while glutathione conjugation, glucuronidation and sulfation were the main metabolic pathways of phthalides. No saponin-related metabolites were detected. The results of the present study provided important structural information relating to the metabolism of DBT. Furthermore, this work demonstrated the potential of the LC/ESI-TOF/MS approach for identification of metabolites from Chinese herbal medicines in urine.

Application of liquid chromatography-electrospray ionization time-of-flight mass spectrometry for analysis and quality control of compound Danshen preparations.

A liquid chromatography coupled with electrospray ionization time-of-flight mass spectrometry (LC-ESI-TOF-MS) method has been developed to evaluate the quality of three formulas of compound Danshen preparations (CDPs), through a simultaneous determination of 22 marker constituents (nine major phenolic acids, eight major saponins and five major diterpenoids). Optimum separations were obtained with a Zorbax C(18) column, using a gradient elution with 0.1% aqueous formic acid and acetonitrile. Limits of detection and quantification were in ranges of 1.58-10.10 and 4.85-28.56 ng/mL. All calibration curves showed good linear regression (r(2 ) > 0.9900) within the test range, and the recoveries were between 78.4 and 103.1% for all analytes. The assay was successfully utilized to analyze the 22 marker components in 26 samples. The overall results demonstrated that this method is sensitive, accurate and reliable for the quality control of CDPs.

Simultaneous qualification and quantification of eight triterpenoids in radix achyranthis bidentatae by high-performance liquid chromatography with evaporative light scattering detection and mass spectrometric detection.

An HPLC with evaporative light scattering detection (ELSD) and ESI-MS was established for the simultaneous determination of eight triterpenoids in Radix Achyranthis Bidentatae. The optimal chromatographic conditions were achieved on a Zorbax C18 column by linear gradient elution with 0.08% v/v aqueous formic acid and ACN as the mobile phase at the flow rate of 0.8 mL/min. Temperature for the detector drift tube was set at 101 degrees C and the nitrogen flow rate was 2.8 L/min. The identities of the analytes were accomplished by comparing retention times and mass data with those of reference compounds. The validation of the method included tests of linearity, sensitivity, repeatability, recovery, and stability. All the calibration curves of the eight triterpenoids showed good linear regression (R2 >0.997) within the test ranges. The method provides desirable repeatability with overall intra- and interday variations of less than 4.9%. The obtained recoveries varied between 93.6 and 98.1% while the RSDs were below 3.9% (n = 3). The analysis results indicate that the content of investigated triterpenoids in Radix Achyranthis Bidentatae from different locations was greatly diverse, and the triterpenoids could be used as chemical markers for the discrimination of genuine and ungenuine crude drugs.