Elution System Research Articles

Implications for the biofunctionalization of drug-eluting devices at the example of a site-selective antibody modification for drug eluting stents

AbstractFunctionality of implant surfaces is considerably determined by the conformations of immobilized biomolecules adjustable by the applied surface modification approach. Moreover, surface modification of drug eluting systems often needs to be thoroughly optimized with regard to possible drug losses associated with a loss of functionality. Here, we thoroughly investigate biomolecule surface loading, functionality, morphology and stability in dependence of modification conditions at the example of a site-selective immobilization of anti-CD34 antibodies (CD34-Ab) to drug-eluting stents with the aim of providing general information on the biofunctionalization of drug eluting systems. In this context, we demonstrate that the reaction time of biomolecule immobilization defines achievable surface loads but also drug loss. We could moreover show that the used site-selective immobilization procedure elevated the surface functionality considerably in comparison to surfaces modified by random physisorption. Furthermore investigated bionfunctional stability gives important indications for storage conditions of biofunctionalized implants.

ISOLASI DAN IDENTIFIKASI KOMPONEN KIMIA EKSTRAK N-HEKSAN DAUN PALA (Myristica fragrans)

Nutmeg plant is a multi-purpose plant because each part can be utilized in the industry. Nutmeg leaves contain essential oils and phenolic compounds. Essential oils are used as traditional medicine ingredients and as raw material for the manufacture of cosmetics, soaps, perfumes and others. This study aimed to isolate and identify the chemical components in the leaves of nutmeg (Myristica fragrans). Have done isolation and Identification of chemical components of the methanol extract of leaves pala ( Myristica fragrans .) of 500 grams to determine the class of chemical components caontained in the leaf pala ( Myristica fragrans .). The methanol extract which obtained by maseartion method 9,45 grams continued by solid liquid partition with n-hexane 4,61 grams extract. N-hexan extract isolated by column chromatography method obtained 37 bottles vials. Fraction D of the merger based on the appearance of spotting the chromatograms isolated by preparative thin-layer chromatography method, obtained 3 band. D.1 fractions isolated by TLC obtained a stain. In fractions spotting D.1 is obtained by testing a single two-dimentional TLC ang the elution system of multi eluen. Interpretation UV-Visible spectra data showed maximum absorption at a wavelength 0f 2 73 nm and showed infrared fungtional group (OH) on the wave number (3 927.78 cm -1 , 3828.59 cm -1 , 3743.30 cm -1 , 3387.93 cm -1 ), group (CH) on the wave number ( 2925.93 cm -1 , 2859.02 cm -1 , 2364.17 cm -1 ), alken group (C = C) aromatik on the wave number ( 1642.54 cm -1 , 1565.88 cm -1 , 1516.65 cm -1 , 1458.92 cm -1 , 1114.33 cm -1 ), benzene group on the wave number ( 698.24 cm -1 ). Single spots obtained gave a positive reaction to spotting visualizer class of flavonoids. Key words : Nutmeg , Isolation, Essential Oils.

Trifluoroethanol-containing RP-HPLC mobile phases for the separation of transmembrane peptides human glycophorin-A, integrin alpha-1, and p24: analysis and prevention of potential side reactions due to formic acid.

Reversed-phase high-pressure liquid chromatography analysis and purification of three hydrophobic, aggregation-prone peptides, composed mainly of the transmembrane (TM) sequence, were performed using elution systems containing 2,2,2-trifluoroethanol (TFE). The addition of 10-16% TFE to a common mobile phase, such as a water/acetonitrile/propanol (PrOH) or a water/PrOH/formic acid system, markedly improved the chromatographic separation of these peptides. The superior performance of TFE-containing systems in separating peptides over water/PrOH/formic acid systems [Bollhagen R. et al., J. Chromatogr. A, 1995; 711: 181-186.] clearly demonstrated that adding TFE to the mobile phase is one of best methods for TM-peptide purification. Characterization of the potential side reactions using MALDI and ESI-LIT/Orbitrap mass spectrometry indicated that prolonged incubation of peptides in a mixture of TFE-formic acid possibly induces O-formylation of the Ser residue and N-formylation of the N-terminus of peptides. The conditions for selective removal of the formyl groups from TM peptides were also screened. We believe that these results will expand our ability to analyze and prepare hydrophobic, aggregation-prone TM peptides and proteins.

Determination of polychlorinated biphenyls by liquid chromatography-atmospheric pressure photoionization-mass spectrometry.

This study presents the atmospheric pressure photoionization (APPI) of high-chlorinated (five or more chlorine atoms) polychlorinated biphenyls (PCBs) using toluene as dopant, after liquid chromatographic separation. Mass spectra of PCB 101, 118, 138, 153, 180, 199, 206 and 209 were recorded by using liquid chromatography-APPI-tandem mass spectrometry (LC-APPI-MS/MS) in negative ion full scan mode. Intense peaks appeared at m/z that correspond to [M - Cl + O](-) ions, where M is the analyte molecule. Furthermore, a detailed strategy, which includes designs of experiments, for the development and optimization of LC-APPI-MS/MS methods is described. Following this strategy, a sensitive and accurate method with low instrumental limits of detection, ranging from 0.29 pg for PCB 209 to 8.3 pg for PCB 101 on column, was developed. For the separation of the analytes, a Waters XSELECT HSS T3 (100 mm × 2.1 mm, 2.5 µm) column was used with methanol/water as elution system. This method was applied for the determination of the above PCBs in water samples (surface water, tap water and treated wastewater). For the extraction of PCBs from water samples, a simple liquid-liquid extraction with dichloromethane was used. Method limits of quantification, ranged from 4.8 ng l(-1), for PCB 199, to 9.4 ng l(-1), for PCB 180, and the recoveries ranged from 73%, for PCB 101, to 96%, for PCB 199. The estimated analytical figures were appropriate for trace analysis of high-chlorinated PCBs in real samples.

Characterization and Identification of the Chemical Compositions in a Traditional Uighur Medicine Prescription Yizhihao Granule by LC–ESI-QTOF-MS

An efficient method was developed and established for the rapid analysis of a traditional Uighur medicinal prescription, Yizhihao granule, by liquid chromatography-Quadrupole time-of-flight tandem mass spectrometry. HPLC was performed with a Poroshell 120-EC18 column with 2.7 µm particle size using A gradient elution system. A quadrupole time-of-flight analyzer was used for the determination of accurate mass of the protonated or deprotonated molecules and fragment ions. Sixty-six constituents including amino acids, organic acids (aliphatic acids, benzoic acid derivatives, and chlorogenic acids), alkaloids (indole and quinazolinone type), flavonoids (C,O-glycoside, C-glycosides, O-glycosides, and aglycone), sesquiterpenoids (rupestonic acid derivatives), and other compounds were identified or tentatively characterized in Yizhihao granule as a presented application of prescription according to the accurate mass, MS/MS data, and relevant literature. Additionally, the fragmentation pathways of two rupestonic acid derivatives were proposed. The relationship between structure features and fragmentation patterns were investigated thoroughly and applied in the on-line analysis to deduce the composition of traditional Uighur herbal prescription. The present method and results should be beneficial in the development of traditional Uighur herbal prescription.

A Combination of Isocratic and Gradient Elution Modes in HPLC with the Aid of Time-Overlapping Process for Rapid Determination of Methyldopa in Human Urine

A new rapid time-overlapping high-performance liquid chromatography method using coupled-column double-injection technique with fluorescence detection has been developed and validated to determine methyldopa (MTD) in human urine. The method was based on injecting a new sample onto the second column before finalizing the cleanup and the re-equilibration of the first column for the former sample. A combination of isocratic and gradient elution was employed according to a pre-set program. At the beginning, isocratic step of acetate buffer solution (0.1 M, pH 2.4) was set until 7 min. Subsequently, a gradient elution step using acetate buffer (0.1 M, pH 2.4) as mobile phase A and acetonitrile as mobile phase B was employed. After the end of each gradient step, the column was re-equilibrated with 4 mL of the starting isocratic elution system before the next analysis. The overall cycle time was 7 min per each sample. The calibration curve was linear over the concentration range of 0.1–40 µg/mL MTD. The overall mean recoveries were in the range of 98.29–101.39%. The applicability of the method was successfully evaluated by monitoring the incremental urinary excretion of MTD in human urine over 12 hr after a single oral administration of 250 mg.

Simultaneous determination of 10 active components in Baizhu Shaoyao San and its single herbs by high-performance liquid chromatography coupled with diode array detection.

Baizhu Shaoyao San (BSS) is a famous traditional Chinese medicinal prescription, which is composed of Rhizome atractylodis macrocephalae, Radix Paeoniae Alba, Pericarpium Citri Reticulatae and Radix Saposhnikovia. In this study, a simple and sensitive high-performance liquid chromatography coupled with diode array detection method was established for the simultaneous determination of 10 marker compounds including atractylenolide I, gallic acid, albiflorin, paeoniflorin, narirutin, hesperidin, nobiletin, cimifugin, prim-O-glucosylcimifugin, 4'-O-β-d-glucosyl-5-O-methylvismminol in BSS and its single herbs. The chromatographic separation was performed using a YMC C18 column with a gradient elution system of acetonitrile and 0.1% formic acid aqueous solution at a flow rate of 1 mL/min. The results demonstrated that the validated method was simple, reliable and successfully applied to evaluate the selected compounds in BSS and its single herbs for quality control. Moreover, the experimental data showed that the contents of two major active components detected in BSS decoction were significantly higher than those in the single herbs, which indicated that the combination of single herbs could result in the difference in the amount of active constituents.

Fractionation of complex lipid mixtures by hydroxyapatite chromatography for lipidomic purposes

The comprehensive analysis of natural lipid mixtures is often challenging due to the simultaneous occurrence of functionally and structurally heterogeneous compounds. Modern analytical approaches in system-wide lipidomics essentially rely on mass spectrometry (MS). The overabundant amount of triacylglycerols (TAGs) in most samples hinders the direct detection of phospholipids (PLs) or other low-abundance lipids; therefore, a fractionation step is most often required to reduce sample complexity prior to MS analysis. In this work, we explore the use of hydroxyapatite (HAP) as a chromatographic stationary phase (gel HAP) or chemo-affinity sorbent material (ceramic HAP) to selectively enrich PLs and polar lipids from chicken egg yolk and buttermilk. Due to the affinity of phosphate-containing compounds for HAP, both in-column and in-batch HAP-based chromatography were effective to deplete TAGs before releasing PLs with an eluting ternary system containing sodium phosphate as the displacing agent. Buttermilk gangliosides and PLs co-eluted, indicating that HAP also exhibits a high affinity for sialylated glycolipids and that polar lipids are retained through a combined mechanism of chemo-affinity and hydrogen bonding. To the best of our knowledge, this is the first report in which HAP is proposed as an alternative stationary phase for separating both the PLs and sialylated glycolipids from TAGs in complex lipidomes. The HAP-based chromatography has potential to be improved for the separation of the polar lipid classes.

Diversification in the Supply Chain of (99)Mo Ensures a Future for (99m)Tc.

The uncertain availability of (99m)Tc has become a concern for nuclear medicine departments across the globe. An issue for the United States is that currently it is dependent on a supply of (99m)Tc (from (99)Mo) that is derived solely by production outside the United States. Since the United States uses half the world's (99)Mo production, the U.S. (99)Mo supply chain would be greatly enhanced if a producer were located within the United States. The fragility of the old (99)Mo supply chain is being addressed as new facilities are constructed and new processes are developed to produce (99)Mo without highly enriched uranium. The conversion to low-enriched uranium is necessary to minimize the potential misuse of highly enriched uranium in the world for nonpeaceful means. New production facilities, new methods for the production of (99)Mo, and a new generator elution system for the supply of (99m)Tc are currently being pursued. The progress made in all these areas will be discussed, as they all highlight the need to embrace diversity to ensure that we have a robust and reliable supply of (99m)Tc in the future.

New Coating Method for Sustained Drug Release: Surface Modification of ePTFE Grafts by inner coating PLGA

Division of Nephrology, Samsung Medical Center, Sungkyunkwan University of School of Medicine, Seoul 135-710, KoreaReceived December 24, 2013, Accepted January 6, 2014Expanded polytetrafluoroethylene (ePTFE) grafts have been used as vascular access for many patientssuffering from end stage renal disease. However, the vascular graft can cause significant clinical problems suchas stenosis or thrombosis. For this reason, many studies have been performed to make drug eluting graft, butinitial burst is major problem in almost drug eluting systems. Therefore we used biodegradable polymer toreduce initial burst and make sustained drug delivery. The ePTFE grafts were dipped into a paclitaxel-dissolvedsolution and then PLGA-dissolved solution was passed through the lumen of ePTFE. We analyzed whether thedose of paclitaxel is enough and the loading amount of PLGA on ePTFE graft increases according to the coatingsolution’s concentration. Scanning electron microscope (SEM) images of various concentration of PLGAshowed that the porous surface of graft was more packed with PLGA by tetrahydrofuran solution dissolvedPLGA. In addition, in vitro release profiles of Ptx-PLGA graft demonstrated that early burst was graduallydecreased as increasing the concentration of PLGA. These results suggest that PLGA coating of Ptx loadedgraft can retard drug release, it is useful tool to control drug release of medical devices.Key Words : Hemodialysis, Vascular access, ePTFE graft, Paclitaxel, Biodegradable polymerIntroductionMany patients suffering from end stage renal diseaseusually receive hemodialysis three times a week. To performthe hemodialysis, the secure of vascular access is important.Most common forms of vascular access are the nativearteriovenous fistulas (AVF) and arteriovenous graft (AVG)using expanded polytetrafluoroethylene (ePTFE) graft.

Determination and pharmacokinetic study of the novel anti-tumor candidate drug DG-7 in rat plasma by liquid chromatography-tandem mass spectrometry.

DG-7 (11,14-dihydroxy-7,20-epoxy-20-O-derivative of ent-kaurene diterpenoid) is a novel anti-tumor candidate drug. A sensitive and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the quantification of DG-7 in rat plasma. An aliquot of 50 μL plasma sample was prepared by liquid-liquid extraction with ethyl acetate. Chromatographic separation was accomplished on a Waters XTerra C18 column (2.1 mm × 150 mm, 5 μm) with an isocratic elution system consisting of methanol and water. Detection was performed by multiple reaction monitoring (MRM) mode using electrospray ionization in the positive ion mode. The optimized fragmentation transitions for MRM were m/z 590.1→m/z 260.0 for DG-7 and m/z 180.3→m/z 110.1 for phenacetin (internal standard). The method was linear over the concentration range of 5-2,500 ng/mL. The intra- and inter-day precisions were less than 7.9% and the accuracy was within ± 9.0%. The mean recovery of DG-7 ranged from 76.8% to 79.2%. The validated method has been successfully applied to a pharmacokinetic study in rats after intravenous administration of DG-7.

Comparative plant sphingolipidomic reveals specific lipids in seeds and oil

Plant sphingolipids are a highly diverse family of structural and signal lipids. Owing to their chemical diversity and complexity, a powerful analytical method was required to identify and quantify a large number of individual molecules with a high degree of structural accuracy. By using ultra-performance liquid chromatography with a single elution system coupled to electrospray ionization tandem mass spectrometry (UPLC–ESI-MS/MS) in the positive multiple reaction monitoring (MRM) mode, detailed sphingolipid composition was analyzed in various tissues of two Brassicaceae species Arabidopsis thaliana and Camelina sativa. A total of 300 molecular species were identified defining nine classes of sphingolipids, including Cers, hCers, Glcs and GIPCs. High-resolution mass spectrometry identified sphingolipids including amino- and N-acylated-GIPCs. The comparative analysis of seedling, seed and oil sphingolipids showed tissue specific distribution suggesting metabolic channeling and compartmentalization

Simultaneous Determination of 16 Organic Acids in Food by Online Enrichment Ion Chromatography−Mass Spectrometry

A novel analytical method for simultaneous determination of 16 organic acids in foodstuff using online enrichment ion chromatography−mass spectrometry (IC–MS) was developed. The online enrichment and separation of the organic acids were performed using ion chromatography with a homemade enrichment column and a homemade separation column. The qualitative and quantitative analyses of the organic acids were performed using mass spectrometry in the selected ion monitoring (SIM) mode and atmospheric pressure chemical ionization (APCI) source in a negative mode. Two hundred-microliter samples were injected for analysis using an online enrichment time of 3 min. Sodium hydroxide solution (NaOH) was used for the gradient elution system. The two columns made it possible to have a low limit of detection since it has good enriching and separating capabilities. Sixteen kinds of organic acids were separated completely within 30 min. All the curves showed good linearity (R 2 ≥ 0.9949) within the test ranges. The limits of detection (LODs) were between 0.01 and 0.22 mg/L, and the average recoveries were between 80.5 and 109.8 %. The relative standard deviations (RSDs) were less than 8.02 %. The results indicated that this method was simple, rapid, sensitive, and accurate for the determination of organic acids in various food products.

Percutaneous Coronary Intervention in Patients With Diabetes

Patients with diabetes and coronary artery disease represent a challenging and growing subset of the population. Although surgical revascularization is the preferred treatment for patients with diabetes and multivessel coronary artery disease with stable angina, a significant proportion of diabetic patients undergo percutaneous revascularization due to comorbidities, presence of single-vessel disease, or presentation with myocardial infarction. The development of drug-eluting stents has significantly improved the results of percutaneous revascularization among diabetic patients, but a number of challenges remain, including higher rates of restenosis and stent thrombosis among diabetic patients. With current technologies, the outcomes of diabetic patients treated with noninsulin agents have approached that of nondiabetic patients. In comparison, patients with diabetes who require insulin therapy represent a high-risk cohort with increased rates of target vessel failure after coronary revascularization. The development of bioresorbable stents and new drug elution systems may provide additional future benefit among patients with diabetes undergoing percutaneous coronary artery revascularization.

Determination of Metabolism of Neohesperidin by Human Intestinal Bacteria by UPLC-Q-TOF/MS

Neohesperidin as the major isoflavonoid in Aurantii Fructus has been investigated intensively. However, the route and metabolites of neohesperidin by human intestinal bacteria are not well understood and its metabolites may accumulate and exert physiological effects. In this work, 5 strains including Clostridium sp.8, Bacteroides sp.15, Bacillus sp.46, and Enterobacter sp.41-1 and sp.73 were isolated and their abilities to convert neohesperidin were studied. Human fecal microflora were prepared from a healthy Chinese woman and then anaerobically incubated with neohesperidin sample at 37 °C for 48 h. A rapid and simple liquid–liquid extraction method was used for sample pretreatment. A highly sensitive and specific ultra performance liquid chromatography/quadrupole time-of-flight mass spectrometry with MetaboLynx™ method has been developed for the analysis of neohesperidin and related metabolites in the reaction samples. The chromatographic separation was performed on a 1.7 μm particle size Syncronis C18 column using gradient elution system. The components in the extract were identified and confirmed according to the mass spectrometric fragmention mechanisms, MS/MS fragment ions and relevant literature by means of electrospray ionization mass spectrometry in negative ion mode. With this method, a total of five metabolites were detected, the results indicated that hydrolysis, dehydroxylation, demethylation and acetylation were the major metabolism of neohesperidin. The present study provided important information about the metabolism of neohesperidin which will be helpful for fully understanding the impact of the intestinal bacteria on this active component. Furthermore, this work demonstrated the potential of the ultra performance liquid chromatography/quadrupole time-of-flight mass spectrometry approach using MetaboLynx™ for quite rapid, simple, reliable and automated identification of metabolites of natural product.

Preliminary identification of the absorbed bioactive components and metabolites in rat plasma after oral administration of Shaoyao-Gancao decoction by ultra-performance liquid chromatography with electrospray ionization tandem mass spectrometry.

Background:Shaoyao-Gancao decoction (SGD), a traditional Chinese medicine formula, has been used for the treatment of abdominal pain and dysmenorrhea disease in Asia over long period of time. Its effectiveness has been confirmed in clinic, but its active constituents remain unclear.Materials and methods:In this paper, a rapid, sensitive and reliable ultra-performance liquid chromatography-electrospray ionization/quadrupole-time-of-flight high-definition mass spectrometry (UPLC-ESI-Q-TOF-MS) in positive and negative ion mode were established to characterize the active constituents of SGD in vitro. The analysis was performed on a Waters UPLCTM HSS T3 (2.1 × 100 mm, 1.8 µm) using gradient elution system. Automated MetaboLynxTM technique was employed to screen for the potentially bioactive components in rat plasma after oral administration of SGD. MS/MS fragmentation behavior was proposed for aiding the structural identification of the components.Results:Based on the developed method of fingerprint analysis, an injection run of the plasma sample was finished in 15.0 min. A total of 12 compounds including 9 prototype components such as gallicacid, albiflorin, liquiritin, pallidiflorin, liquiritigenin, isoLiquiritigenin, formononetin, isolicoflavonol, licoricone, C9H10O3 and 2 metabolites such as liquiritigenin-4’-O-glucuronide, formononetin glucuronide were identified or tentatively characterized. Of note, 3 ingredients were identified from Radix Paeoniae Alba, and 9 were from Radix Glycyrrhizae.Conclusion:The compounds found in dosed plasma could be the effective substances of SGT for treating dysmenorrheal, and may provide important experimental data for further pharmacological and clinical research of SGD. Furthermore, this work has demonstrated that the feasibility of the UPLC-ESI-Q-TOF-MS for rapid and reliable characterization of identification and structural elucidation of the chemical constituents and their metabolites from herbal medicines.

Determination and characterization of metabolites of scutellarin produced by human intestinal bacteria using UPLC-Q-TOF/MS

To investigate the metabolism of scutellarin by intestinal bacteria in vitro, two strains of bacteria including Bacteroides sp. 21 and Veillonella sp. 10 were isolated from a human intestinal bacterial mixture and studied for their abilities to transform scutellarin into various metabolites. A highly sensitive and specific ultra performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) with MetaboLynx™ software combined with the mass defect filtering (MDF) method provided high throughput capabilities for drug metabolism studies. Four metabolites were isolated using a 1.7 μm particle size Syncronis C 18 column using a gradient elution system and identified according to the mass fragmental mechanism, MS/MS fragment ions and relevant literature. The results of this study indicated that the metabolites of scutellarin were mainly in methylated and aglycone forms.

Simultaneous determination of 16 organic acids in feed additives by on-line enrichment and ion chromatography-mass spectrometry

A novel analytical method for simultaneous determination of sixteen organic acids by on-line enrichment and ion chromatography-mass spectrometry (IC-MS) was developed. Online enrichment and separation of the organic acids were performed by ion chromatography on a homemade enrichment column and a homemade separation column. The qualitative and quantitative analyses of the organic acids were performed by mass spectrometry in selected ion monitoring (SIM) mode on the basis of atmospheric pressure chemical ionization (APCI) source in negative mode. The sample of 200 microL was injected for the analysis, and the on-line enrichment time was 3 min. The sodium hydroxide solution was used as a gradient elution system. The two columns made it possible to have a low limit of detection due to the good enrichment and separation capability. The sixteen organic acids were separated completely within 30 min. All curves showed good linearity within the test concentration ranges. The limits of detection (LODs) were between 0.01 and 0.22 mg/L, and the average recoveries were between 70.6% and 110.8%. The relative standard deviations (RSDs) were less than 6.3%. The results indicate that this method is simple, rapid, sensitive and accurate for the determination of the organic acids in feed additives.

Simultaneous determination of four neuroprotective compounds of Tilia amurensis by high performance liquid chromatography coupled with diode array detector.

Background:Tilia amurensis consists of various compounds, such as flavonoids and terpenoids.Objective:A simple and reliable high performance liquid chromatography (HPLC) coupled with the diode array detector (DAD) method has been established for simultaneous determination of epicatechin, nudiposide, lyoniside, and scopoletin isolated from Tilia amurensis.Materials and Methods:Optimum separations were obtained with a SHISEIDO C18 column by gradient eluton, with 0.1% Trifluoroacetic acid (TFA) water-methanol as the mobile phase. The gradient elution system was completed within 40 minutes. The flow rate and detection wavelength were 1 mL/minute, 205 nm, 250 nm, and 280 nm, respectively.Results:Validation of the analytical method was evaluated by linearity, precision, and the accuracy test. The calibration curve was linear over the established range with R2 > 0.997. The limit of detection (LOD) and limit of quantification (LOQ) ranged from 0.01-15.20 μg/mL and 0.03-46.06 μg/mL. The method exhibited an intraday and interday precision range of 96.25-105.66% and 93.52-109.92%, respectively (RSD <2.80%). The recoveries and relative standard deviation (RSD) of the four compounds in Tilia amurensis were in the range of 90.42-104.84% and 0.2-2.58%.Conclusion:This developed method was accurate and reliable for the quality evaluation of the four compounds isolated from Tilia amurensis.

An improved ultra-performance liquid chromatography-electrospray ionization/quadrupole-time-of-flight high-definition mass spectrometry method for determining ingredients of herbal Fructus corni in blood samples.

Background:Fructus Corni (FC), a well-known traditional Chinese medicine (TCM), derived from the dry ripe sarcocarp of Cornus officinalis Sieb. et Zucc (Cornaceae), has been widely prescribed to treat disease in China for centuries. It has attracted increasingly much attention as one of the most popular and valuable herbal medicine in clinic. However, the systematic analysis of the chemical constituents of FC is difficult to determine and remain unclear.Materials and Methods:In this work, a rapid, sensitive, and reliable ultra-performance liquid chromatography-electrospray ionization/quadrupole-time-of-flight high-definition mass spectrometry (UPLC-ESI/QTOF/MS) with automated data analysis (MetaboLynx™) in negative ion mode were established to characterize the chemical constituents of FC and simultaneously identify components in blood after oral administration of FC, respectively. The analysis was performed on a Waters UPLC™ HSS T3 (2.1 × 100 mm, 1.8 μm) using gradient elution system. MS/MS fragmentation behaviors were proposed for aiding the structural identification of the components.Results:With optimized conditions, a total of 34 peaks were obtained from FC, 23 of which were tentatively characterized by comparing the retention time and mass spectrometry data and retrieving the reference literatures. Of note, the 25 compounds were identified after oral administration of FC, which might be the potential active components in vivo.Conclusion:The present study demonstrates the potential of UPLC-ESI/QTOF/MS approach for the rapid and reliable characterization of the metabolites of natural products.