Defect Filtering Research Articles

Comprehensive metabolism study of swertiamarin in rats using ultra high-performance liquid chromatography coupled with Quadrupole-Exactive Orbitrap mass spectrometry

Swertiamarin, a natural ingredient with potent pharmacological activities in the iridoid glycoside family, had been reported to have significant therapeutic effects on a variety of human diseases. In this study, a systematic and efficient strategy based on UHPLC-Q-Exactive Orbitrap mass spectrometry was established to reveal the metabolic profile of swertiamarin in rat urine, plasma, and faeces. First of all, post-acquisition data-mining methods, including multiple mass defect filters (MMDFs) and high-resolution extracted ion chromatograms (HREICs), were developed to screen the metabolite candidates of swertiamarin from the complete mass scan data sets. Second, according to the diagnostic product ions (DPIs), neutral loss fragments (NLFs), chromatographic retention time, accurate mass measurement and calculated Clog P values, all metabolite candidates were rapidly identified. As a consequence, 49 metabolites altogether, including archetype compound, were preliminarily characterised. The corresponding in vivo biotransformation processes, such as dehydration, dehydrogenation, hydroxylation, hydrogenation, methylation, sulphonation, N-acetylcysteine (NAC) formation, N-heterocyclisation and their composite reactions, were all discovered in the study. In conclusion, our results not only detailedly elucidated many new metabolites and metabolic pathways of swertiamarin, but also provided a reference for further study of its pharmacological mechanism and evaluation of its safety.

A comprehensive profiling and identification of liquiritin metabolites in rats using ultra-high-performance liquid chromatography coupled with linear ion trap–orbitrap mass spectrometer

Liquiritin (LQ), a main component of liquorice, exerts various biological activities. However, insufficient attentions have been paid to the metabolism study on this natural compound until now. Our present study was conducted to investigate the LQ metabolites in rats urine, faeces and plasma using UHPLC-LTQ-Orbitrap mass spectrometer in both positive and negative ion modes. Meanwhile, post-acquisition data-mining methods including high-resolution extracted ion chromatogram (HREIC), multiple mass defect filters (MMDFs), neutral loss fragments (NLFs) and diagnostic product ions (DPIs) were utilised to screen and identify LQ metabolites from HR-ESI-MS to ESI-MS n stage. As a result, a total of 49 metabolites were detected and characterised unambiguously or tentatively. These metabolites were presumed to generate through glucuronidation, sulfation, deglucosylation, dehydrogenation, methylation, hydrogenation, hydroxylation, ring cleavage and their composite reactions. Our results not only provided novel and useful data to better understand the biological activities of LQ, but also indicated that the proposed strategy was reliable for a rapid discovery and identification drug-related constituents in vivo.

Development of a UHPLC-MS/MS-based data-mining method for rapid profiling and characterization of magnolol metabolites in rat urine and plasma

Magnolol, an essential bioactive natural lignans isolated from Magnolia Officinalis, has various pharmacological activities, such as antibacterial, anti-inflammatory, antioxidation and anti-tumor. In this study, a practical strategy based on ultra-high-performance liquid chromatography coupled with linear ion trap-Orbitrap mass spectrometry (UHPLC-LTQ-Orbitrap MS) was established to reveal the metabolic fate of magnolol in rat plasma and urine. First of all, in the data-dependent scanning (DDS) acquisition mode, the ESI-MSn data sets of biological samples and reference standard were obtained by using a high-quality online data analysis method. Subsequently, off-line data-mining techniques including multiple mass defect filters (MMDFs) and high-resolution extracted ion chromatograms (HREICs) were applied to screen major-to-trace metabolites of magnolol at the full-scan ESI-MS1 level. Finally, a total of 177 metabolites (prototype compound included) were preliminarily observed and characterized according to accurate mass measurement, the characteristic fragmentation patterns, chromato-graphic behaviors, and corresponding Clog P values. The results showed that magnolol experienced a variety of biotransformation reactions in rats, including hydroxylation, methoxylation, dehydrogenation, carboxylation, sulfonation, glucuronide conjugation, glucose conjugation, N-acetylcysteine (NAC) conjugation, glutathione conjugation and their composite reactions. In conclusion, this study not only greatly expanded the understanding of the therapeutic material basis and pharmacological mechanism of magnolol, but also provided new ideas for its toxicity evaluation, safety monitoring and drug delivery forms design.

Direct Heteroepitaxy and Selective Area Growth of GaP and GaAs on Si by Hydride Vapor Phase Epitaxy

Direct heteroepitaxy and selective area growth (SAG) of GaP and GaAs on Si(100) and Si(111) are implemented by low‐pressure hydride vapor phase epitaxy (LP‐HVPE), which are facilitated by buffer layers grown at 410–490 °C with reactive gas mixing directly above Si substrates. High‐density islands observed on GaP buffer layers on Si result in rough morphology and defect formation in the subsequent GaP layers grown at 715 °C. The impact of growth temperature of GaAs buffer layers on the crystal quality of GaAs/Si is studied. A decreased nucleation temperature significantly improves the morphology and crystalline quality of the overall GaAs growth on Si. It is observed that Si(111) substrates are favorable for both GaP and GaAs growths in comparison with Si(100). In SAGs of GaP/Si and GaAs/Si, the high selectivity innate to HVPE is maintained in the used unconventional growth regime. The spatially resolved photoluminescence mapping reveals the material quality of GaAs/Si is enhanced by defect filtering by SAG. The outcomes of this work will pave the way of III–V/Si integration realized by cost‐effective HVPE for photonic device applications.

Identification of metabolites of Zhali Nusi Prescription in rat plasma, bile, urine and feces after oral administration

This study was designed to determine the metabolites of Zhali Nusi Prescription(ZLNSP) in rats. The ultra-high performance liquid chromatography-LTQ Orbitrap mass spectrometric(UHPLC-LTQ-Orbitrap-MS) and mass defect filter techniques were applied to analyze the metabolites of ZLNSP in rat plasma, bile, urine and feces. The biological samples were analyzed by ACQUITY UPLC BEH T_3 column(2.1 mm×100 mm,1.7 μm), with 0.1% formic acid water(A)-acetonitrile(B) as mobile phase, and the biological samples were analyzed in negative ion mode by electrospray ionization mass spectrometry(ESI-MS). An analytical method for biological samples of rats was established, and 8 prototype components and 36 metabolites were identified. The results showed that the metabolic pathways of the main components of ZLNSP in rats included methylation, glucuronidation, sulfation and so on. It provi-ded information for the therapeutic effect of ZLNSP in vivo.

Metabolic Profile of Dendrobine in Rats Determined by Ultra-high-performance Liquid Chromatography/Quadrupole Time-of-flight Mass Spectrometry.

Dendrobine is a major alkaloid present mainly in dendrobium nobile Lindl. It has been reported to have analgesic, antipyretic, lower heart rate and blood pressure and other pharmacologic activities. Despite its critical pharmacological function, its metabolite profiling is still unclear. In this study, the in vivo metabolite profiling of dendrobine in rats was investigated using ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UPLC/Q-TOF-MS). The metabolites were predicted using MetabolitePilotTM software with a mass defect filter (MDF) technique. These predicted metabolites were further analyzed by MS2 spectra and compared with the detailed fragmentation pathway of the dendrobine standard and literature data. Total of 59 metabolites were identified for the first time in rat plasma and urine after oral administration of dendrobine. Demethylated, dehydrogenated, hydroxylated, ketonizated and glucuronide were the major metabolic pathways. This research provides scientific and reliable support for full understanding of the metabolic fate of dendrobine in vivo.

InGaSb Defect Filter Layer to Improve Performance of GaSb Solar Cells Grown on GaAs Substrates

The reduction of the threading dislocation density in metamorphic GaSb grown on GaAs substrates through the use of InGaSb defect filter layers has been investigated. More specifically, we study the effects of strain and thickness on the ability of a InGaSb defect filter layer to reduce threading dislocations in GaSb solar cells grown on GaAs substrates. The strain between the GaSb metamorphic layer on GaAs substrate (99.5% relaxed) and the InGaSb defect filter layer is varied by changing the indium composition in the InGaSb layer. It is demonstrated that an InGaSb defect filter layer with 0.6% strain is more effective for blocking threading dislocations compared with higher-strain layers, resulting in improved short-circuit current (Jsc) and open-circuit voltage (Voc) for the metamorphic GaSb solar cell. The optimization of the defect filter layer involves varying the thickness of the layer to achieve the lowest possible threading dislocation density. This also takes into account the critical thickness of the InGaSb layer on GaSb to avoid generation of threading dislocations from the InGaSb layer itself. It is shown that adding an In0.11Ga0.89Sb defect filter layer with thickness of 250 nm and 0.6% strain beneath a GaSb solar cell grown on a GaAs substrate improves Voc from 0.1 V to 0.16 V and Jsc from 19.7 mA/cm2 to 24.7 mA/cm2.

Metabolic profiling of coumarins by the combination of UPLC-MS-based metabolomics and multiple mass defect filter

Coumarins have aroused high interests due to their diverse bioactivities. Understanding of its metabolism contributes to determine the druggability of coumarin in vivo.A sensitive and efficient strategy based on ultra-performance liquid chromatography-mass spectrometer (UPLC-MS) analysis combined with various data-processing techniques including metabolomics and multiple mass defect filter (MMDF) was established for the comprehensive screening and elucidation of potential coumarin metabolites.Total 20 metabolites of scoparone were identified in this study, including 14 undescribed metabolites. The metabolism of two other similar coumarins scopoletin and esculetin also could be determined using this strategy.By the established strategy, this study gives the insights about the major metabolic pathways of scoparone in vivo and in vitro metabolism, including demethylation, hydroxylation, hydration, cysteine conjugation, glucuronide conjugation and sulfate conjugation. Additionally, the metabolic pathways of scopoletin and esculetin were determined as hydroxylation, glucuronidation and sulfation. These results contribute to the understanding of metabolic characterization of coumarins, and demonstrate that the combination of UPLC-MS-based metabolomics and MMDF is a powerful approach to determine the metabolic pathways of coumarin compounds.

Data Mining to Determine the Influence of Fluid Properties on the Integrity Test Values.

Eudralex volume 4, Annex 1, the European Union Good Manufacturing Practice for sterile products, requires that "The integrity of the sterilised filter should be verified before use" (1). Implicit in this requirement for a PUPSIT is the rationale that the sterilizing filter could sustain damage during sterilization or use (i.e., subsequent to any pre-use test conducted prior to sterilization), causing a defect which would not be detected by the post-use integrity ("masked" during filtration). To assess whether a filter defect could be masked by partial filter plugging, we evaluated the impact of the bacterial challenge test (BCT) on the bubble point (BP) of the test filters. The BP tests that are conducted before and after the BCT have been collected and compared for 2086 filters (1571 × test filters and 515 × control filters), representing 531 BCTs on 518 different pharmaceutical products, buffers, and in-process fluids. These tests comprise a cross section of fluids from multiple firms spanning the pharmaceutical and biotechnology industry. A posttest to pretest BP ratio was calculated for each filter and the distribution of these ratios examined to determine whether there were cases of elevation of the BP because of bacterial loading to the point where masking of a filter defect could occur; that is, if a defective filter could pass integrity testing due to apparent reduction in filter pore size because of the bacteria retained during the BCT. Ratios were averaged across all tests for the same test fluid. The mean average ratio was 1.00 ± 0.15, indicating that on the average, elevation of the BP does not occur. To assess the risk of masking a filter defect, observed BP ratios were compared to the ratio of the minimum BP specification of a 0.2 μm filter to that of a 0.45 μm filter of the same membrane type. The lowest such ratio for any membrane type was 1.33. A BP ratio equal to or higher than this ratio was considered a risk for masking, because a 0.45 μm filter could appear to meet the specifications of a 0.2 μm filter. Out of 518 average BP ratios, only eight fluids (1.5%) produced BP ratios meeting this criterion for a masking risk. Potential risk factors associated with these cases are discussed. We conclude that filtration processes producing BP changes sufficient to present a risk of masking defects are not common, and are detectable during the routine BCT. The BP ratios observed during routine BCT are one means to assess the potential of a given filtration process to mask defects and can be considered when determining whether a PUPSIT should be implemented.

Rapid detection and structural characterization of verapamil metabolites in rats by UPLC-MSE and UNIFI platform.

High-resolution mass spectrometry (HRMS) is an important technology for studying biotransformations of drugs in biological systems. In order to process complex HRMS data, bioinformatics, including data-mining techniques for identifying drug metabolites from liquid chromatography/high-resolution mass spectrometry (LC/HRMS) or multistage mass spectrometry (MSn ) datasets as well as elucidating the detected metabolites' structure by spectral interpretation software, are important tools. Data-mining technologies have widely been used in drug metabolite identification, including mass defect filters, product ion filters, neutral-loss filters, control sample comparisons and extracted ion chromatographic analysis. However, the metabolites identified by current different technologies are not the same, indicating the importance of technique integration for efficient and complete identification of metabolic products. In this study, a universal, high-throughput workflow for identifying and verifying metabolites by applying the drug metabolite identification software UNIFI is reported, to study the biotransformation of verapamil in rats. A total of 71 verapamil metabolites were found in rat plasma, urine and faeces, including two metabolites that have not been reported in the literature. Phase I metabolites of verapamil were identified as N-demethylation, O-demethylation, N-dealkylation and oxidation and dehydrogenation metabolites; phase II metabolites were mainly glucuronidation and sulfate conjugates, indicating that UNIFI software could be effective and valuable in identifying drug metabolites.

Capsaicin metabolites and GSH-associated detoxification and biotransformation pathways in human liver microsomes revealed by LC-HRMS/MS with data-mining tools

Capsaicin (CAP) is a principal pungent ingredient in hot peppers, it is also employed as a common food additive, an efficient pharmaceutical component, or even a riot control agent. CAP exerts various pharmacological activities as well as associated adverse physiological responses and causes moderate toxicity if overused. A full screening and identification of CAP metabolites in combination with its main detoxification pathways are crucial for the clear demonstration on its pharmacological and toxicological significance. Here, we employed a post-acquisition data-mining metabolic screening approach to rapidly find and identify a broad range of CAP metabolites generated from in vitro human liver microsomes, based on an ultra-performance liquid chromatography-quadrupole orbitrap high resolution tandem mass spectrometric method. First, we collected full scan MS and MS/MS data sets by a data-dependent acquisition method in positive ion mode, and then we employed a modified mass defect filter and a diagnostic ion filter to screen and identify all the probable CAP metabolites, combining with information including retention time, accurate mass, characteristic fragments, and relevant drug biotransformation patterns. In comparison with the stable isotope-labeled CAP involved biotransformation products, we confirmed 19 functionalized metabolites and 13 glutathione (GSH) conjugates of CAP, in which 13 metabolites are reported for the first time. We then briefly depicted an overview metabolic pathway of CAP from the GSH detoxification viewpoint, revealed that various metabolites of CAP can be generated from single or multiple biotransformation and metabolic reactions. Both CAP and its reactive metabolites produced relevant GSH conjugates, which indicates a wide and important detoxification value of GSH conjugation way.

Characterization of the metabolite of AdipoRon in rat and human liver microsomes by ultra-high-performance liquid chromatography combined with Q-Exactive Orbitrap tandem mass spectrometry.

AdipoRon is an orally active adiponectin receptor agonist. The aim of this study was to characterize the metabolites of AdipoRon in rat and human liver microsomes using ultra-high performance liquid chromatography combined with Q-Exactive Orbitrap tandem mass spectrometry (UPLC-Q-Exactive-Orbitrap-MS) together with data processing techniques including extracted ion chromatograms and a mass defect filter. AdipoRon (10 μm) was incubated with liver microsomes in the presence of NADPH and this resulted in a total of 11 metabolites being detected. The identities of these metabolites were characterized by comparing their accurate masses and fragment ions as well as their retention times with those of AdipoRon using MetWorks software. Metabolites M1-M3, M6, and M8-M11 were identified for the first time. Metabolite M4, the major metabolite both in rat and human liver microsomes, was further confirmed using the reference standard. Our results revealed that the metabolic pathways of AdipoRon in liver microsomes were N-dealkylation (M2), hydroxylation (M, M5-M9), carbonyl reduction (M4) and the formation of amide (M10 and M11). Our results provide valuable information about the in vitro metabolism of AdipoRon, which would be helpful for us to understand the mechanism of the elimination of AdipoRon and, in turn, its effectiveness and toxicity.

Characterization of ginsenoside compound K metabolites in rat urine and feces by ultra-performance liquid chromatography with electrospray ionization quadrupole time-of-flight tandem mass spectrometry.

Ginsenoside compound K (CK) is an active metabolite of ginsenoside and has been shown to have ameliorative property in various diseases. However, the detailed in vivo metabolism of this compound has rarely been reported. In the present study, a method using liquid chromatography quadrupole time-of-flight tandem mass spectrometry together with multiple data processing techniques, including extracted ion chromatogram, multiple mass defect filter and MS/MS scanning, was developed to detect and characterize the metabolites of CK in rat urine and feces. After oral administration of CK at a dose of 50 mg/kg, urine and feces were collected for a period of time and subjected to a series of pretreatment. A total of 12 metabolites were tentatively or conclusively identified, comprising 11 phase I metabolites and a phase II metabolite. Metabolic pathwaysof CK has been proposed, including oxidation, deglycosylation, deglycosylation with sequential oxidation and dehydrogenation and deglycosylation with sequential glucuronidation. Relative quantitative analyses suggested that deglycosylation was the main metabolic pathway. The result could offer insights for better understanding of the mechanism of its pharmacological activities.

Metabolites study on 5-O-methylvisammioside in vivo and in vitro by ultra high performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry.

5-O-Methylvisammioside is one of major chromones of Radix Saposhnikoviae possessing definite pharmacological activities, but there are few reports with respect to the metabolism of 5-O-methylvisammioside. In this work, metabolites in vivo were explored in male Sprague-Dawley rats and in vitro investigated on rat intestinal bacteria incubation model and were identified by using ultra high performance liquid chromatography/quadrupole time-of-flight mass spectrometry. An online data acquisition method based on a multiple mass defect filter and dynamic background subtraction was developed to trace all probable metabolites. As a result, 26 metabolites in vivo (including 18, 15, 10, and 10 in rat urine, faece, bile, and blood) and 7 metabolites in vitro were characterized, respectively. Additionally, the main metabolic pathways in vivo and in vitro, including deglycosylation, deglycosylation + demethylation, deglycosylation + oxidation, N-acetylation, and sulfate conjugation, were summarized by calculating the relative content of each metabolite. The obtained results significantly enriched our knowledge about 5-O-methylvisammioside metabolism and will lead to a better understanding of its safety and efficacy.

Comprehensive metabolism study of polydatin in rat plasma and urine using ultra-high performance liquid chromatography coupled with high-resolution mass spectrometry

Polydatin is one of the main bioactive constituents isolated from Polygonum cuspidatum Sieb. et Zucc., which possesses various pharmacological activities. In this study, we established an efficient strategy based on ultra-high performance liquid chromatography coupled with high-resolution mass spectrometry to uncover polydatin metabolites in rat urine and plasma. Firstly, multiple mass defect filters (MMDFs) combined with high-resolution extracted ion chromatograms (HREICs) was utilized to perform post-acquisition data-mining in ESI-MS1 stage. Secondly, metabolite candidates of polydatin were expounded systematically on the basis of diagnostic product ions (DPIs), chromatographic retention times, accurate mass, and neutral loss fragments (NLFs). Consequently, a total of 41 metabolites (polydatin included) were detected and identified tentatively in 12 min. These metabolites, including 40 in rat urine and 7 in rat plasma, were presumed to generate through glucuronidation, sulfation, deglucosylation, dehydrogenation, methylation, hydrogenation, hydroxylation and their composite reactions. Meanwhile, metabolite clusters, which were set in the form radially, were found in this study. In conclusion, our study expounded polydatin metabolites in rats and provided a reference for further researches on therapeutic material basis and mechanism of polydatin.

Mechanisms for the Time‐dependent Inhibition of the Human Nicotine‐metabolizing Enzyme CYP2A6 by Cinnamaldehyde: Evidence for Formyl Hydrogen Abstraction and Heme Degradation

trans‐Cinnamaldehyde (CA) was previously shown to selectively inhibit cytochrome P450 2A6‐mediated metabolism through heme destruction without modification of the apoprotein. The goal of this study was to further investigate factors that influence the mechanism and potency of inhibition. Hydrogen atom abstraction was evaluated by measuring how the CYP2A6 inactivation rate (kinact) changed when protium atoms (1H) were selectively replaced with deuterium atoms (2H) at three different carbons (carbonyl, alpha, and beta) in CA. The structure‐inhibitor relationship for CA analogs was advanced by evaluating how substituents at the ortho position influenced CYP2A6 inactivation rates, in a recombinant system using coumarin hydroxylase as a reporter of 2A6 activity. Metabolite identification was conducted since it is an indirect indicator of substrate orientation in the enzyme active site, and can provide clues about reaction routes that lead to inactivation. Heme analysis and metabolite identification studies used a reconstituted system with purified human 2A6 and rat reductase, and a QTOF mass spectrometer incorporating a mass defect filter for detection. 2H incorporation at the formyl position demonstrably slowed the rate of inactivation (kinact = 0.043 min−1 +/− 0.001; p < 0.00002; remaining activity = 17.1 +/− 0.6 and 10.5 +/− 0.4 pmol/min/pmol for 2H‐CA and 1H‐CA, respectively). The kinact for the alpha‐ and beta‐2H‐labeled CA did not differ from 1H‐CA (0.058 +/− 0.004, 0.060 +/− 0.006, and 0.061 +/− 0.002 min−1, respectively). Also, kinact decreased as a function of the 2H‐CA/1H‐CA ratio. Mass defect filtering (range = 0.01–0.06 Da) revealed that the primary product from CYP2A6‐mediated metabolism of 1H‐CA and 2H‐CA is cinnamic acid. Metabolites from epoxidation and aromatic hydroxylation were not observed. The relative peak area of cinnamic acid decreased 29% (n=5; p=0.025) for 2H‐CA compared to 1H‐CA. Electron withdrawing groups substantially increased kinact: CA (0.039 min−1), nitro‐CA (0.223 min−1), trifluoromethyl‐CA (0.142 min−1) and difluoro‐CA (0.244 min−1). Substitution with an electron donating group (methyl) resulted in complete disappearance of time dependent inhibition. Thus, both resonance and inductive effects have a significant role in inactivation. No heme adducts were detected using mass defect filtering, suggesting adduct instability compared to positive controls (aminobenzotriazole). Together the results support the hypothesis that the formyl proton is abstracted during inactivation and the potency of CA analogs can be substantially enhanced by structural changes that stabilize the radical.Support or Funding InformationResearch reported in this presentation was supported by the National Institute On Drug Abuse of the National Institutes of Health under Award Number 15DA042341. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Mass defect filtering for suspect screening of halogenated environmental chemicals: A case study of chlorinated organophosphate flame retardants.

Organophosphate flame retardants (OPFRs) are a class of flame retardants widely found in environmental and biological matrices that have been extensively studied due to their adverse health effects in humans. OPFRs are loosely bound chemicals that can detach from treated products and be released into indoor and outdoor environments, where they have the potential to further undergo transformation and degradation processes, in particular the chlorinated OPFRs (Cl-PFRs). Their detection remains a moving target for analysts, and traditional targeted mass spectrometry methods are suitable only for those compounds with authentic standards. Mass defect filter (MDF) is a strategy to filter molecular features using thresholds applied to the mass defect value of a target ion or molecular feature of interest. We have developed an MDF strategy for the detection and tentative identification of twelve potential Cl-PFR transformation products in a study mixture of six known Cl-PFRs using MS/MS data acquired on a high-resolution mass spectrometer. Most compounds in the Cl-PFRs family share a ClO4 P group as a core structure, of which modification results in a significant shift in the exact masses of the resulting compounds but show only a minimal shift in their mass defects. Subsequently, the MDF strategy was employed to tentatively identify Cl-PFRs retrospectively in six human urine samples that had previously been analyzed. MDF in combination with product ion filtering for the characteristic [H2 O3 P]+ and [H4 O4 P]+ ions and neutral loss filtering for the characteristic Cn H2n-x Clx group resulted in revealing suspects and homologues in the Cl-PFRs family. Furthermore, the MDF of the product ions detected additional Cl-PFR-related compounds that differed significantly in the exact masses of both precursor and product ions but had minimal shift in the mass defects of product ions. The mass defect of one or more common product ions helped to detect a few Cl-PFR analogs that had not been identified by MDF of the core structure precursor ion. MDF helped to detect some Cl-PFRs present in lower concentrations, which went undetected without data filters. MDF also helped to detect chromatographic peaks for Cl-PFR homologues that are likely structural analogs that resulted from impurities and/or derivatives and transformation products. The methodology was applied to demonstrate and tentatively detect known and suspect Cl-PFRs in human urine samples retrospectively.

Yield Improvement in Color Filter Manufacturing Using Taguchi Methods and TRIZ’s Substance–Field Analysis

Thin-film transistor liquid crystal display (TFT-LCD) has been widely applied to electronic merchandise in daily lives. All panel makers are trying every possible way to produce high-quality products to fight for market share. However, the particle issue in the clean room often causes scrapped panel and increased costs. In the past, engineers in factory usually carried out quality improvement via the trial-and-error and empirical method, yet the results were rather poor, which often delayed the schedule of mass production of new product. A problem-solving procedure has been proposed in this paper, and we use a TFT-LCD maker as an example to explain the effectiveness of this procedure. The particle and gel defects in the process critical to quality are defined via the historical data analysis of the case company. The statistical analysis is utilized to screen out the factors with a significant impact on defective color filter (CF), Taguchi methods are used to find out optimal parameters combination, and the substance–field analysis in the Teoriya Resheniya Izobretatelskikh Zadatch (Russian) and 76 standard solutions come up with the optimal improvement plan to verify the effectiveness of improvement. Finally, the obtained improvement plan is standardized, and a relevant operating standard is revised. The results indicate that the process yield of CF has been improved, which has led to a hard saving of more than U.S. $3.7 million.

A High Throughput Three-step Ultra-performance Liquid Chromatography Tandem Mass Spectrometry Method to Study Metabolites of Atractylenolide-III.

Atractylodes macrocephala Koidz (AMK) is a traditional Chinese medicine widely used in the treatment of various diseases, especially spleen deficiency. As the principle active constituents of AMK, however, the metabolites of Atractylenolide-III (A-lactone-III) have not been identified in rats yet. In this study, a three-step high throughput method based on UHPLC-Q-TOF-MS-MS was developed to profile and characterize the metabolites of A-lactone-III in rat feces, urine and plasma. The initial step was a full-scan that utilized a multiple mass defect filter (MMDF) combined with dynamic background subtraction (DBS). PeakView®1.2 and Metabolitepilot™1.5 software was then used to obtain data and seek possible metabolites. Finally, MS-MS spectra of the parent drug and possible metabolites were compared by the fragment ion peaks and retention times, which enabled metabolites to be identified. As a result, 53 metabolites were characterized in rats in vivo. The metabolic pathways of A-lactone-III were identified as including methylation, oxidation, hydroxylation, dihydroxylation, hydrogenation, glycosylation, sulfonation, and glucuronide, cysteine and N-acetylcysteine conjugation.

Simultaneously targeted and untargeted multicomponent characterization of Erzhi Pill by offline two-dimensional liquid chromatography/quadrupole-Orbitrap mass spectrometry

Large-scale targeted and untargeted metabolites characterization can be achieved by feat of different liquid chromatography/mass spectrometry (LC–MS) platforms by multiple MS experiments or using data-independent acquisition followed by precursor-product ions matching based on certain algorithms. The resulting insufficiency in efficiency and availability greatly restricts the applicability of these strategies in large-scale profiling and identification of various metabolites. A strategy simultaneously enabling both the targeted and untargeted metabolites characterization is established on a Q Exactive hybrid quadrupole-Orbitrap mass spectrometer, by integrating precursor ions list-triggered data-dependent MS2 acquisition (PIL/dd-MS2) of the targeted components and using the “If idle-pick others” (IIPO) function to induce untargeted metabolites fragmentation. A compounds-specific mass defect filter (MDF) algorithm is proposed as a method to generate the PIL. As a proof of concept, this strategy coupled with offline two-dimensional liquid chromatography (2D-LC) was applied to identify the multicomponents of a traditional Chinese medicine formula Erzhi Pill (EZP). A rigid MDF vehicle was elaborated by orthogonal screening of the integer mass and integer mass-dependent dynamic mass defects considering a variation of 20 ppm. The Full MS/dd-MS2 method enabling PIL and IIPO exhibited better performance than Full MS/dd-MS2 and Targeted SIM/dd-MS2 (selected ion monitoring) in respect of the sensitivity in identifying the targeted components and the ability to characterize more untargeted ones. As a consequence, 270 components were separated from EZP, and 146 thereof were selectively characterized. In conclusion, it is a practical, multifaced strategy facilitating the in-depth metabolites profiling and characterization of complex herbal and biological samples.