Performance Liquid Chromatography-tandem Mass Research Articles

Detection of Endocannabinoids and Glucocorticoids in Hair of People Living with HIV by High Performance Liquid Chromatography Tandem Mass Spectrometry

Detection of Endocannabinoids and Glucocorticoids in Hair of People Living with HIV by High Performance Liquid Chromatography Tandem Mass Spectrometry

Determination of Fipronil and Its Metabolites in Paddy fish Soil Using High Performance Liquid Chromatography Tandem Mass Spectrometry

Determination of Fipronil and Its Metabolites in Paddy fish Soil Using High Performance Liquid Chromatography Tandem Mass Spectrometry

Residual Migration and Degradation of Spirodiclofen During Tea Growing, Processing and Brewing by Ultra Performance Liquid Chromatography Tandem Mass Spectrometry

Residual Migration and Degradation of Spirodiclofen During Tea Growing, Processing and Brewing by Ultra Performance Liquid Chromatography Tandem Mass Spectrometry

Serum Untargeted UHPLC-HRMS-Based Lipidomics to Discover the Potential Biomarker of Colorectal Advanced Adenoma.

BackgroundAs a key precancerous lesion, colorectal advanced adenoma (CAA) is closely related to the occurrence and development of colorectal cancer (CRC). Effective identification of CAA-related biomarkers can prevent CRC morbidity and mortality. Lipids, as an important endogenous substance, have been proved to be involved in the occurrence and development of CRC. Lipidomics is an advanced technique that studies lipid metabolism and biomarkers of diseases. However, there are no lipidomics studies based on large serum samples to explore diagnostic biomarkers for CAA.MethodsAn integrated serum lipid profile from 50 normal (NR) and 46 CAA subjects was performed using ultra-high performance liquid chromatography tandem high-resolution mass spectrometry (UHPLC-HRMS). Lipidomic data were acquired for negative and positive ionization modes, respectively. Differential lipids were selected by univariate and multivariate statistics analyses. A receiver operator characteristic curve (ROC) analysis was conducted to evaluate the diagnostic performance of differential lipids.ResultsA total of 53 differential lipids were obtained by combining univariate and multivariate statistical analyses (P < 0.05 and VIP > 1). In addition, 12 differential lipids showed good diagnostic performance (AUC > 0.90) for the discrimination of NR and CAA by receiver operating characteristic curve (ROC) analysis. Of them, the performance of PC 44:5 and PC 35:6e presented the outstanding performance (AUC = 1.00, (95% CI, 1.00–1.00)). Moreover, triglyceride (TAG) had the highest proportion (37.74%) as the major dysregulated lipids in the CAA.ConclusionThis is the first study that profiled serum lipidomics and explored lipid biomarkers with good diagnostic ability of CAA to contribute to the early prevention of CRC. Twelve differential lipids that effectively discriminate between NR and CAA serve as the potential diagnostic markers of CAA. An obvious perturbation of TAG metabolism could be involved in the CAA formation.

Pharmacokinetics of Azalomycin F, a Natural Macrolide Produced by Streptomycete Strains, in Rats.

As antimicrobial resistance has been increasing, new antimicrobial agents are desperately needed. Azalomycin F, a natural polyhydroxy macrolide, presents remarkable antimicrobial activities. To investigate its pharmacokinetic characteristics in rats, the concentrations of azalomycin F contained in biological samples, in vitro, were determined using a validated high-performance liquid chromatography–ultraviolet (HPLC-UV) method, and, in vivo, samples were assayed by an ultra-high performance liquid chromatography–tandem mass spectrometric (UPLC–MS/MS) method. Based on these methods, the pharmacokinetics of azalomycin F were first investigated. Its plasma concentration-time courses and pharmacokinetic parameters in rats were obtained by a non-compartment model for oral (26.4 mg/kg) and intravenous (2.2 mg/kg) administrations. The results indicate that the oral absolute bioavailability of azalomycin F is very low (2.39 ± 1.28%). From combinational analyses of these pharmacokinetic parameters, and of the results of the in-vitro absorption and metabolism experiments, we conclude that azalomycin F is absorbed relatively slowly and with difficulty by the intestinal tract, and subsequently can be rapidly distributed into the tissues and/or intracellular f of rats. Azalomycin F is stable in plasma, whole blood, and the liver, and presents plasma protein binding ratios of more than 90%. Moreover, one of the major elimination routes of azalomycin F is its excretion through bile and feces. Together, the above indicate that azalomycin F is suitable for administration by intravenous injection when used for systemic diseases, while, by oral administration, it can be used in the treatment of diseases of the gastrointestinal tract.

Analysis of the effect of sterilization and storage on the quality of Pinus yunnanensis pollen based on untargeted metabonomics

Pinus yunnanensis pollen has many bioactivity compounds. However, the effect of sterilization and storage on the quality of pine pollen remains unknown. In this study, 36 metabolites, including kaempferol, cetyl betaine, methyl ricinoleate, and naringenin, were tentatively identified in fresh pine pollen (YNS), irradiation sterilized pine pollen (IR), ultra-high temperature instantaneous sterilized pine pollen (UHT), one-year pine pollen (OY) and two-year pine pollen (TY) using untargeted metabolomics based on ultra-high performance liquid chromatography tandem mass spectrometry. Compared with UHT, IR had less effect on pine pollen, and the longer of storage time, the greater effect on pine pollen metabolites. YNS contain more kaempferol and N-(2-hydroxypropyl) methacrylamide, which indicated that they were easily lost during the storage and sterilization. And the other four groups all contained 2-formylpyridine which might be due to contamination during sterilization and storage. Practical applications Metabolomic has been widely used in food research and quality control. The result showed that kaempferol, cetyl betaine, methyl ricinoleate, and naringenin were greatly affected by processing methods, which provided a reference for the storage and sterilization of pine pollen. Additionally, this study supplied application prospects for pine pollen research and quality control in other natural product.

Glycosyl imprinted mesoporous microspheres for the determination of glycopeptide antibiotics using ultra-high performance liquid chromatography coupled with tandem mass spectrometry

Glycopeptide antibiotics are critical weapons against serious Gram-positive resistant bacteria, and therefore the development of analytical methods for their determination is essential. In this work, with the aim of extending the scope of molecularly imprinted mesoporous materials to the recognition of large molecules such as proteins and peptides, we selected the glycosyl moiety of glycopeptide antibiotics as a template and synthesised a boronic acid functional monomer by click chemistry reaction to prepare glycosyl imprinted mesoporous microspheres. On the basis of boronate affinity, the template and the functional monomer formed a self-assembly structure that was incorporated into the silica framework during polymerisation. The removal of the glycosyl moiety created cavities with boronic acid groups covalently anchored to the pore walls of the glycosyl imprinted mesoporous microspheres. The resultant microspheres showed regular spherical shape, narrow size distribution and porous structure and exhibited high adsorption capability and fast adsorption kinetics. The size exclusion effect of the mesoporous structure prevents large molecules from entering the cavities, while the glycosyl imprinted cavities provide selectivity for glycopeptide antibiotics. The glycosyl imprinted mesoporous microspheres were employed to separate six glycopeptide antibiotics in serum samples, which were then determined using ultra-high performance liquid chromatography tandem mass spectrometry. The proposed method exhibited satisfactory linearity in the range of 0.1 to 20.0 μg/L, demonstrating great potential for the determination of glycopeptide antibiotics in serum samples.

Simultaneous determination of multiple isomeric hydroxylated polycyclic aromatic hydrocarbons in urine by using ultra-high performance liquid chromatography tandem mass spectrometry

Monitoring the level of hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) in urine is the key to exploring human metabolic changes and comprehensive potential toxicity of PAHs. The OH-PAHs with isomeric structure have different biological functions, indicating that their quantification is indispensable. However, the quantitation method is still dissatisfactory due to the poor separation of these isomeric OH-PAHs. The current study established a ultra-high performance liquid chromatography (UHPLC) tandem mass spectrometry (MS) method to complete the simultaneous determination of 17 OH-PAHs, including two naphthalene metabolites (1-hydroxynaphthalene, 2-hydroxynaphthalene), two fluorene metabolites (2-hydroxyfluorene, 3-hydroxyfluorene), five phenanthrene metabolites (1-hydroxyphenanthrene, 2-hydroxyphenanthrene, 3-hydroxyphenanthrene, 4-hydroxyphenanthrene, 9-hydroxyphenanthrene), a pyrene metabolite (1-hydroxypyrene), five chrysene metabolites (1-hydroxychrysene, 2-hydroxychrysene, 3-hydroxychrysene, 4-hydroxychrysene, 6-hydroxychrysene) and two benzo[a]pyrene metabolites (3-hydroxybenzo[a]pyrene, 9-hydroxybenzo[a]pyrene). The method validation results showed good selectivity, linearity (r2 > 0.999), inter-day and intra-day precision (relative standard deviation (RSD) < 5.5% and RSD < 6.3%), stability (RSD < 19.3%), matrix effect (-8.3%-11.5%) and recovery (65.9%-116.2%). This method is convenient, sensitive and efficient, saving expensive materials and complicated derivatization procedures. The practical applicability of developed approach was also tested in urine samples to identify potential biomarkers of PAHs exposure in humans, and a great compromise was obtained between recoveries and extract convenience. The developed approach may be widely utilized for specific determination of OH-PAHs with isomer structure in urine samples. It is expected that the application of this method may provide powerful references for PAHs exposure assessment.

Pharmacokinetics and pharmacodynamics of cyclopropylfentanyl in male rats

BackgroundIllicitly manufactured fentanyl and its analogs are a major driving force behind the ongoing opioid crisis. Cyclopropylfentanyl is a fentanyl analog associated with many overdose deaths, but limited knowledge is available about its pharmacology. In the present study, we developed a bioanalytical method for the determination of cyclopropylfentanyl and its main metabolite cyclopropylnorfentanyl and evaluated pharmacokinetic-pharmacodynamic relationships in rats.MethodAn ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated for determination of cyclopropylfentanyl and cyclopropylnorfentanyl in rat plasma. Male Sprague–Dawley rats fitted with jugular catheters and temperature transponders received cyclopropylfentanyl (30, 100, and 300 μg/kg) or saline subcutaneously. Blood specimens were withdrawn over an 8-h time period, along with measurements of pharmacodynamic endpoints.ResultsThe analytical method was validated, and both analytes exhibited a low limit of quantification (15 pg/mL). Cyclopropylfentanyl caused dose-related increases in hot plate latency (ED50 = 48 µg/kg) and catalepsy (ED50 = 87 µg/kg) and produced long-lasting hypothermia at the highest dose. Plasma cyclopropylfentanyl rose rapidly in a dose-related fashion, reaching maximal concentration (Cmax) after 15–28 min, whereas metabolite Cmax occurred later at 45–90 min. Cyclopropylfentanyl Cmax values were similar to concentrations measured in non-fatal intoxications in humans; however, differences in parent drug: metabolite ratio indicated possible interspecies variance in metabolism.ConclusionOur study shows that cyclopropylfentanyl produces typical opioid-like effects in male rats. Cyclopropylfentanyl displays much greater analgesic potency when compared to morphine, suggesting that cyclopropylfentanyl poses increased overdose risk for unsuspecting users.

High performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method for detection and quantification of select NLRP3 inhibitors from brain tissue

The NLRP3 inflammasome is an essential component of the innate immune system and has been implicated in neurodegenerative and inflammatory disorders. Therefore, there is increasing interest to develop inhibitors of the NLRP3 inflammasome to achieve disease intervention. Recently, we have developed a series of sulfonamide-based NLRP3 inhibitors as potential treatments for neurodegenerative diseases. One of the challenges for CNS therapeutics is blood-brain barrier penetration. Therefore, a method to detect and compare the blood-brain barrier penetration of these inhibitors is required but has not yet been established. In this study, we established a method to evaluate and quantify the blood-brain barrier penetration of JC-171, one of our lead NLRP3 inhibitors in comparison with MCC950, another known urea-based NLRP3 inhibitor using high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method. The results suggest that this methodology has the ability to provide reliable measurements for brain exposure.

Exploring the Bile Stress Response of Lactobacillus mucosae LM1 through Exoproteome Analysis.

Lactobacillus sp. have long been studied for their great potential in probiotic applications. Recently, proteomics analysis has become a useful tool for studies on potential lactobacilli probiotics. Specifically, proteomics has helped determine and describe the physiological changes that lactic acid bacteria undergo in specific conditions, especially in the host gut. In particular, the extracellular proteome, or exoproteome, of lactobacilli contains proteins specific to host– or environment–microbe interactions. Using gel-free, label-free ultra-high performance liquid chromatography tandem mass spectrometry, we explored the exoproteome of the probiotic candidate Lactobacillus mucosae LM1 subjected to bile treatment, to determine the proteins it may use against bile stress in the gut. Bile stress increased the size of the LM1 exoproteome, secreting ribosomal proteins (50S ribosomal protein L27 and L16) and metabolic proteins (lactate dehydrogenase, phosphoglycerate kinase, glyceraldehyde-3-phosphate dehydrogenase and pyruvate dehydrogenases, among others) that might have moonlighting functions in the LM1 bile stress response. Interestingly, membrane-associated proteins (transporters, peptidase, ligase and cell division protein ftsH) were among the key proteins whose secretion were induced by the LM1 bile stress response. These specific proteins from LM1 exoproteome will be useful in observing the proposed bile response mechanisms via in vitro experiments. Our data also reveal the possible beneficial effects of LM1 to the host gut.

Which illicit drugs are injected in Oslo? A study based on analysis of drug residues in used injection equipment and self-reported information.

People who inject drugs (PWID) have a high risk of premature death due to fatal overdoses. Newly emerged fentanyls, much more potent than heroin and other opioids, may increase this risk further. Therefore, precise information on injected drugs is critical to improving prevention strategies. This study aimed to analyse drug residues in used injection equipment in order to determine drug and drug combinations and compare and complement findings with self-reported information. Used syringes and needles (n=766) were collected at the supervised drug consumption facilities, the needle exchange service and two low-threshold health services for problem drug users in Oslo, Norway. The material was collected every third month from June 2019 to June 2020 and analysed for 64 substances using highly specific analytical methods (ultra-high performance liquid chromatography tandem mass spectrometry). Additionally, a street-recruited sample of PWID was interviewed from 2017 to 2019 regarding their drug injection habits (n=572). Heroin (65.5%) or amphetamines (59.8%), often in combination (30.5%), were commonly detected in drug residues. Other opioids, stimulants or benzodiazepines were rarely detected (6.1%). Fentanyl was detected in only one syringe. Heroin was the most reported drug (77.6% during the past four weeks, 48.3% daily/almost daily), followed by amphetamines (57.5% during the past four weeks, 23.1% daily or almost daily). Injection of methadone, buprenorphine and dissolved tablets was self-reported more frequently than determined in drug residue findings. Analysis of the injection equipment proved useful as a non-invasive, rapid and accurate means to obtain detailed information on injected drugs in Oslo and supplement traditional PWID survey information.

Investigation and dynamic profiling of oligopeptides, free amino acids and derivatives during Pu-erh tea fermentation by ultra-high performance liquid chromatography tandem mass spectrometry

Microbial fermentation is the critical step of Pu-erh tea manufacture, which will induce dramatic changes in the chemical composition and content of tea. In this research, we applied multi-methods based on UHPLC-Q-TOF/MS to profile the dynamic changes of oligopeptides, free amino acids, and derivatives (OPADs) during Pu-erh fermentation and predicted the potential bioactivities in silico. A total of 60 oligopeptides, 18 free amino acids, and 42 amino acid derivatives were identified, and the contents of most of them decreased after fermentation. But several N-acetyl amino acids increased 7–36 times after fermentation, and they might be the potential inhibitors of neurokinin-1 receptor. Moreover, the results of metamicrobiology showed Aspergillus niger and Aspergillus luchuensis were more prominent to metabolize protein, oligopeptides, and amino acids. Overall, these findings provide valuable insights about dynamic variations of OPADs during Pu-erh tea fermentation and are beneficial for guiding practical fermentation and quality control of Pu-erh tea.

A Sensitive Ultra-High Performance Liquid Chromatography-Tandem Mass Spectrometry Method Based on Derivatization with 1-Nitro-2-Naphthaldehyde for Determination of Alkylhydrazines in Surface Water.

Alkylhydrazines are widely used in industrial fields. An analysis of alkylhydrazines in surface water is needed because these chemicals are likely to be discharged into wastewater and enter aquatic environments. An ultra-high performance liquid chromatography (UHPLC)-tandem mass spectrometry (MS/MS) method was developed to determine the levels of five alkylhydrazines (N, N-dimethylhydrazine, ethylhydrazine, 1-isopropylhydrazine, phenylhydrazine, and 1-methyl-1-phenylhydrazine) in surface water. This method is based on the derivatization of alkylhydrazines with 1-nitro-2-naphthaldehyde (NNA) in water. A derivatization reagent dosage of 0.5 mg NNA, a pH of 2, and a reaction time of 30 min at 40°C were determined to be the optimal conditions for UHPLC-MS/MS detection. The derivatives were injected into the LC system without additional extraction or purification steps. The proposed method was used under optimized conditions to detect alkylhydrazines in surface water, with the limit of quantification found to be 0.01-0.03 μg/L. The accuracy ranged from 91.0 to 106.0%, and the precision, expressed as the relative standard deviation, was less than 10%. Of the five alkylhydrazines, only N, N-dimethyl hydrazine was detected in the real samples at a concentration range of 0.010-0.041 μg/L. The developed method can be used to confirm the presence of alkylhydrazine residues in surface water and represents an important tool for evaluating the fate of alkylhydrazines in surface water. A UHPLC-MSMS method was developed in order to dtermine the alkylhydrazine in surface water after derivatization without an extraction or cleanup step.

Analysis of microplastics-sorbed endocrine-disrupting compounds in pellets and microplastic fragments from beaches

Microplastics present in marine ecosystems have become a major environmental issue. This problem is due to not only the harmful effects of microplastics on exposed organisms, but also to their ability to adsorb organic compounds, which can have a combined harmful effect. Steroid hormones are an important group of endocrine-disrupting compounds that display moderately lipophilic behavior and can, subsequently, be adsorbed on microplastics. For this reason, it is necessary to determine this type of contaminants adsorbed on microplastic waste.In order to investigate this issue, this work presents an analytical method based on ultrasound-assisted extraction and ultrahigh performance liquid chromatography tandem mass spectrometry (UAE-UHPLC-MS/MS) to determine the presence of 13 steroid hormones adsorbed on pellets and microplastic fragments. The different variables affecting the extraction process, such as solvent volume and extraction time, were optimized. The method showed excellent recoveries (above 80% for most compounds), satisfactory repeatability values and limits of detection (LoD) between 0.07 and 27.5 ng·g−1. Once optimized, the developed method was applied to the microplastic fragment samples and pellets collected from eight different beaches on the Canary Islands (Spain). In most samples, at least one hormone was detected and up to seven different steroid hormones in some samples. The steroid hormone concentrations in the studied samples ranged from < LoQ to 157 ng·g−1.

A multi-scalar investigation of the colouring materials used in textile wrappings of Egyptian votive animal mummies

Commonly exhibited in museum galleries, animal mummies have been the focus of interest of both visitors and researchers alike. The study of these animal remains not only provides new insights into embalming techniques, but also brings a unique perspective on religious, social and economic practices. Twenty animal mummies are discussed in this study, including cats, ibises, crocodiles, calves and birds of prey from the collections of the British Museum (London, UK) and the Museo Egizio (Turin, Italy). The external textile wrappings encasing the mummified body of the animals were investigated with the main aim of identifying the colourants used. In fact, these are mostly patterned using undyed and coloured (mostly red, brown and black) linen strips. Broadband multispectral imaging (MSI) was initially carried out to obtain preliminary information at the macro-scale on the distribution and chemical nature of the colouring agents. Fibre optic reflectance spectroscopy (FORS) was then used to survey several coloured areas of the textile wrappings. Safflower (Carthamus tinctorius) and red ochre were identified non-invasively. Representative samples were then taken and observed using optical microscopy (OM) and scanning electron microscopy (SEM), in order to obtain information at the micro-scale on the distribution of the colouring agents on the fibres, as well as the presence of other materials, including those from environmental contamination. Energy dispersive X-ray spectrometry (EDX) revealed the elemental composition of particles and clear areas of the fibres, whereas high performance liquid chromatography tandem mass spectrometry (HPLC–MS/MS) provided the identification of the organic dyes at a molecular level. The use of hydrolysable and condensed tannins, in combination with iron as a mordant, was found to be used in the very dark shades, which generally corresponded to the textiles with the worst state of preservation. Nevertheless, other aspects, such as fibre processing and bleaching, fungal attack and presence of coating materials appeared to play a role in the evaluation of the conservation state of these textiles. The characterisation of the dyes and the additional inorganic materials contributed to elucidating the production technology of the colours used for animal mummification, and provided insights into ancient dyeing methods.

An HPLC-MS/MS Method Using a Multitoxin Clean up Column for Analysis of Seven Mycotoxins in Aquafeeds.

In Guangdong Province of China, the climate is very wet, so there are many different fungi living in aquatic feeds, which produce mycotoxins. These compounds contaminate agricultural products worldwide and present a great threat to human health. It is necessary to determine their contamination level in aquatic feeds. A high performance liquid chromatography (HPLC) tandem mass spectrometry (MS/MS) method was developed for the quantitative analysis of aflatoxin B1, aflatoxin M1, T-2 toxin, HT-2 toxin, deoxynivalenol, ochratoxin, and zearalenone in fish and shrimp feed. Samples were extracted with acetonitrile-water (3+1, v/v), and degreased with acetonitrile-saturated hexane. The extract was cleaned up with a multitoxin column. The target compounds were separated on a C18 chromatographic column and analyzed simultaneously by electrospray ionization mass spectrometry in both positive and negative ion mode. Detected compounds were quantified using the matrix-matched external standard method. Under the optimized conditions, good linearities for the analytes in the corresponding concentration range were obtained, with correlation coefficients (r2) higher than 0.9948. LODs ranged from 1.83 to 12.63 μg/kg, and LOQs ranged from 5.49 to 37.89 μg/kg. Average recoveries for the target mycotoxins at three spiked levels ranged from 80.5 to 116.5% with RSD ranging from 2.4 to 10.4%. Twenty-three real aquafeed samples were determined by this method, and seven kinds of toxins were detected. The results show that the developed method can be successfully applied for the simultaneous determination of mycotoxins in aquatic feeds. Multitoxin purification columns proved to be a powerful technique for determining seven mycotoxins simultaneously. This method ensured simple sample pretreatment and less operation time. The established method was successfully applied to the analysis of seven mycotoxins species in aquatic feeds.

Ultra-high performance liquid chromatography tandem mass spectrometry analysis of UV filters in marine mussels (Mytilus galloprovinciallis) from the southern coast of Spain

Ultraviolet (UV) filters are a family of organic compounds widely used in sunscreens and personal care products (PCPs) as well as other materials such as plastics, toys and outdoor furniture, for their effectiveness in absorbing UVA and UVB radiation. These compounds directly enter the marine environment because of inefficient wastewater treatments and anthropogenic activities, posing a risk to the marine biota. The present study develops and validates a method to determine some of the most used UV filters (BP-1, BP-2, BP-3, BP-6, BP-8, 4-OH-BP and 4-MBC), in wild Mytilus galloprovincialis mussels using ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). The sample treatment is based on an ultrasound-assisted extraction followed by a clean-up step using C18 as sorbent. The methodology was satisfactorily validated, obtaining good features, and it was applied for the evaluation of the occurrence of the target analytes in mussels collected in five areas along the tourist coast of Granada (Spain) just after summer holydays period. The results showed a higher bioaccumulation in specimens sampled in recreational areas and with a closed geomorphology, being BP-3 the most predominant in all locations. BP-1 and BP-3 were quantified in all samples and the rest of UV filters were detected in most of them, except for BP-2. The data raises concern about the undesirable effects that UV filter pollution can cause in the area and highlights the need to establish practices that help preserve and sustain the marine ecosystem.

Simultaneous determination and pharmacokinetics studies of five isoflavones in rat plasma by UHPLC-MS/MS after oral administration of Radix Astragali extract

Abstract A rapid, sensitive and convenient method based on ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) was developed and validated for the simultaneous quantification of calycosin-7-O-β-d-glucoside (CCSG), ononin, calycosin, (6aR,11aR)-9,10-dimethoxypterocarpan-3-O-β-d-glucopyanoside (DPPG), and 7,2′-dihydroxy-3′,4′-dimethoxyisoflavan-7-O-β-d-glucopyanoside (DIFG) in rat plasma after oral administration of the methanol extraction from Radix Astragali. Theophylline played the role of internal standard (IS). Preparation of plasma samples by liquid-liquid extraction method with ethyl acetate after precipitation of protein with methanol. The analytes were detected with a triple quadrupole tandem mass spectrometery (MS) in multiple reaction monitoring (MRM) mode and a positive ion electrospray ionization (ESI). The method was validated with the concentration ranges of 1.96–62.69 ng/mL for CCSG, 1.70–54.5 ng/mL for ononin, 1.85–59.06 ng/mL for calycosin, 2.14–137.24 ng/mL for DPPG and1.96–125.25 ng/mL for DIFG, respectively. The method had the lower limit of quantification (LLOQ) with 0.49, 0.21, 0.92, 1.07, and 0.98 ng/mL for CCSG, ononin, calycosin, DPPG and DIFG respectively, and the precision less than 10%. The RSD of the accuracy was in the range of −4.35–8.91%. The results may be helpful to provide more accurate references to clinical application of this herb.

Cocktail Method: Effect of the Bletilla striata Extracts on CytochromeP450 Activity in Rat

Bletilla striata is a dried tuber of B striata (Thunb.) Reichb.f. of Orchidaceae plant, which is mainly used for hemoptysis, vomiting blood, trauma bleeding, sore swollen poison, and cracked skin. There have been few research reports on the effect of this herb on cytochrome P450 (CYP), therefore, the study was aimed to investigate the effects of the B striata extracts on the activity of 6 subtypes (CYP2D6, 1A2, 2C19, 2E1, 3A4, and 2C9) using a cocktail method. The B striata extracts were administrated to rats in 0.21 or 0.63 g/kg once a day for 7 or 14 days. The 3 control groups were used to ensure the accuracy of the results. Subsequently, a cocktail of tolbutamide, chlorzoxazone, midazolam, metoprolol, omeprazole, and caffeine was injected. A ultra performance liquid chromatography–tandem mass spectrometer was developed and validated to investigate the concentration of the probes and the pharmacokinetic parameters were calculated to investigate the effects of the extracts on the activity of 6 enzymes under different doses and different dosing periods. The results suggested that the B striata extracts could induce the activities of CYP2D6, 1A2, and 2C19 and could inhibit the activities of CYP2E1, 3A4, and 2C9. When used in combination with drugs that are metabolized by CYP2D6, 1A2, 2C19, 2E1, 3A4, and 2C9, appropriate dose adjustments were needed to avoid toxic side effects caused by drug interactions.