Evaluation of A Liver Yin Deficiency Mouse Model Based on Untargeted Metabolomics / 中国实验方剂学杂志

ObjectiveBased on ultra performance liquid chromatography-quadrupole-time-of-flight tandem mass spectrometry（UPLC-Q-TOF-MS）， to evaluate the establishment of a mouse model of liver Yin deficiency by thyroid tablet suspension combined with 10% carbon tetrachloride（CCl4） from the perspective of non-targeted metabolomics， in order to lay the foundation for the establishment of a traditional Chinese medicine（TCM） syndrome model. MethodA total of 24 mice were randomly divided into blank group and model group. The model group was given thyroid tablet suspension（0.003 2 g·kg-1） by gavage for 14 consecutive days， and 10% CCl4（5 mL·kg-1） was intraperitoneally injected once a week to establish a liver Yin deficiency model， while the blank group was injected with an equal amount of olive oil intraperitoneally and gavaged with an equal amount of distilled water， and was fed with normal feed. After the modeling was completed， 6 mice in each group were randomly selected， the levels of alanine aminotransferase（ALT）， aspartate aminotransferase（AST）， cyclic adenosine monophosphate（cAMP）， cyclic guanosine monophosphate（cGMP）， interleukin（IL）-6， IL-10， tumor necrosis factor-α（TNF-α）were measured in the mice serum， and malondialdehyde（MDA）， superoxide dismutase（SOD）， total protein（TP）， hydroxyproline（HYP） and other indicators were measured in the mice liver. Liver tissue sections were taken for hematoxylin-eosin（HE） staining and observing pathological changes. The remaining 6 mice in each group were subjected to UPLC-Q-TOF-MS combined with principal component analysis（PCA） and orthogonal partial least squares-discriminant analysis（OPLS-DA） were used to screen differential metabolites in the liver Yin deficiency mouse model， Kyoto Encyclopedia of Genes and Genomes（KEGG） database was used to analyze the corresponding metabolic pathways of differential metabolites. ResultCompared with the blank group， mice in the model group showed liver Yin deficiency manifestations such as reduced body weight， fatigue and sleepiness， disheveled and lusterless hair， irritability. The levels of ALT， cAMP/cGMP， IL-6， AST， MDA， cAMP， TNF-α significantly increased（P<0.05， P<0.01）， while the levels of SOD， IL-10 and cGMP significantly decreased（P<0.05， P<0.01）， and the changes of HYP and TP were not statistically significant. Hepatic steatosis and distortion of the radial arrangement of the liver plate cells were seen in the section images of the model group， endogenous substances were clearly separated， and 252 differential metabolites were identified in the serum samples， which were mainly involved in the metabolic pathways of purine metabolism， steroid hormone biosynthesis and pyrimidine metabolism. A total of 229 differential metabolites were identified in the liver samples， mainly involving nucleotide metabolism， purine metabolism， steroid hormone biosynthesis， pyrimidine metabolism， antifolate resistance， insulin resistance， primary bile acid biosynthesis， prostate cancer， sulfur relay system， arachidonic acid metabolism and other metabolic pathways. ConclusionThe successful establishment of liver Yin deficiency model in mice by CCl4 combined with thyroid hormone is evaluated through the investigation of serum and liver metabolomics， combined with biochemical indicators， which provides a biological basis and experimental foundation for the Yin deficiency syndrome model of TCM.

Disease spectrum and genetic profiles of neonatal inborn errors of metabolism in selected areas of Nanning city / 中国新生儿科杂志

Objective:To study disease spectrum and genetic profiles of inborn errors of metabolism (IEM) among newborns in selected areas of Nanning city.Methods:From July 2019 to December 2021, neonates born and received IEM screening in our hospital were prospectively enrolled. Heel blood samples were tested using tandem mass spectrometry as IEM screening. Neonates with positive results were called back for recheck. Whole exome sequencing was used to detect possible pathogenic genes in suspected cases and IEM was diagnosed combining clinical manifestations. Sanger sequencing method was used for the diagnosed neonates and their parents to confirm the diagnoses.Results:A total of 16 207 live-birth neonates were enrolled. For initial IEM screening, 1 423 neonates were positive (8.8%) and 1 311 were called back (92.1%). 15 cases were suspected with IEM and 8 were diagnosed. The overall detection rate was 1∶2 026. Among 8 confirmed cases, 4 cases had amino acid metabolism disorders (2 cases of phenylketonuria, 1 case of Citrin deficiency and 1 case of tyrosinemia), 2 cases had organic acid metabolism disorders (1 case of methylmalonic acidemia and 1 case of glutaric acidemia) and 2 cases had fatty acid oxidation disorders (1 case of carnitine palmitotransferaseⅡdeficiency and 1 case of primary carnitine deficiency). 5 cases had homozygous genetic variants (2 in PAH, and 1 in SLC25A13, SLC22A5 and FAH, respectively) and 3 had heterozygous genetic variants (1 in CPT2, MUT, and GCDH, respectively). During follow-up, all 8 cases had normal growth and developmental outcomes after standardized treatment.Conclusions:The overall detection rate of IEM is high, with varied genetic profiles in selected areas of Nanning. Timely genetic testing may lead to early diagnosis and treatment and improve the quality of life of neonates.

Pharmacokinetics effect of 8 components of Baizhu Shaoyao San with processing method based on UPLC-MS/MS / 国际中医中药杂志

Objective:To explore the pharmacokinetics effect of 8 components of processed Baizhu Shaoyao San on rats.Methods:The rats were divided into processing group and unprocessing group, administered with decoction of Baizhu Shaoyao San by gavage respectively. Then, blood was collected from fundus vein at certain time to obtain the plasma. Finally, the contents of 8 components in plasma were detected and compared by UPLC-MS/MS method, and the methodology of the experiment was tested. The drug concentration in blood and the collection time of blood were analyzed by DAS software, and the time curves of different groups were obtained, the pharmacokinetic parameters were calculated.Results:The blood peak concentration, peak time, area under the drug time curve, and average residence time of 8 components in the serum of rats in the raw product group and the fried product group were different to varying degrees.Conclusion:Processed Baizhu Shaoyao San could influence the behavior of the components measured in rats, which may affect the clinical therapeutic effect of Baizhu Shaoyao San.

Simultaneous determination of 18 common disinfection by-product residues in drinking water by high performance liquid chromatography-tandem mass spectrometry / 上海预防医学

ObjectiveA method was developed for the rapid determination of 18 common disinfection by-products including halogenated oxides and haloacetic acid （HAAs） in drinking water by high performance liquid chromatography tandem mass spectrometry （HPLC-MS/MS）. MethodThe water sample was filtered by 0.22 μm hydrophilic membrane then the analytes were separated on a PFP （2.1 mm× 100 mm， 2.7 μm） pentafluorophenyl column with 0.1% acetic acid and acetonitrile as mobile phase gradient elution. Ionization in anionic electrospray mode was detected by multi-reaction monitoring （MRM） mode. The external standard method was used for quantitation. ResultsThe correlation coefficients of 18 disinfection by-products were above 0.999 in the corresponding linear range. The average spiked recoveries of 1， 10 and20 times of LOQ of each analyte were 91.6%‒101.8%， and the relative standard deviation （RSD） was 1.2%‒6.4%. The LOD and LOQ were 0.020‒2 μg·L-1 and 0.050‒5 μg·L-1， respectively. ConclusionThis method is simple， sensitive and accurate， and could be used for the routine analysis of 18 common disinfection by-products in drinking water.

Simultaneous determination of 15 bile acids in Tongren niuhuang qingxin pills by UPLC-MS/MS / 中国药房

OBJECTIVE To establish a method for simultaneous determination of 15 bile acids in Tongren niuhuang qingxin pills， and to determine the contents of 15 batches of samples. METHODS Using dehydrocholic acid as internal standard， the determination was performed by ultra-high performance liquid chromatography-tandem mass spectrometry （UPLC-MS/MS） method. The determination was performed on Hypersil GOLD C18 column with methanol-0.1% formic acid solution as the mobile phase by gradient elution at the flow rate of 0.2 mL/min. The column temperature was 40 ℃ ， and the sample size was 2 µL. Using heated electrospray ion source， parallel reaction monitoring mode scanning was performed in negative ion mode. SPSS 24.0 software was used for chemical pattern recognition analysis of content determination results. RESULTS The 15 bile acid components had a good linear relationship with peak area （all R2≥0.998 9）； their precision， repeatability and stability were all good （all RSD≤5.49%）； the average recoveries were 93.8%-105.7% （RSD was 0.5%-5.8%）. The average contents of taurocholic acid， 7-oxodeoxycholic acid， 12-dehydrocholic acid， glycocholic acid， 3-oxo-7α， 12α-hydroxy-5β-cholanoic acid， taurochenodeoxycholic acid， 3α-hydroxy- 7-oxo-5β -cholanic acid， hyocholic acid， taurodeoxycholic acid sodium salt hydrate， hyodeoxycholic acid， cholic acid， glycochenodeoxycholic acid， glycodeoxycholic acid， chenodeoxycholic acid and deoxycholic acid were 670.56， 25.97， 10.54， 280.12， 4.04， 29.81， 182.98， 813.55， 120.95， 220.31， 797.37， 18.37， 68.59， 30.13， 59.82 μg/g， respectively. Both cluster analysis and principal component analysis divided 15 batches of Tongren niuhuang qingxin pills into 2 categories， S1-S12 as one category and S13-S15 as the other category. CONCLUSIONS The established method is accurate， sensitive and specific， and can determine many types of bile acids. It also can quickly achieve the quantitative analysis of 15 bile acids in Tongren niuhuang qingxin pills， which is suitable for the quality control of this drug.

Determination of 22 phospholipids in serum by ultra performance liquid chromatography-tandem mass spectrometry / 中华劳动卫生职业病杂志

Objective: To establish ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the determination of 22 phospholipids in serum. Methods: In September 2022, Using synthetic non endogenous phospholipids as internal standard, phospholipids in serum were extracted by methanol-dichloromethane (2∶1, V/V) protein precipitation method. Chromatographic separation was achieved on an ACQUITY UPLC BEH shield RP18 column, and the mobile phase was methanol/water (5∶95, V/V) containing 10 mM ammonium formate and methanol. Detection was performed in multiple reaction monitoring mode with ion mode switching. And the method was applied by analyzing phospholipids in the serum of coal workers' pneumoconiosis patients. Results: The 22 phospholipids showed good linear relationships in their respective concentration ranges and the correlation coefficients were higher than 0.990. The spiked recoveries of the 22 phospholipids were 81.03%-121.63% at the three spiked levels. The intra-assay were less than 14.52%, and the inter-assay were less than 15.00%. Conclusion: The method with the advantages of simplicity, stability and high sensitivity, and it can be used for the analysis of phospholipids in serum.

Predictive Analysis of Quality Markers of Anticoagulant Activity of Kunning Granules Based on UHPLC-Q-TOF-MS/MS and Spectral Efficacy / 中国实验方剂学杂志

ObjectiveTo perform a predictive analysis of the quality marker（Q-Marker） for the anticoagulant activity of Kunning granules. MethodThe chemical components of Kunning granules were analyzed by ultra high performance liquid chromatography-quadrupole-time of flight tandem mass spectrometry（UHPLC-Q-TOF-MS/MS） on a Waters ACQUITY UPLC HSS T3 column（2.1 mm×100 mm， 1.8 μm） with the mobile phase of acetonitrile（A）-25 mmol∙L-1 ammonium acetate aqueous solution（B） for gradient elution （0-5 min， 5%-22%A； 5-10 min， 22%-30%A； 10-15 min， 30%-95%A； 15-20 min， 95%-5%A； 20-30 min， 5%A）， flow rate of 0.2 mL∙min-1， column temperature at 30 ℃， injection volume of 1 μL， electrospray ionization（ESI）， positive and negative ion detection modes. Interaction analysis between the targets of chemical components and the targets of abnormal uterine bleeding（AUB） was performed by network pharmacology， and the key components were screened through network topology analysis. The fingerprints of 10 batches of Kunning granules were established by high performance liquid chromatography（HPLC）， the anticoagulant activity of the granules was determined by blood coagulation method and fibrinogen plate method， and the spectrum-effective relationship was established. The components co-occurring in the topological analysis and spectrum-effective relationship were selected as Q-Markers， and their anticoagulant activities were verified and confirmed. ResultA total of 475 chemical components were identified from Kunning Granule， of which 22 key components such as salvianolic acid B， paeoniflorin， naringin and neohesperidin， were the potential material basis for the treatment of AUB. The spectrum-effective analysis showed that peaks 7（paeoniflorin）， 9（naringin）， 10（neohesperidin） and 11（salvianolic acid B） were the optimal principal components， and in vitro activity test showed that these four components could better characterize their anticoagulant activity. ConclusionSalvianolic acid B， paeoniflorin， neohesperidin and naringin may be Q-Markers for the anticoagulant activity of Kunning granules.

Rapid determination of four herbicides in urine with ultra-high performance liquid chromatography-triple quadrupole tandem mass spectrometry / 预防医学

Objective@#To establish a ultra-high performance liquid chromatography-tandem triple quadrupole mass spectrometry method for rapid simultaneous determination of quinclorac, acetochlor, butachlor and metolachlor in urine.@*Methods@#Urine samples were diluted 10 times, prepared into the mixed standard solution, and subjected to gradient elution on the ACQUITY UPLC BEH C18 column (100 mm×2.1 mm, 1.7 μm) with 0.1% formic acid and acetonitrile as the mobile phase. The quinclorac, acetochlor, metolachlor and butachlor levels were determined using electrospray ionization-positive ultra-high performance liquid chromatography-tandem triple quadrupole mass spectrometry with the multiple reaction monitoring mode.@*Results@#Four herbicides were effectively separated on the ACQUITY UPLC BEH C18 column (100 mm× 2.1 mm, 1.7 μm), and good linear relationships were observed for quinclorac, acetochlor and butachlor at 1 to 25 μg/L and for metolachlor at 0.2 to 25 μg/L, with all linear correlation coefficients of >0.999. The detection limts of quinclorac, acetochlor, butachlor and metolachlor were 0.10, 0.10, 0.20 and 0.01 μg/L, respectively. The recovery rates of quinclorac, acetochlor and butachlor were 107.42%, 93.94% and 90.27% from urine samples at a spiked level of 5 µg/L, with relative standard deviations of 4.82%, 3.84% and 6.76%, and the recovery rate of metolachlor was 89.51% at a spiked level of 0.5 µg/L, with a relative standard deviation of 8.98%.@*Conclusion@#The chromatography and mass spectrometry conditions are optimized in this ultra-high performance liquid chromatography-tandem mass spectrometry, which is effective for rapid simultaneous determination of quinclorac, acetochlor, metolachlor and butachlor in urine samples.

Analysis of Forty-Two Psychoactive Substances in a Single Hair by Micro-Segmental Technique / 法医学杂志

OBJECTIVES@#To establish an LC-MS/MS method based on single hair micro-segmental technique, and verify the detection of 42 psychoactive substances in 0.4 mm hair segments.@*METHODS@#Each piece of single hair was cut into 0.4 mm segments and extracted by sonication and the segments were immersed in dithiothreitol-containing extraction medium. Mobile phase A was the aqueous solution containing 20 mmol/L ammonium acetate, 0.1% formic acid, and 5% acetonitrile. Mobile phase B was acetonitrile. An electrospray ionization source in positive ion mode was used for data acquisition in multiple reaction monitoring (MRM) mode.@*RESULTS@#The 42 psychoactive substances in hair had a good linear relationship within their respective linear ranges (r>0.99), the limits of detection were 0.2-10 pg/mm, the limits of quantification were 0.5-20 pg/mm, the intra-day and inter-day precisions were 1.5%-12.7%, the intra-day and inter-day accuracies were 86.5%-109.2%, the recovery rates were 68.1%-98.2%, and the matrix effects were 71.3%-111.7%. The method was applied to hair samples collected from one volunteer at 28 d after a single dose of zolpidem, with zolpidem detected in 5 hairs was 1.08-1.60 cm near the root tip, and the concentration range was 0.62-20.5 pg/mm.@*CONCLUSIONS@#The micro-segmental technique of single hair analysis can be applied to the investigation of drug-facilitated sexual assault cases.

Blood metabolites in preterm infants with retinopathy of prematurity based on tandem mass spectrometry: a preliminary study / 中国当代儿科杂志

OBJECTIVES@#To study new biomarkers for the early diagnosis of retinopathy of prematurity (ROP) by analyzing the differences in blood metabolites based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) and metabolomics.@*METHODS@#Dried blood spots were collected from 21 infants with ROP (ROP group) and 21 infants without ROP (non-ROP group) who were hospitalized in the Sixth Affiliated Hospital of Sun Yat-sen University from January 2013 to December 2016. LC-MS/MS was used to measure the metabolites, and orthogonal partial least squares-discriminant analysis was used to search for differentially expressed metabolites and biomarkers.@*RESULTS@#There was a significant difference in blood metabolic profiles between the ROP and non-ROP groups. The pattern recognition analysis, Score-plot, and weight analysis obtained 10 amino acids with a relatively large difference. Further statistical analysis showed that the ROP group had significant increases in blood levels of glutamic acid, leucine, aspartic acid, ornithine, and glycine compared with the non-ROP group (P<0.05). The receiver operating characteristic curve analysis showed that glutamic acid and ornithine had the highest value in diagnosing ROP.@*CONCLUSIONS@#Blood metabolites in preterm infants with ROP are different from those without ROP. Glutamic acid and ornithine are the metabolic markers for diagnosing ROP. LC-MS/MS combined with metabolomics analysis has a potential application value in the early identification and diagnosis of ROP.

Formation and characteristics of polystyrene nanoplastic-plant protein corona / 生物工程学报

To investigate the formation of polystyrene nanoplastic-plant protein corona and its potential impact on plants, three differently modified polystyrene nanoplastics with an average particle size of 200 nm were taken to interact with the leaf proteins of Impatiens hawkeri for 2 h, 4 h, 8 h, 16 h, 24 h, and 36 h, respectively. The morphological changes were observed by scanning electron microscopy (SEM), the surface roughness was determined by atomic force microscopy (AFM), the hydrated particle size and zeta potential were determined by nanoparticle size and zeta potential analyzer, and the protein composition of the protein corona was identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The proteins were classified in terms of biological processes, cellular components, and molecular functions to study the adsorption selection of nanoplastics to proteins, investigate the formation and characteristics of polystyrene nanoplastic-plant protein corona and predict the potential impact of protein corona on plants. The results showed that the morphological changes of the nanoplastics became clearer as the reaction time extends, as evidenced by the increase in size and roughness and the enhancement of stability, thus demonstrating the formation of protein corona. In addition, the transformation rate from soft to hard protein corona was basically the same for the three polystyrene nanoplastics in the formation of protein corona with leaf proteins under the same protein concentration conditions. Moreover, in the reaction with leaf proteins, the selective adsorption of the three nanoplastics to proteins with different isoelectric points and molecular weights differed, and the particle size and stability of the final formed protein corona also differed. Since a large portion of the protein fraction in protein corona is involved in photosynthesis, it is hypothesized that the formation of the protein corona may affect photosynthesis in I. hawkeri.

Optimization of pretreatment methods for N-nitrosamine compounds in ready-to-eat aquatic products / 预防医学

Objective@#To optimize the pretreatment method of N-nitrosamine compounds in ready-to-eat aquatic products. @*Methods@#Market-sold ready-to-eat aquatic products were collected, homogenized and distilled by steam. The samples were extracted for 10 minutes using dispersive liquid-liquid microextraction (DLLME) with ethanol, trichloromethane and sodium chloride (3.0 g). After centrifugation, the organic phase in the lower layer was collected and subjected to gas chromatography-tandem mass spectrometry (GC-MS/MS). The six common N-nitrosamine compounds were determined in ready-to-eat aquatic products using multiple reaction monitoring mode (MRM) and quantified by the internal standard method. @*Results@#The optimized method exhibited a good linear relationship at concentrations of 10.0 to 500 μg/L for determination of 6 N-nitrosamine compounds (correlation coefficient of greater than 0.999), with 0.05 to 0.60 μg/kg limit of detection, 0.15 to 1.60 μg/kg limit of quantitation, mean spiked recovery rates of 71.8% to 108.9%, and relative standard deviations of 1.4% to 8.6%. N-Nitrosodimethylamine showed the highest detection rate in 20 market-sold ready-to-eat aquatic products (90%), and the detection rates of N-Nitrosopyrrolidine, N-Nitrosodiethylamine and N-dibutylnitrosamine were 15%, 10% and 10%, respectively. @*Conclusion@#Steam distillation combined with DLLME may optimize the pretreatment method of N-nitrosamine compounds in ready-to-eat aquatic products and meet the measurement requirements.

Rapid screening of 28 alkaloids in food poisoning samples by liquid chromatography-tandem mass spectrometry / 中国热带医学

@#Abstract: Objective　To investigate a poisoning incident caused by eating eight treasure congee, and establish liquid chromatography (LC)-mass spectrometry (MS)/MS screening method of 28 alkaloids to provide references for disposal of similar poisoning incidents. Methods　LC-MS/MS was used for screening 28 alkaloids in the urine, eight treasure congee and food raw material, and the detected alkaloids were quantified. Samples were extracted with 0.4% formic acid aqueous solution and separated by a Acquity UPLC BEH C18 column (1.7 μm, 100 × 2.1 mm). Acetonitrile-0.2% formic acid aqueous solution was used as the mobile phase and gradient elution was adopted. The ionization mode was electrospray positive ionization mode, and the detection method was multi-reaction monitoring (MRM). Analytes were quantified with the external standard method. Results　In the concentration range of 0-100 ng/mL, the linear correlation coefficient r were greater than 0.999 for 28 alkaloids. The recovery of 28 alkaloids in urine sample ranged from 63.0% to 105.0%, and the relative standard deviations (RSDs) were between 5.8% and 8.6%. The recovery of 28 alkaloids in eight treasure congee sample ranged from 72.0% to 109.0%, and the RSDs were between 6.3% and 9.7%. The recovery of 28 alkaloids in semen sesami nigrum sample ranged from 60.0% to 95.0%, and the RSDs were between 4.8% and 8.2%. Hyoscyamine (2 380.0 ng/mL), scopliamine (3.6 ng/mL) and rac-anisodamine (4.7 ng/mL) were detected in the patient's urine. Hyoscyamine (63.3 μg/g), scopliamine (5.7 μg/g) and rac-anisodamine (2.1 μg/g) were detected in eight treasure congee. Hyoscyamine (901.0 μg/g), scopliamine (80.0 μg/g) and rac-anisodamine (30.1 μg/g) were detected in the seed of Datura stramonium L. The ratio of scopliamine and hyoscyamine in the seed of D. stramonium was 1∶11, which complies with the characteristics of D. stramonium L. In urine sample, the proportion of scopliamine and rac-anisodamine was 0.15% and 0.20%, and hyoscyamine accounted for 99.65%. Conclusion　Seed morphology, the content range and proportion of three alkaloids are all in accord with the characteristics of D. stramonium. Combined with the clinical symptoms of atropine poisoning, it can be deduced that this incident is a family food poisoning caused by accidental consumption of seed of D. stramonium L. The method can provide technical support for the clinical diagnosis and treatment of alkaloid poisoning patients, and also provide a basis for emergency detection and disposal of alkaloid poisoning events.

The PK bioanalysis method study of c-Met antibody-drug conjugate (RC108) in cynomolgus monkey / 药学学报

Antibody-drug conjugate (ADC) has the characteristics of low toxicity and high efficiency, and plays an important role in cancer treatment. However, due to the complexity of its structure, it brings difficulties in pharmacokinetic (PK) bioanalysis. This study established an analytical method for the detection of ADC (RC108) in cynomolgus monkey plasma by ligand-binding assay (LBA) and liquid chromatography tandem mass spectrometry (LC-MS/MS), which was used to analyze and quantify the total antibody, bound antibody and free drug in cynomolgus monkey plasma. Based on the LBA method, rabbit anti-RC108 Fab and mouse anti-MMAE (monomethyl auristatin E) mAb were pre-coated in 96-well plates as the total antibody and antibody binding reagents, respectively. The samples to be tested were added, and then the detection reagents were added in turn. Goat anti-human IgG (H+L)-HRP, chromogenic solution tetramethylbenzidine (TMB), H2SO4 terminate the reaction, read data at 450 nm/630 nm wavelength of microplate reader; LC-MS/MS analysis method quantifies MMAE concentration, and refer to relevant regulations for methodological validation. The analytical method for quantifying total antibody, bound antibody and free drug of RC108 drug obtained good accuracy and precision, and the selectivity, dilution linearity, hook effect, parallelism and stability were verified. Meet the requirements of biological analysis. Finally, a bioanalytical method for the determination of the concentration of the test substance RC108 (total antibody, conjugated antibody, free MMAE) in cynomolgus monkey plasma with high sensitivity and high throughput was established by LBA and LC-MS/MS method. Subsequent non-clinical research on PK research in cynomolgus monkeys will provide technical support.

Simultaneously quantitative analysis of 35 components in gualoupi injection using hydrophilic interaction liquid chromatography tandem mass spectrometry / 药学学报

A hydrophilic interaction chromatography tandem mass spectrometry method was developed for simultaneous quantification of 35 components in gualoupi injection. The analytes were separated with an ACQUITY XBridge Amide column using 20 mmol·L-1 ammonium formate aqueous solution (pH 3.0) as mobile phase A and 20 mmol·L-1 ammonium formate (pH 3.0)∶acetonitrile (1∶9) as mobile phase B for gradient elution. Mass spectrometry with dynamic multiple reaction monitoring and external standard method were used for quantitative analysis. A total of 35 components were determined in 10 batches of gualoupi injection. The results showed that the 35 compounds had a good linear relationship within their respective concentration ranges with the correlation coefficients (R2 > 0.998 0), the recoveries ranged from 76.6% to 118.5%. The results showed that γ-aminobutyric acid, trigonelline, alanine, threonine, homoserine, citrulline, and leucine were abundant in gualoupi injection, while nicotinamide, methylsuccinic acid, cytosine and choline account for a low percentege. The present study provides an important reference for elucidation of the effective material basis and the improvement of quality standard of gualoupi injection.

Exploring Mechanism of Renshen Guben Oral Liquids in Treating Renal Fibrosis Based on Metabolomics and Network Pharmacology / 中国实验方剂学杂志

ObjectiveTo investigate the mechanism of Renshen Guben oral liquids（RGOL） in treatment of mice with renal fibrosis based on metabolomics and network pharmacology. MethodC57BL/6 mice were randomly divided into control group， model group and RGOL group， 12 mice in each group. Except for the control group， mice in the other groups were induced into unilateral ureteral obstruction（UUO） model by UUO. After preparation of the model， an aqueous solution of 4.2 g·kg-1 extract powder was administered by gavage to RGOL group for 14 d， and an equal amount of distilled water was administered by gavage to the control and model groups. After the last administration on the 14th day， urine was collected and detected by ultra-high performance liquid chromatography-triple quadrupole tandem mass spectrometry（UPLC-QQQ-MS/MS） with 0.1% formic acid aqueous solution as mobile phase A， and acetonitrile-isopropanol（70∶30） as mobile phase B for gradient elution（0-1 min， 5%B； 1-5 min， 5%-30%B； 5-9 min， 30%-50%B； 9-11 min， 50%-78%B； 11-13.5 min， 78%-95%B； 13.5-14 min， 95%-100%B； 14-16 min， 100%B； 16-16.1 min， 100%-5%B； 16.1-18 min， 5%B）， column temperature of 40 ℃， flow rate of 0.4 mL·min-1， electrospray ionization（ESI）， collection range of m/z 50-900. Through network pharmacology， the targets of components in RGOL and the targets of renal fibrosis were analyzed interactively， and the key components and key targets were screened by network topology analysis， and DAVID platform was used to predict the signaling pathways of RGOL for the treatment of renal fibrosis. ResultA total of 7 differential metabolites involving 8 metabolic pathways were identified in RGOL for the treatment of renal fibrosis. The network pharmacology revealed that 36 key components in RGOL were related to 7 differential metabolites， mainly ginsenosides， notoginsenosides and nucleotides. Based on the herbs-components-targets-pathways network， a total of 23 key targets related to the treatment of renal fibrosis by RGOL were highlighted， which together with the differential metabolites were involved in linoleic acid metabolism， arginine biosynthesis， tricarboxylic acid cycle（TCA）， arginine and proline metabolism and other pathways. ConclusionBased on metabolomics and network pharmacology， this study preliminarily identified 7 differential metabolites， 36 potential pharmacodynamic components and 23 key targets and 4 key pathways in RGOL for the treatment of renal fibrosis， providing an experimental basis for the clinical application and mechanism study of this preparation.

Establishment and application of detection methods of dicamba in drinking water / 环境与职业医学

Background Dicamba is widely used in agricultural production in China, but it is extremely soluble in water and can be harmful to human health when it enters the body via water drinking. It is necessary to establish an accurate, sensitive, and rapid detection method to determine the residues of dicamba in domestic drinking water. Objective To establish two methods for the determination of dicamba residues in drinking water by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and gas chromatography-tandem mass spectrometry (GC-MS/MS) respectively. Methods The conditions of the proposed method using HPLC-MS/MS included CAPCELL PAK ST chromatographic column, ammonium formate water solution and methanol as the mobile phase, and isocratic elution. The system was operated under multiple reaction monitoring mode and electrospray negative ionization mode. Trimethylsilylated diazomethane was used as a derivatizing agent for GC-MS/MS, and an external standard curve was used to evaluate the system. The residues of dicamba in seven water samples of tap water or secondary water supply from six regions in Chengdu were detected by the established systems to evaluate their applicability and to understand the status quo of dicamba residues in drinking water. Results For the HPLC-MS/MS, the linear range of dicamba was 1.00-100 μg·L−1, the regression equation was \begin{document}$\hat Y $\end{document}=1250.9X+2681.5, the correlation coefficient was 0.9988, the relative standard deviations were 1.23%-26.3%, the limit of detection was 0.95 μg·L−1, and the spiked recoveries were 91.8%-111%. For the GC-MS/MS, the linear range of dicamba was 0.200-10.0 μg·L−1, the regression equation was \begin{document}$\hat Y $\end{document}=190597X+40911, the correlation coefficient was 0.9993, the relative standard deviations were 0.64%-3.90%, the limit of detection was 0.18 μg·L−1, and the spiked recoveries were 97.3%-105%. No dicamba residue was identified in the seven water samples of tap water or secondary water supply from six regions in Chengdu by the proposed methods. Conclusion The two detection methods established in this study are sensitive and rapid, meet the requirements from the detection of dicamba residues in drinking water, and provide an experimental basis for subsequent research on the detection of dicamba residues. In the future, it is necessary to continue to pay attention to the pollution of dicamba in drinking water in Chengdu.

Determination of bongkrekic acid in corn flour by direct extraction ultra-high performance liquid chromatography tandem mass spectrometry / 公共卫生与预防医学

Objective To establish a direct extraction ultra-high performance liquid chromatography tandem mass spectrometry method for the determination of bongkrekic acid in corn flour. Methods Bongkrekic acid was directly extracted with 80% methanol from corn flour samples, and the supernatant after vortex and centrifugation was determined after passing through membrane filtration. At the same time, the corn flour samples were extracted by solid phase extraction. The determination results of the two methods were compared. Results The linearity of standard series was good within the range of2-20 μg/L, and the linearity coefficient was＞0.999. The determination result of the positive sample by direct extraction method was 193.40 mg/kg (n=6). Adding the standard to the blank sample at the levels of 2, 6, and 10 μg/L, the calculated recovery rate was 75.82% - 99.33%, and the relative standard deviation was 3.54 % - 8.45%. The detection limit of the method reached 6 μg/kg. After extraction by solid phase extraction, the determination result of the positive sample was 196.84 mg/kg (n=6). The recovery rate was 77.12% -100.83%, with a relative standard deviation of 8.32% - 9.54%. Conclusion Compared with the solid phase extraction, the direct extraction method for the extraction of bongkrekic acid from corn flour has the advantages of rapidity, simplicity, and cost savings.

Serum Metabonomics Study of Difference in Lymph Node Metastasis of Pancreatic Ductal Adenocarcinoma Based on LC-MS / 肿瘤防治研究

Objective To investigate the differential metabolites of lymph node metastasis in pancreatic ductal carcinoma (PDAC) and provide new ideas for the pathogenesis, early diagnosis and treatment of metastatic pancreatic cancer. Methods Forty serum specimens of patients with pancreatic ductal carcinoma were collected and divided into lymph node metastasis group (18 cases) and non-metastasis group (22 cases). Thirty-one serum specimens were also collected from the healthy control group. Liquid chromatographytandem mass spectrometry was used to analyze the differential metabolites and metabolic pathways between patients with PDAC and healthy controls as well as between lymph node metastasis and non-metastasis groups. Results Principal component analysis and partial least squares-discriminant analysis revealed statistically significant differences in metabolites and metabolic pathways between patients with PDAC and the healthy controls and between lymph node metastasis and non-metastasis groups. The differences in profiles were also statistically significant. Seventy-six different metabolites and 11 metabolic pathways were screened between patients with PDAC and the healthy controls, among which phenylalanine metabolism and histidine metabolism were the two most influential metabolic pathways. Four different metabolites were screened between lymph node metastasis and non-metastasis groups, and the expression of ethopropazine and phenylalanine were upregulated but the expression of tetrahydrodeoxycorticosterone and oxprenolol were downregulated. Conclusion Metabolites are significantly altered in the lymph node metastasis group of patients with PDAC compared with the non-metastasis group. Ethopropazine, phenylalanine, tetrahydrodeoxy corticosterone, and oxprenolol are potential biomarkers of lymph node metastasis in patients with PDAC.

Determination of pentachlorophenol in wooden chopping boards with gas chromatography-tandem mass spectrometry / 预防医学

Objective@#To optimize the determination of pentachlorophenol in wooden chopping boards through pretreatment of miniaturized samples.@*Methods@# The pretreated wooden chopping board samples were subjected to ultrasound extraction (1 mL of 0.5 mol/L K2CO3 added in 5 mL extraction solution) in 8 mL acetone and 2 mL water, followed by derivatization with 0.3 mL acetic anhydride, extraction with n-hexane and separation with DB-5ms column (30 m×0.25 mm, 0.25 μm). Gas chromatography tandem mass spectrometry (GC-MS/MS) was performed in multiple reaction monitoring (MRM) mode with quantitative analysis using the internal standard method.@*Results@#The GC-MS/MS assay showed a good linear relationship within the range of 0.01 to 0.2 µg/mL (R2>0.999), with a 0.003 mg/kg limit of detection and 0.01 mg/kg limit of quantitation. The mean recovery rates were 84.2% to 96.7% at spiked concentrations of 0.003, 0.01 and 0.03 mg/kg, with relative standard deviation of 2.2% to 6.1%.@*Conclusions@#The established GC-MS/MS assay is easy to perform, environment-friendly, highly accurate and sensitivity, which is feasible for determination of pentachlorophenol in wooden chopping boards.