Development and validation of liquid chromatography-tandem mass spectrometry method to quantify dasatinib in plasma and its application to a pharmacokinetic study

Abstract Dasatinib, a potent oral multi-targeted kinase inhibitor against Src and Bcr-Abl, can decrease inflammatory response in sepsis. A simple and cost-effective method for determination of an effective dose dasatinib was established. This method was validated in human plasma, with the aim of reducing the number of animals used, thus, avoiding ethical problems. Dasatinib and internal standard lopinavir were extracted from 180 uL of plasma using liquid-liquid extraction with methyl tert-butil ether, followed by liquid chromatography coupled to triple quadrupole mass spectrometry in multiple reaction monitoring mode. For the pharmacokinetic study, 1 mg/kg of dasatinib was administered to mice with and without sepsis. The method was linear over the concentration range of 1-98 ng/mL for DAS in mice and human plasma, with r2>0.99 and presented intra- and interday precision within the range of 2.3 - 6.2 and 4.3 - 7.0%, respectively. Further intra- and interday accuracy was within the range of 88.2 - 105.8 and 90.6 - 101.7%, respectively. The mice with sepsis showed AUC0-t = 2076.06 h*ng/mL and Cmax =102.73 ng/mL and mice without sepsis presented AUC0-t = 2128.46 h*ng/mL. Cmax = 164.5 ng/mL. The described analytical method was successfully employed in pharmacokinetic study of DAS in mice.

Metabolic study of trimetazidine using ultra-high performance liquid chromatography-tandem mass spectrometry

Abstract In the present study, the application of ultra-high performance liquid chromatography-tandem mass spectrometry allowed us to study of known-as well as hitherto unknown-trimetazidine (TMZ) metabolites in human urine and to propose their renal excretion profiles. Urine samples from a healthy volunteer were analyzed at baseline and at 0-4 h, 4-8 h, 8-12 h, and 12-24 h after a single dose of TMZ. A dilute-and-shoot procedure was used as sample treatment before separation. Full-scan spectra of possible metabolites were acquired. Additionally, product ion scan spectra of precursor ions of interest were also acquired at two collision energies. Intact TMZ was a major excretion product, with a maximum concentration at 4-8 h after administration. Moreover, five minor metabolites were observed, namely trimetazidine-N-oxide (M1), N-formyl trimetazidine (M2), desmethyl-trimetazidine O-sulfate (M3), desmethyl-trimetazidine O-glucuronide (M4), and desmethyl-trimetazidine-N-oxide-O-glucuronide (M5). Metabolite M5 has not previously been reported. Excretion curves were constructed based on the chromatographic peak areas of specific mass transitions (precursor ion > product ion) related to each of the detected metabolites

Comprehensive chemical profiling and quantitative analysis of ethnicYi medicine Miao-Fu-Zhi-Tong granules using UHPLC-MS/MS / 中国天然药物

Developing analytical methods for the chemical components of natural medicines remains a challenge due to its diversity and complexity. Miao-Fu-Zhi-Tong (MFZT) granules, an ethnic Yi herbal prescription, comprises 10 herbs and has been clinically applied for gouty arthritis (GA) therapy. Herein, a series of chemical profiling strategies including in-house library matching, molecular networking and MS/MS fragmentation behavior validation based on ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) were developed for qualitative analysis of MFZT granules. A total of 207 compounds were identified or characterized in which several rare guanidines were discovered and profiled into alkyl substituted or cyclic subtypes. Moreover, network pharmacology analysis indicated that MFZT's anti-gout mechanism was mostly associated with the nuclear factor kappa-B (NF-κB) signaling, nucleotide oligomerization domain (NOD)-like signaling and rheumatoid arthritis pathways, along with the synergistic effect of 84 potential active compounds. In addition, a quantitative analytical method was developed to simultaneously determine the 29 potential effective components. Among them, berberine, pellodendrine, 3-feruloylquinic acid, neoastilbin, isoacteoside and chlorogenic acid derivatives at higher concentrations were considered as the chemical markers for quality control. These findings provide a holistic chemical basis for MFZT granules and will support the development of effective analytical methods for the herbal formulas of natural medicines.

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.

Rapid determination of acetaminophen in plasma by LC-MS/MS / 中华劳动卫生职业病杂志

Objective: To establish a method for the rapid determination of acetaminophen (APAP) in human plasma by LC-MS/MS. Methods: The plasma samples were extracted by methanol and acetonitrile (1: 1) and purified directly. C(18) column was used for sample separation. The mobile phase were methanol (5 mmol/L ammonium acetate) and water (5 mmol/L ammonium acetate). Samples were analyzed by LC MS/MS with the electrospray ionization multi reaction monitoring (MRM) mode. Results: The calibration curves of APAP was linear in the concentration range of 0~10 mg/L, the correlation coefficient (r) was greater than 0.999 0. The relative standard deviation within and between batches was less than 10%. The recovery rate were 96.81%~101.7%. The detection limit of the method was 0.1 μg/L and the lower limit of quantification was 0.3 μg/L. Conclusion: This method has strong specificity, high sensitivity and reliable determination results. It is suitable for the rapid analysis of clinical plasma samples.

Contamination status and exposure risk of mycotoxins in Coicis Semen / 中国中药杂志

By investigating the contamination status and predicting the exposure risk of mycotoxin in Coicis Semen, we aim to provide guidance for the safety supervision of Chinese medicinal materials and the formulation(revision) of mycotoxin limit standards. The content of 14 mycotoxins in the 100 Coicis Semen samples collected from five major markets of Chinese medicinal materials in China was determined by UPLC-MS/MS. The probability evaluation model based on Monte Carlo simulation method was established after Chi-square test and One-way ANOVA of the sample contamination data. Health risk assessment was performed on the basis of margin of exposure(MOE) and margin of safety(MOS). The results showed that zearalenone(ZEN), aflatoxin B_1(AFB_1), deoxynivalenol(DON), sterigmatocystin(ST), and aflatoxin B_2(AFB_2) in the Coicis Semen samples had the detection rates of 84%, 75%, 36%, 19%, and 18%, and the mean contamination levels of 117.42, 4.78, 61.16, 6.61, and 2.13 μg·kg~(-1), respectively. According to the limit standards in the Chinese Pharmacopoeia(2020 edition), AFB_1, AFs and ZEN exceeded the standards to certain extents, with the over-standard rates of 12.0%, 9.0%, and 6.0%, respectively. The exposure risks of Coicis Semen to AFB_1, AFB2, ST, DON, and ZEN were low, while 86% of the samples were contaminated with two or more toxins, which needs more attention. It is suggested that the research on the combined toxicity of different mycotoxins should be strengthened to accelerate the cumulative exposure assessment of mixed contaminations and the formulation(revision) of toxin limit standards.

Rapid identification of components in Wuzhuyu Decoction using UHPLC Q-Exactive Orbitrap MS~n and molecular network technology / 中国中药杂志

Wuzhuyu Decoction, the classical formula recorded in the Treatise on Febrile Diseases(Shang Han Lun), has been included in the Catalogue of Ancient Classic Prescriptions(the First Batch). Consisting of Euodiae Fructus, Ginseng Radix et Rhizoma, Zingiberis Rhizoma Recens, and Jujubae Fructus, it is effective in warming the middle, tonifying deficiency, dispelling cold, and descending adverse Qi, and is widely applied clinically with remarkable efficacies. For a classical formula, the chemical composition is the material basis and an important premise for quantity value transfer. This study aimed to establish a rapid identification method of chemical components in Wuzhuyu Decoction by high-resolution mass spectrometry(HR-MS) and molecular network. AQUITY UPLC BEH C_(18) column(2.1 mm×100 mm, 1.7 μm) was used for sample separation, and acetonitrile-0.1% formic acid in water was used as mobile phases for gradient elution. Q-Exactive Orbitrap MS data were collected in positive and negative ion modes, and GNPS molecular network was plotted according to the similarity of MS/MS fragmentation modes. Cytoscape 3.6.1 was used to screen molecular clusters with similar structures. Finally, the chemical components of Wuzhuyu Decoction were rapidly identified according to the controls, as well as the information of retention time, accurate relative molecular weight of HR-MS, and MS/MS multistage fragments. A total of 105 chemical components were identified in Wuzhuyu Decoction. This study can provide data for the follow-up quality control, standard substance research, and pharmacodynamic material research on Wuzhuyu Decoction, as well as references for the rapid qualitative analysis of the chemical components of Chinese medicine.

Determination of 10 mycotoxins in Hippophae Fructus medicinal and edible products by ultra-performance liquid chromatography- tandem mass spectrometry / 中国中药杂志

An analytical method for 10 mycotoxins in Hippophae Fructus medicinal and edible products was established in this study, and the contamination of their mycotoxins was analyzed. First of all, the mixed reference solution of ten mycotoxins such as aflatoxin, ochratoxin, zearalenone, and dexoynivalenol was selected as the control, and the Hippophae Fructus medicinal and edible products were prepared. Secondly, based on the ultra-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) technology, 10 mycotoxins in Hippophae Fructus medicinal and edible products were quantitatively investigated and their content was determined. Finally, the contamination of mycotoxins was analyzed and evaluated. The optimal analysis conditions were determined, and the methodological inspection results showed that the 10 mycotoxins established a good linear relationship(r>0.99). The method had good repeatability, test sample specificity, stability, and instrument precision. The average recovery rates of 10 mycotoxins in Hippophae Fructus medicinal products, edible solids, and edible liquids were 90.31%-109.4%, 87.86%-107.8%, and 85.61%-109.1%, respectively. Relative standard deviation(RSD) values were 0.22%-10%, 0.75%-13%, and 0.84%-8.5%, repsectively. Based on UPLC-MS/MS technology, the simultaneous determination method for the limits of 10 mycotoxins established in this study has fast detection speed, less matrix interference, high sensitivity, and accurate results, which is suitable for the limit examination of 10 mycoto-xins in Hippophae Fructus medicinal and edible products.

Deciphering chemical and metabolite profiling of Chang-Kang-Fang by UPLC-Q-TOF-MS/MS and its potential active components identification / 中国天然药物

Chang-Kang-Fang (CKF) formula, a Traditional Chinese Medicine (TCM) prescription, has been widely used for the treatment of irritable bowel syndrome (IBS). However, its potential material basis and underlying mechanism remain elusive. Therefore, this study employed an integrated approach that combined ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q/TOF-MS) with network pharmacology to systematically characterize the phytochemical components and metabolites of CKF, as well as elucidating its underlying mechanism. Through this comprehensive analysis, a total of 150 components were identified or tentatively characterized within the CKF formula. Notably, six N-acetyldopamine oligomers from CicadaePeriostracum and eight resin glycosides from Cuscutae Semen were characterized in this formula for the first time. Meanwhile, 149 xenobiotics (58 prototypes and 91 metabolites) were detected in plasma, urine, feces, brain, and intestinal contents, and the in vivo metabolic pathways of resin glycosides were elaborated for the first time. Furthermore, network pharmacology and molecular docking analyses revealed that alkaloids, flavonoids, chromones, monoterpenes, N-acetyldopamine dimers, p-hydroxycinnamic acid, and Cus-3/isomer might be responsible for the beneficial effects of CKF in treating IBS, and CASP8, MARK14, PIK3C, PIK3R1, TLR4, and TNF may be its potential targets. These discoveries offer a comprehensive understanding of the potential material basis and clarify the underlying mechanism of the CKF formula in treating IBS, facilitating the broader application of CKF in the field of medicine.

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.

Content determination of seven active components of Eucommiae Cortex in aortic vascular endothelial cells of spontaneously hypertensive rats by UPLC-MS/MS / 中国中药杂志

In the present study, the contents of seven active components [genipinic acid(GA), protocatechuic acid(PCA), neochlorogenic acid(NCA), chlorogenic acid(CA), cryptochlorogenic acid(CCA),(+)-pinoresinol di-O-β-D-glucopyranosid(PDG), and(+)-pinoresinol 4'-O-β-D-glucopyranoside(PG)] of Eucommiae Cortex in aortic vascular endothelial cells of spontaneously hypertensive rats(SHR) were simultaneously determined by ultra-high liquid chromatography-triple quadrupole mass spectrometry(UPLC-MS/MS). The qualified SHR models were selected. The primary aortic endothelial cells(VECs) of rats were separated and cultured by ligation and adherence, followed by subculture. After successful identification, an UPLC-MS/MS method for simultaneously determining the contents of GA, PCA, NCA, CA, CCA, PDG, PG in seven components of Eucommiae Cortex in VECs was established, including specificity, linearity, matrix effect, recovery, accuracy, precision and stability. The established method had the lo-west limit of quantification of 0.97-4.95 μg·L~(-1), accuracy of 87.26%-109.6%, extraction recovery of 89.23%-105.3%, matrix effect of 85.86%-106.2%, and stability of 86.00%-112.5%. Therefore, the established accurate UPLC-MS/MS method could rapidly and simultaneously determine the contents of the seven active components of Eucommiae Cortex in VECs of SHRs, which provided a refe-rence for the study of cellular pharmacokinetics of active components of Eucommiae Cortex extract.

Qualitative and quantitative study of constituents in Lysionoti Herba based on UHPLC-Q-Exactive Orbitrap HRMS and HPLC-UV / 中国中药杂志

Ultra-high performance liquid chromatography-quadrupole-Exactive Orbitrap high resolution mass spectrometry(UHPLC-Q-Exactive Orbitrap HRMS) was employed to systematically analyze the chemical constituents in Lysionoti Herba, and high perfor-mance liquid chromatography-ultraviolet(HPLC-UV) to determine the content of main compounds. A Synergi~(TM) Hydro-RP 100 Å colu-mn(2 mm×100 mm, 2.5 μm) was used for gradient elution with acetonitrile-0.1% aqueous formic acid as the mobile phase at a flow rate of 0.2 mL·min~(-1) and a column temperature of 40 ℃. MS and MS/MS were conducted with electrospray ionization(ESI) in both positive and negative modes. The chemical components in Lysionoti Herba were identified by comparison with the retention time and mass spectra of reference compounds and the relevant mass spectral data reported in MS databases and relevant literature. Furthermore, the content of five constituents(neochlorogenic acid, chlorogenic acid, forsythoside B, acteoside, and nevadensin) in different Lysiono-ti Herba samples was simultaneously determined by HPLC-UV at the wavelength of 330 nm. A total of 84 compounds were identified in Lysionoti Herba, including 27 flavonoids, 20 phenylethanoid glycosides, 5 amino acids, 18 organic acids, 1 alkaloid, 6 nucleosides, and 7 others. The content of neochlorogenic acid, chlorogenic acid, forsythoside B, acteoside, and nevadensin showed good linear relationship(r>0.999) with the peak area within certain concentration ranges, which were 3.22-102.90, 12.84-410.82, 31.63-1 012.01, 25.00-800.11, and 4.08-130.51 μg·mL~(-1), respectively. The instrument precision, method repeatability, and solution stability all met requirement, and the average recovery rate was 97.31%-100.2%, with RSD ranging from 0.95% to 2.4%. The content of the five components varied among different Lysionoti Herba samples collected from different regions of Guizhou, and the average content of forsythoside B was the highest. The established qualitative method can rapidly and efficiently identify the chemical components of Lysionoti Herba, and the developed HPLC-UV method can simultaneously determine the content of five components in a simple, ra-pid, and accurate manner, providing a scientific basis for the quality evaluation of Lysionoti Herba.

Qualitative and quantitative study of flavonoids in Notoginseng Radix et Rhizoma based on UPLC-Q-TOF-MS and HPLC-DAD / 中国中药杂志

The flavonoids in Panax notoginseng were qualitatively analyzed by ultra-high performance liquid chromatography-quadrupole-time of flight mass spectrometry(UPLC-Q-TOF-MS), and the content of three main flavonoids in P. notoginseng of different specifications and grades collected from different habitats was determined by HPLC-DAD. Flavonoids and anthocyanins were analyzed by UPLC-Q-TOF-MS/MS in the positive and negative ion modes, respectively. Twelve flavonoid glycosides and one anthocyanin glycoside in P. notoginseng were identified, but no flavonoid aglycones were detected. Among them, 12 compounds were identified in the underground part of P. notoginseng for the first time and eight compounds were first reported in this plant. Moreover, six and four compounds were identified in the Panax genus and the Araliaceae family for the first time, respectively. A method for simultaneous determination of three flavonoids in P. notoginseng was established by HPLC-DAD. The content of flavonoids in 721 P. notoginseng samples of 124 specifications and grades collected from 20 different habitats was simultaneously determined. Among three flavonoids determined, the content of quercetin-3-O-(2″-β-D-xylosyl)-β-D-galactoside was the highest with the average content in the tested samples of 161.0 μg·g~(-1). The content of compounds quercetin-3-O-hexosyl-hexoside and kaempferol-3-O-pentosyl-hexoside was relatively low, with the average content of 18.5 μg·g~(-1)(calculated as quercetin-3-O-sophoroside) and 49.4 μg·g~(-1)(calculated as kaempferol-3-O-sangbu diglycoside). There were significant differences in flavonoids content of samples from different production area. The content of flavonoids in spring P. notoginseng was significantly lower than that in winter P. notoginseng when the other influencing factors such as production areas, germplasm resources, and cultivation conditions were fixed. As for P. notoginseng of different specifications, the flavonoid content in the part connecting the taproot and the aboveground stem was significantly higher than that in other parts. The results of large-scale data showed that the flavonoid content gradually increased with the increase in the number of heads. There were significant differences between the flavonoid content in most specifications and grades, especially the 20-head P. notoginseng and countless head P. notoginseng, whose content was significantly lower and significantly higher than that of other specifications and grades, respectively. This study provides a scientific basis for the study of the effective components and quality control of P. notoginseng from the perspective of flavonoids.

Pharmacokinetics and tissue distribution of four alkaloids in Ermiao Pills and Sanmiao Pills in normal and arthritic model rats / 中国中药杂志

This work aimed to investigate the differences of pharmacokinetics and tissue distribution of four alkaloids in Ermiao Pills and Sanmiao Pills in normal and arthritic model rats. The rat model of arthritis was established by injecting Freund's complete adjuvant, and ultra-high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) in the positive ion multiple reaction monitoring(MRM) mode was used for the determination of four alkaloids in plasma and tissues of normal and arthritic rats after administration of Ermiao Pills and Sanmiao Pills, respectively. The differences in pharmacokinetics and tissue distribution of the four active components were compared, and the effect of Achyranthis Bidentatae Radix on the major components of Sanmiao Pills was explored. This study established an UPLC-MS/MS for simultaneous determination of four alkaloids, and the specificity, linearity, accuracy, precision, and stability of this method all met the requirements. Pharmacokinetics study found that as compared with normal rats, the AUC and C_(max) of phellodendrine, magnoflorine, berberine and palmatine in model rats were significantly decreased after administration of Ermiao Pills, the clearance rate CL/F was significantly increased, and the distribution and tissue/plasma concentration ratio of the four alkaloids in the liver, kidney, and joint were significantly reduced. Achyranthis Bidentatae Radix increased the AUC of phellodendrine, berberine, and palmatine, reduced the clearance rate, and significantly increased the distribution of the four alkaloids in the liver, kidney, and joints in arthritic rats. However, it had no significant effect on the pharmacokinetics and tissue distribution of the four alkaloids in normal rats. These results suggest that Achyranthis Bidentatae Radix may play a guiding role in meridian through increasing the tissue distribution of effective components in Sanmiao Pills under arthritis states.

Chromatographic profile of xanthones and flavonoids in the anti-dengue extracts of Fridericia samydoides (Cham. ) L. G. Lohmann (Bignoniaceae)

Abstract The flavonoids and xanthones present in the ethanol extracts of leaves and stems of Fridericia samydoides showed that anti-dengue activities in vitro were investigated qualitatively by liquid chromatography-ultraviolet-mass spectrometry in series. Nineteen flavones and fifteen xanthones were detected and characterized on the basis of their fragmentation pattern in the positive and negative ion mode tandem mass spectrometry spectra and ultraviolet bands. Acacetin, chrysin, vitexin, isovitexin, orientin, isoorientin, mangiferin, 2'-O-trans-caffeoylmangiferin, 2'-O-trans-coumaroylmangiferin and 2'-O-trans-cinnamoylmangiferin were identified by comparison with authentic samples. The other compounds detected were tentatively assigned by analysis of the spectral data and by comparison with literature reports. In addition, it performed the fractionation of the leaves extract leading to the isolation of mangiferin, isovitexin and isoorientin. All extracts and isolated compounds inhibited the Dengue virus replication cycle with EC50 less than 25.0 µg/mL for extracts and 272.5, 85.6 and 79.3 µg/mL for mangiferin, isovitexin and isoorientin, respectively.

Forensic Analysis of 9 Poisoning Death Cases Caused by Oral Administration of Diphenidol / 法医学杂志

OBJECTIVES@#To analyze the characteristics of diphenidol poisoning cases and to provide clues and technical means for the identification of such cases.@*METHODS@#Biological samples of 9 deaths caused by diphenidol poisoning were detected by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), and the characteristics of these cases were analyzed retrospectively.@*RESULTS@#Most of the deaths caused by diphenidol poisoning were young females. The dosage was between 60 and 300 tablets, and the mass concentration of diphenidol in the postmortem blood ranged from 0.87 to 99.00 μg/mL. There was no correlation between the dosage and the concentration of diphenidol in the blood.@*CONCLUSIONS@#Diphenidol poisoning has the characteristics of high concealment and lethality. More attention should be paid to suicide cases, and diphenidol should be recommended as a routine detection item to avoid missing detection.

Detection of Phosphatidylethanol in Whole Blood by UPLC-MS/MS / 法医学杂志

OBJECTIVES@#To establish the ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method to detect ethanol metabolites phosphatidylethanol (PEth) in whole blood.@*METHODS@#An appropriate amount of aqueous solution including 1% formic acid was added to 100 μL whole blood, the protein was precipitated with acetone, centrifuged and the supernatant was purified and enriched by using Bond Elut Certify column. The eluent was redissolved with 1/1 isopropanol/acetonitrile (v/v) solution after nitrogen blowing and then tested by UPLC-MS/MS. Selective reaction monitoring scanning was carried out in negative ionization mode, and quantitative analysis was performed by external standard method.@*RESULTS@#PEth showed a linear relationship over the concentration range of 1-160 ng/mL in whole blood (r=0.999 9) with peak area. The detection limit was 0.2 ng/mL, the quantification limit was 1 ng/mL, the recovery rate was 97.43%-103.61%, the accuracy was 0.99%-1.77%, the intra-day precision was 0.4%-2.4%, and the inter-day precision was 1.1%-3.3%, and the matrix effect was 91.00%-99.55%. PEth was not detected in the in vitro blood samples supplemented with ethanol. PEth was detected positive in three drunk driving cases, and the concentration were 195.49, 83.67 and 876.12 ng/mL, respectively.@*CONCLUSIONS@#The established method has high sensitivity and specificity and the analysis results are accurate. It is suitable for the qualitative and quantitative analysis of PEth in whole blood.

Detection of Exogenous γ-Hydroxybutyric Acid in Rat Blood Exosomes / 法医学杂志

OBJECTIVES@#To find a method to distinguish exogenous gamma-hydroxybutyrate (GHB) from endogenous GHB by establishing ultra-high performance liquid chromatography-mass spectrometry (UPLC-MS) based on exosome for quantitative detection of GHB in the rat blood.@*METHODS@#Adult male SD rats were divided into 1 h, 5 h, 10 h administration group and control group. After 1 h, 5 h and 10 h of single precursor of GHB gamma-butyrolactone (GBL) intraperitoneal injection in administration groups, 5 mL blood was collected from the abdominal aorta. Meanwhile, the control group was given a same dose of normal saline, and 5 mL blood was collected at 1 h. Among the 5 mL blood, 0.5 mL was directly detected by HPLC-MS after pretreatment, and exosomes were extracted from the remaining blood by differential centrifugation and detected.@*RESULTS@#The concentration of GHB in the control group was (87.36±33.48) ng/mL, and the concentration with administration at 1 h, 5 h and 10 h was (110 400.00±1 766.35) ng/mL, (1 479.00±687.01) ng/mL and (133.60±12.17) ng/mL, respectively. The results of exosome detection showed that no peak GHB signal was detected in the control group and the 10 h administration group, and the concentrations of GHB at 1 h and 5 h administration groups were (91.47±33.44) ng/mL and (49.43±7.05) ng/mL, respectively.@*CONCLUSIONS@#GHB was detected in blood exosome by UPLC-MS, which indicated that exogenous GHB could be detected in plasma exosomes, while endogenous GHB could not be detected, suggesting that this method may be used as a basis to determine whether there is exogenous drug intake.

Identification of Q-markers for Cistanches Herba based on HPLC-Q-TOF-MS/MS and network pharmacology / 中国中药杂志

This study aims to establish a method for analyzing the chemical constituents in Cistanches Herba by high performance liquid chromatography(HPLC) and quadrupole-time-of-flight tandem mass spectrometry(HPLC-Q-TOF-MS/MS), and to reveal the pharmacological mechanism based on network pharmacology for mining the quality markers(Q-markers) of Cistanches Herba. The chemical constituents of Cistanche deserticola and C. tubulosa were analyzed via HPLC-Q-TOF-MS/MS. The potential targets and pathways of Cistanches Herba were predicted via SwissTargetPrediction and DAVID. The compound-target-pathway-pharmacological action-efficacy network was constructed via Cytoscape. A total of 47 chemical constituents were identified, involving 95 targets and 56 signaling pathways. We preliminarily elucidated the pharmacological mechanisms of echinacoside, acteoside, isoacteoside, cistanoside F, 2'-acetylacteoside, cistanoside A, campneoside Ⅱ, salidroside, tubuloside B, 6-deoxycatalpol, 8-epi-loganic acid, ajugol, bartsioside, geniposidic acid, and pinoresinol 4-O-β-D-glucopyranoside, and predicted them to be the Q-markers of Cistanches Herba. This study identified the chemical constituents of Cistanches Herba, explained the pharmacological mechanism of the traditional efficacy of Cistanches Herba based on network pharmacology, and introduced the core concept of Q-markers to improve the quality evaluation of Cistanches Herba.

Study on critical quality attributes of Qingjin Huatan Decoction based on serum pharmacochemistry / 中国中药杂志

Qingjin Huatan Decoction is a classic prescription with the effects of clearing heat, moistening lung, resolving phlegm, and relieving cough. In order to explore the critical quality attributes of Qingjin Huatan Decoction, we identified the blood components of Qingjin Huatan Decoction by ultra-performance liquid chromatography quadrupole time of flight mass spectrometry(UPLC-Q-TOF-MS) under the following conditions, chromatographic column: Acquity UPLC BEH C_(18) column(2.1 mm×100 mm, 1.7 μm); mobile phase: 0.1% formic acid acetonitrile(A)-0.1% formic acid in water(B); gradient elution; flow rate: 0.2 mL·min~(-1); column temperature: 30 ℃; injection volume: 5 μL. The electrospray ionization(ESI) source was used to collect data in both positive and negative ion modes under the following conditions, capillary voltage: 3 kV for the positive ion mode and 2 kV for the negative ion mode; ion source temperature: 110 ℃; cone voltage: 30 V; cone gas flow rate: 50 L·h~(-1); nitrogen degassing temperature: 350 ℃; degassing volume flow rate: 800 L·h~(-1); scanning range: m/z 50-2 000. In this experiment, a total of 66 related components of Qingjin Huatan Decoction were identified, including 22 prototype components and 44 metabolites. The results of this study preliminarily revealed the pharmacodynamic material basis of Qingjin Huatan Decoction in vivo, which has provided an experimental basis for the determination of quality markers of Qingjin Huatan Decoction and the development of new drugs.