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Traditional Chinese medicines (TCMs) are gaining more and more attentions all over the world. The focus of TCMs researches were gradually shifted from chemical research to the combination study of chemical and life sciences. However, obtaining precise information of TCMs process in vivo or in vitro is still a bottleneck in bioanalysis of TCMs for their chemical composition complexity. This paper reviewed the recent analytical methods especially mass spectrometry technology in the bioanalysis of TCMs, and data processing techniques in the qualitative and quantitative analyses of metabolite of TCMs. Additionally, the difficulties encountered in the analyzing biological samples in TCMs and the solutions to these problems have been mentioned. [ABSTRACT FROM AUTHOR]

Highlights: [•] It firstly developed an LC–MS method for simultaneous measurement of timosaponin B-II and timosaponin A-III. [•] The method is simple, sensitive and specific, with a short analysis time (8min). [•] There were obvious differences in the pharmacokinetics between timosaponin B-II and timosaponin A-III. [•] This study revealed the practical value of the compatibility of herb-pair remedy in clinic. [Copyright &y& Elsevier]

• Develop and validate an LC-MS/MS method for the quantification of six small molecule Anti-SARS-CoV-2 drugs in plasma. • The devised methodology was effectively utilized in a pharmacokinetic study following the oral administration of six small molecule Anti-SARS-CoV-2 drugs in rats. • Presents a significant tool for preclinical and clinical investigations of six small molecule Anti-SARS-CoV-2 drugs, generating interest in further research on anti-Covid19 drugs. Antiviral treatment for COVID-19 is considered an effective tool in reducing the rate of severe cases and deaths. As of June 2023, a total of six small molecule antiviral drugs have been conditionally approved for marketing by the National Medical Products Administration (NMPA) within China. In this study, a method of HPLC-MS/MS was established and validated for the determination of six small molecule antiviral drugs in plasma using Lamivudine as an internal standard. The chromatographic separation was performed using gradient elution with an ACE 3 C 18 -PFP column (3.0 mm × 150 mm, 3 μm), and the mobile phase consisted of deionized water and acetonitrile/water (90:10, v/v), both with 10 mmol/L of ammonium acetate and 0.1 % ammonium hydroxide added. Quantitative analysis of the six small molecule drugs was carried out through selective reaction monitoring based on the positive ion spray ionization mode. The method exhibited excellent precision, accuracy, recovery, and linearity, and it was used to determine the pharmacokinetic characteristics in rats. Our work not only established a bioanalytical method for six small molecule antiviral drugs but also provided scientific references for clinical pharmacokinetic studies. [ABSTRACT FROM AUTHOR]

Nephrolithiasis is a systemic metabolic disease with a worldwide incidence that is increasing yearly, as well as a high recurrence rate; however, this disease's pathogenesis has not been thoroughly elucidated to date. Several epidemiological studies have shown that the risk for developing kidney stones increases in people with dyslipidemia. To explore the mechanism of lipid-induced kidney stones, we established a mouse model for renal urolithiasis based on intraperitoneal injections of glyoxylate (120 mg/kg/d). Lipidomics based on ultra high performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry (UPLC-QTOF-MS/MS) was performed to determine the changes in lipid metabolism in serum and kidneys. We screened 179 and 196 different lipid metabolites in the kidneys and serum, respectively, including fatty acyls, glycerophospholipids, sphingolipids, glycerolipids and prenol lipids. We found that polyunsaturated fatty acids, such as arachidonic acid, eicosapentaenoic acid, and docosahexoenoic acid, and ceramides and lysophosphocholines mediated inflammatory responses and that the oxidative stress induced by oleylethanolamine and glycerophosphoethanolamine plasmalogens is closely related to the development of kidney stones. These results provide strong evidence for the relationship between lipid metabolism and the development of kidney stones and suggest a clear direction for future research. [ABSTRACT FROM AUTHOR]

• Development of a sensitive and reliable LC-MS/MS method for the accurate quantification of six α-hydroxyl ceramides in serum. • Strong support for the research of biological function of α-hydroxyl ceramides in the future. • Revealing the α-hydroxyl ceramides associated with sepsis. Alpha-hydroxy ceramides are not only the precursors of many complex sphingolipids, also play a major role in membrane homeostasis and cellular signal transduction. However, current research rarely involved quantitative methods for α-hydroxy ceramides, which greatly restricts the study of its biological function. This work aimed to develop a reliable assay for the accurate quantification of α-hydroxy ceramides in vivo study. LC-MS/MS method was developed for the accurate quantification of six α-hydroxy ceramides of Cer(d18:1/16:0(2OH)), Cer(d18:1/18:0(2OH)), Cer(d18:1/18:1(2OH)), Cer(d18:1/20:0(2OH)), Cer(d18:1/22:0(2OH)) and Cer(d18:1/24:1(2OH)) in mice serum. This assay was validated with low limit of quantitation of 3.125 ng/mL, a dynamic range of 3.125–400 ng/mL (R2 > 0.99), precision (<15 %), and accuracy (88 % to 115 %). Applying the method to the determination of α-hydroxy ceramides in the serum of sepsis mice, the levels of Cer(d18:1/16:0(2OH)), Cer(d18:1/20:0(2OH)), Cer(d18:1/24:1(2OH)) were significantly elevated in LPS-induced septic as compared to the normal control. In conclusion, this LC-MS method was qualified in α-hydroxy ceramides quantification in vivo and a significant association was found between α-hydroxy ceramides and sepsis. [ABSTRACT FROM AUTHOR]

It has been proved that the purine metabolic pathway has been implicated in various biological disorders including gout, diabetes, coronary heart diseases, and neurodegenerative diseases. The analysis of the purine metabolic pathway in organisms reveals important alterations under different physiological and pathological conditions, which contributes to the pathological study, diagnosis, and therapy of related diseases. In the present study, an ultra-high performance liquid chromatography with ultraviolet and tandem mass spectrometry (UHPLC-UV–MS/MS) method was developed for conducting the comprehensive analysis of the metabolite profiles of the purine pathway in rat plasma through a single analysis. The purine metabolites including adenosine-5′-monophosphate, guanosine-5′-monophosphate, adenosine, inosine, guanosine, inosine-5′-monophosphate, deoxyadenosine, deoxyguanosine, deoxyinosine, xanthine, hypoxanthine, and uric acid, were separated and quantified in the short running time of 10 min. After rapid chromatographic separation achieved by an Agilent Zorbax SB-Aq column, high concentration of uric acid and the remaining purine metabolites at lower levels were respectively detected by ultraviolet detector and triple quadruple mass spectrometry within a single analysis. The proposed method was validated by applying charcoal-stripped plasma as a matrix and it was proved to be linear ( R 2 > 0.982), accurate (with a relative error for accuracy < ± 15% and the relative standard deviation for intra- and inter-run precision <11%) and reproducible (with a matrix effect ranging between 86.49% and 111.44% with a maximum RSD of 8.69%). As a result, the method was successfully applied to the quantification of the endogenous purine metabolites in rat plasma. It was found that the concentration levels of the purine metabolites may keep a physiological balance as an integrated system in normal individuals and the concentration level of uric acid in rat plasma was 64 μM which was more than 200 times greater than the other purine metabolites. The established method and the measurement of the concentration of these purines in normal rat plasma may help the investigation of the action mechanisms between purine disorders and related diseases. [ABSTRACT FROM AUTHOR]

Phellodendrine, a quaternary ammonium alkaloid extracted from the dried bark of Phellodendrom chinensis Schneid and Phellodendrom amurense Rupr, has the effect of suppressing cellular immune response, reducing blood pressure and antinephritis. However, few investigations have been conducted for the pharmacokinetic study of phellodendrine. Thus, a rapid, simple and reliable ultra-high performance liquid chromatography–tandem quadrupole mass spectrometry (UHPLC–QQQ MS/MS) method has been established for quantification of phellodendrine in rat plasma and tissues by using magnoflorine as internal standard. The chromatographic separation was achieved on an Agilent ZORBAX SB-C18 column (4.6 mm × 50 mm, 1.8 μm) by gradient elution using 0.1% aqueous formic acid (A) and methanol (B). Triple quadrupole mass detection with multiple reaction monitoring mode was used to monitor the ion transitions, at m / z 342.20 → 192.20 for phellodendrine and m / z 342.20 → 58.20 for internal standard, respectively. The developed method was fully validated and successfully applied to the pharmacokinetics and tissue distribution study of phellodendrine after intravenous administration. The lower limits of quantification were 0.5 ng/mL for plasma samples, 2.5 ng/g for brain and 1 ng/g for other tested tissues. Precisions and accuracy values were within the Food and Drug Administration acceptance criteria, the recovery and matrix effects were between 87.8–113.5%. The area under the curve (AUC 0−t ) ranged from 15.58 to 57.41 mg/L min and Cmax were between 1.63–4.93 mg/L. The results showed that phellodendrine was eliminated in 120 min in plasma and most of tissues and the highest concentrations of phellodendrine were found in the kidney. This study may provide a basis for the further study of phellodendrine. [ABSTRACT FROM AUTHOR]

An ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC–MS/MS) approach was developed and validated for the determination of ginkgolide L (GL) in rat plasma and tissues using diazepam as internal standard (IS). Detection was performed on a triple quadrupole MS system using multiple reaction monitoring (MRM) mode in positive mode. Sample preparation was carried out through a liquid–liquid extraction with ethyl acetate. The chromatographic separation was achieved by using an Agilent ZORBAX SB-Aq column with a mobile phase of 0.5% aqueous formic acid (A) and methanol (B). The monitored transitions were set at m/z 391.14 → 271.10 for GL and m/z 285.08 → 193.10 for IS, respectively. The validated method was successfully applied to the pharmacokinetic and tissue distribution study of GL in rats after intravenous administration. Good linearity was found between 2.5–2000 ng/mL ( r > 0.996) for plasma samples, and calibration curves were also linear for other tissue samples over a wide range. The results indicated that GL has linear pharmacokinetic properties after intravenous administration at three doses. GL could distribute to tissues quickly and the major distribution tissue of GL in rats was liver. This was the first report of pharmacokinetic and tissue distribution data for GL. [ABSTRACT FROM AUTHOR]

Ginkgolide K (GK), a derivative compound of ginkgolide B, has been recently isolated from the leaves of Ginkgo biloba . It is a powerful natural platelet activate factor (PAF) antagonist, and also has obvious protect effects for cerebral ischemia. However, no reports have been described for the pharmacokinetic study of GK. In this study, a simple, sensitive and reliable ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method has been developed for the determination of GK in rat plasma and tissues. Biological samples were pretreated by an efficient liquid–liquid extraction with ethyl acetate. The chromatographic separation was achieved on an Agilent ZORBAX SB-Aq column (4.6 mm × 50 mm, 1.8 μm) with a mobile phase of 0.5% aqueous formic acid (A)–menthol (B). Quantitation was carried out on a triple quadruple mass spectrometry using positive electrospray ionization in multiple reaction monitoring mode. Diazepam was used as internal standard (IS). The ion transitions monitored were set at m/z 407.10 → 389.20 and m/z 285.08 → 193.10 for GK and IS, respectively. The developed method was fully validated and successfully applied to the pharmacokinetics and tissue distribution study of GK after intravenous administration. The current results have indicated that pharmacokinetic parameters of GK vary in a dose-dependent manner with rapid elimination in 4 h. The major distribution tissues of GK in rats were liver and kidney. This study would provide critical information to promote the future study of GK. [ABSTRACT FROM AUTHOR]