Development of UPLC-MS/MS method for studying the pharmacokinetic interactions of fuzuloparib with curcumin in rats.

Fuzuloparib is a novel orally bioactive poly-ADP-ribose polymerase inhibitor (PARPi), which was approved by the Chinese Regulatory Agency (CRA) in 2020 for the treatment of platinum-sensitive recurrent ovarian, fallopian tube, and primary peritoneal cancers. This study firstly presents a rapid and accurate ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for analyzing the levels of fuzuloparib and its major metabolite (SHR165202), and to investigate drug-drug interaction between fuzuloparib and curcumin in vitro and in vivo studies. After protein precipitation with acetonitrile, mobile phase consisted of acetonitrile and 0.1 % formic acid with a gradient elution was used to successfully separate fuzuloparib, SHR165202 and talazoparib (internal standard, IS). The results indicated that fuzuloparib and SHR165202 had good linearity over the calibration range of 2-50 ng/mL and 1-20 ng/mL, respectively. The precision, accuracy, stability, matrix effect, and extraction recovery required for methodological validation all complied with the requirements of the Bioanalytical Method Validation Guidelines. In vitro microsome incubation experiments, curcumin exhibited inhibitory effect on fuzuloparib in both rat liver microsomes (RLM) and human liver microsomes (HLM) with half-maximal inhibitory concentration (IC50) value of 10.54 µM and 47.64 µM, respectively, and the corresponding mechanism was non-competitive. Furthermore, the inhibitory mechanism of curcumin on fuzuloparib was validated through molecular docking. In pharmacokinetic experiments in rats, curcumin significantly altered the plasma exposure of fuzuloparib, resulting in significant increases in AUC(0-t) and Cmax of fuzuloparib and a significant decrease in CLz/F. Moreover, the metabolite SHR165202 showed significant increases in AUC(0-t), AUC(0-∞), Tmax and Cmax and a significant decrease in CLz/F. This further supports the notion that curcumin could inhibit the metabolism of fuzuloparib. Therefore, when co-administering fuzuloparib and curcumin in clinic, it is recommended to monitor plasma levels of fuzuloparib and pay close attention to adverse effects. If necessary, the dose of fuzuloparib needs to be reduced.

Characterising the urinary acylcarnitine and amino acid profiles of HIV/TB co-infection, using LC-MS metabolomics.

INTRODUCTION: The human immunodeficiency virus (HIV) and tuberculosis (TB) co-infection presents significant challenges due to the complex interplay between these diseases, leading to exacerbated metabolic disturbances. Understanding these metabolic profiles is crucial for improving diagnostic and therapeutic approaches. OBJECTIVE: This study aimed to characterise the urinary acylcarnitine and amino acid profiles, including 5-hydroxyindoleacetic acid (5-HIAA), in patients co-infected with HIV and TB using targeted liquid chromatography mass spectrometry (LC-MS) metabolomics. METHODS: Urine samples, categorised into HIV, TB, HIV/TB co-infected, and healthy controls, were analysed using HPLC-MS/MS. Statistical analyses included one-way ANOVA and a Kruskal-Wallis test to determine significant differences in the acylcarnitine and amino acid profiles between groups. RESULTS: The study revealed significant metabolic alterations, especially in TB and co-infected groups. Elevated levels of medium-chain acylcarnitines indicated increased fatty acid oxidation, commonly associated with cachexia in TB. Altered amino acid profiles suggested disruptions in protein and glucose metabolism, indicating a shift towards diabetes-like metabolic states. Notably, TB was identified as a primary driver of these changes, affecting protein turnover, and impacting energy metabolism in co-infected patients. CONCLUSION: The metabolic profiling of HIV/TB co-infection highlights the profound impact of TB on metabolic pathways, which may exacerbate the clinical complexities of co-infection. Understanding these metabolic disruptions can guide the development of targeted treatments and improve management strategies, ultimately enhancing the clinical outcomes for these patients. Further research is required to validate these findings and explore their implications in larger, diverse populations.

Development and validation of QuEChERS-based LC-MS/MS method for simultaneous quantification of eleven N-nitrosamines in processed fish meat, processed meat, and salted fish products.

N-Nitrosamines (NAs) pose a threat to food safety due to their carcinogenic and mutagenic properties. In this study, we developed and validated a QuEChERS-based LC-MS/MS method for the simultaneous analysis of 11 NAs in 74 processed fish meat, processed meat, and salted fish products. Sample preparation was optimized by screening two versions of QuEChERS buffer, four extraction methods, and eight purification methods. The optimal analytical approach was validated for three product categories in terms of linearity, matrix effects, accuracy, and precision. Satisfactory precision and accuracy were demonstrated, with relative recoveries of 70-120% for the 11 NAs. The limits of detection for fish meat, processed meat, and salted fish products were 0.12-7.50, 0.12-4.14, and 0.10-7.81 ng·g-1, respectively. Among the 11 NAs, nine were detected in all 74 samples. This methodology could be applied to monitor NA levels to ensure the safety and quality of food products.

Numbers of Exchangeable Hydrogens from LC-MS Data of Heavy Water Metabolically Labeled Samples.

Labeling with deuterium oxide (D2O) has emerged as one of the preferred approaches for measuring the synthesis of individual proteins in vivo. In these experiments, the synthesis rates of proteins are determined by modeling mass shifts in peptides during the labeling period. This modeling depends on a theoretical maximum enrichment determined by the number of labeling sites (NEH) of each amino acid in the peptide sequence. Currently, NEH is determined from one set of published values. However, it has been demonstrated that NEH can differ between species and potentially tissues. The goal of this work was to determine the number of NEH for each amino acid within a given experiment to capture the conditions unique to that experiment. We used four methods to compute the NEH values. To test these approaches, we used two publicly available data sets. In a de novo approach, we compute NEH values and the label enrichment from the abundances of three mass isotopomers. The other three methods use the complete isotope profiles and body water enrichment in deuterium as an input parameter. They determine the NEH values by (1) minimizing the residual sum of squares, (2) from the mole percent excess of labeling, and (3) the time course profile of the depletion of the relative isotope abundance of monoisotope. In the test samples, the method using residual sum of squares performed the best. The methods are implemented in a tool for determining the NEH for each amino acid within a given experiment to use in the determination of protein synthesis rates using D2O.

Sensitive quantification of mevalonate pathway intermediates and prediction of relative novel analogs by chemical derivatization-based LC-MS/MS.

The mevalonate (MVA) pathway plays a crucial role in the occurrence and progression of various diseases, such as osteoporosis, breast cancer, and lung cancer, etc. However, determining all the MVA pathway intermediates is still challenging due to their high polarity, low concentration, chelation effect with metal compartments, and poor mass spectrometric response. In this study, we established a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method coupled with N2, N2, N4, N4-tetramethyl-6-(4-(piperazin-1-ylsulfonyl) phenyl)-1,3,5-triazine-2,4-diamine (Tmt-PP) labeling for the simultaneous analysis of all MVA intermediates in biospecimens. Chemical derivatization significantly improved the chromatographic retention, peak shape, and detection sensitivity of the analytes. Moreover, we employed a method named mass spectrum calculation to achieve the absolute quantification of the isomers, i.e., isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP). The established method was fully qualified and applied to explore the difference of these metabolites in cisplatin-resistant non-small cell lung cancer (NSCLC) cells. Additionally, several MVA intermediate analogs, including isopentenyl monophosphate or dimethylallyl monophosphate (IMP/DMAMP), geranyl monophosphate (GMP), 5-triphosphomevalonate (MTP), and isopentenyl triphosphate or dimethylallyl triphosphate (ITP/DMATP), were identified for the first time using a knowledge-driven prediction strategy. We further explored the tissue distribution of these novel metabolites. Overall, this work developed a sensitive quantification method for all MVA intermediates, which will enhance our understanding of the role of this pathway in various health and disease conditions. The novel metabolites we discovered warrant further investigations into their biosynthesis and biological functions.

Target analysis of psychoactive drugs in oral fluid by QuEChERS extraction and LC-MS/MS.

This study aimed to validate a modified QuEChERS method, followed by liquid chromatography-tandem mass spectrometry, for the determination of 51 psychoactive substances and screening of 22 ones in oral fluid from electronic dance music party (EDM) attendees. Unstimulated oral fluid was collected in a polypropylene tube and stored in a glass vial at -20 ºC. The sample was extracted with acetonitrile:water and MgSO4/NaOAc, followed by cleanup with primary secondary amine and MgSO4. The effectiveness of the sample storage conditions was shown to be comparable to when the Quantisal™ buffer was used, with no substantial concentration loss (< 15%) for all the substances after up to 72 hours at -20º C. The method was satisfactorily validated, with limits of detection (LOD) and quantification (LOQ) ranging from 0.04 to 0.5 ng/mL and 0.1-1.5 ng/mL, respectively, and was applied to the analysis of 62 real samples. The main substances detected were 3,4-methylenedioxymethamphetamine (MDMA) (<0.5-829 ng/mL) and/or methylenedioxyamphetamine (MDA) (10.1 - 460.6 ng/mL), found in 27 samples, and cocaine (13.0-407.3 ng/mL) and its metabolites (benzoylecgonine 0.17-214.1 ng/mL; ecgonine methyl ester 1.8-150.1 ng/mL) in eight samples. Methamphetamine (11-439 ng/mL) was detected in eight samples, along with MDMA and MDA; eutylone was detected in two cases (4.7 and 24.1 ng/mL) reported as "ecstasy" ingestion. A comparison between self-reported drug use and results of oral fluid analysis indicated that the use of illicit substances is often underreported among EDM attendees, who are often unaware of the substances they consume.

Comparative analysis of Herceptin N-Linked glycosylation by HILIC-FLD and LC-MS/MS methods.

Monoclonal antibodies like Herceptin play a pivotal role in modern therapeutics, with their glycosylation patterns significantly influencing their bioactivity. To characterize the N-glycan profile and their relative abundance in Herceptin, we employed two analytical methods: hydrophilic interaction chromatography with fluorescence detection (HILIC-FLD) for released glycans and liquid chromatography tandem mass spectrometry (LC-MS/MS) for glycopeptides. Our analysis included 21 European Union (EU)-Herceptin lots and 14 United States (US)-Herceptin lots. HILIC-FLD detected 25 glycan species, including positional isomers, revealing comparable chromatographic profiles for both EU and US lots. On the other hand, LC-MS/MS identified 26 glycoforms within the glycopeptide EEQYNSTYR. Both methods showed that a subset of glycans dominated the total abundance. Notably, EU-Herceptin lots with an expiration date of October 2022 exhibited increased levels of afucosylated and high mannose N-glycans. Our statistical comparisons showed that the difference in quantitative results between HILIC-FLD and LC-MS/MS is significant, indicating that the absolute quantitative values depend on the choice of the analytical method. However, despite these differences, both methods demonstrated a strong correlation in relative glycan proportions. This study contributes to the comprehensive analysis of Herceptin's glycosylation, offering insights into the influence of analytical methods on glycan quantification and providing valuable information for the biopharmaceutical industry.

Use of Nonhuman Sera as a Highly Cost-Effective Internal Standard for Quantitation of Multiple Human Proteins Using Species-Specific Tryptic Peptides: Applicability in Clinical LC-MS Analyses.

Quantitation of proteins using liquid chromatography-tandem mass spectrometry (LC-MS/MS) is complex, with a multiplicity of options ranging from label-free techniques to chemically and metabolically labeling proteins. Increasingly, for clinically relevant analyses, stable isotope-labeled (SIL) internal standards (ISs) represent the "gold standard" for quantitation due to their similar physiochemical properties to the analyte, wide availability, and ability to multiplex to several peptides. However, the purchase of SIL-ISs is a resource-intensive step in terms of cost and time, particularly for screening putative biomarker panels of hundreds of proteins. We demonstrate an alternative strategy utilizing nonhuman sera as the IS for quantitation of multiple human proteins. We demonstrate the effectiveness of this strategy using two high abundance clinically relevant analytes, vitamin D binding protein [Gc globulin] (DBP) and albumin (ALB). We extend this to three putative risk markers for cardiovascular disease: plasma protease C1 inhibitor (SERPING1), annexin A1 (ANXA1), and protein kinase, DNA-activated catalytic subunit (PRKDC). The results show highly specific, reproducible, and linear measurement of the proteins of interest with comparable precision and accuracy to the gold standard SIL-IS technique. This approach may not be applicable to every protein, but for many proteins it can offer a cost-effective solution to LC-MS/MS protein quantitation.

Physicochemical properties, metabolomic analysis, antioxidant and lipid - lowering activity of a functional beverage based on cocona (Solanum sessiliflorum Dunal) / Propiedades fisicoquímicas, análisis metabolómico, actividad antioxidante e hipolipemiante de una bebida funcional a base de cocona (Solanum sessiliflorum Dunal)

The physicochemical, microbiological and metabolomics analysis, antioxidant and lipid - lowering effect, and shelf life prediction of a functional beverage based on cocona pul p of SRN9 ecotype was to carry out. According to the results obtained, the beverage complies with all the characteristics of the Peruvian technical standard for juices, nectars and fruit beverages NTP 203.110:2009 and is within the limits established by th e sanitary technical standard NTS N° 071 - MINSA/DIGESA - V.01, with a shelf - life period of 4 months and 1 day. The metabolome regarding bioactive compounds showed the presence of 30 compounds, including several glycosylated flavonols, two flavanols, and two s permidines. Likewise, showed a lipid - lowering effect statistically significant (p < 0.05) about the serum levels of total cholesterol and triglycerides, with a mean reduction of 41.52 mg/dL for total cholesterol levels and 130.80 mg/dL for triglyceride lev els. This beverage could be an alternative for the treatment of atherosclerosis and prevention of cardiovascular diseases.

Se rea lizó el análisis fisicoquímico, microbiológico y metabolómico, efecto antioxidante e hipolipemiante, y vida útil de una bebida funcional a base de cocona ecotipo SRN9. De acuerdo a los resultados, la bebida cumple con las características de la norma técnic a peruana para jugos, néctares y bebidas de frutas NTP 203.110:2009 y se encuentra dentro de los límites establecidos por la norma técnica sanitaria NTS N° 071 - MINSA/DIGESA - V.01, con una vida útil de 4 meses y 1 día. Del perfil metabolómico se identificaro n 30 compuestos, entre ellos varios flavonoles glicosilados, dos flavanoles y dos espermidinas. Asimismo, mostró un efecto hipolipemiante estadísticamente significativo (p < 0,05) sobre los niveles séricos de colesterol total y triglicéridos, con una reduc ción media de 41,52 mg/dL y de 130,80 mg/dL para los niveles de colesterol total y de triglicéridos, respectivamente. Esta bebida podría ser una alternativa para el tratamiento de la aterosclerosis y prevención de enfermedades cardiovasculares.

An LC-MS/MS method for serum cystatin C quantification and its comparison with two commercial immunoassays.

OBJECTIVES: The standardization of cystatin C (CysC) measurement has received increasing attention in recent years due to its importance in estimating glomerular filtration rate (GFR). Mass spectrometry-based assays have the potential to provide an accuracy base for CysC measurement. However, a precise, accurate and sustainable LC-MS/MS method for CysC is still lacking. METHODS: The developed LC-MS/MS method quantified CysC by detecting signature peptide (T3) obtained from tryptic digestion. Stable isotope labeled T3 peptide (SIL-T3) was spiked to control matrix effects and errors caused by liquid handling. The protein denaturation, reduction and alkylation procedures were combined into a single step with incubation time of 1 h, and the digestion lasted for 3.5 h. In the method validation, digestion time-course, imprecision, accuracy, matrix effect, interference, limit of quantification (LOQ), carryover, linearity, and the comparability to two routine immunoassays were evaluated. RESULTS: No significant matrix effect or interference was observed with the CysC measurement. The LOQ was 0.21 mg/L; the within-run and total imprecision were 1.33-2.05 % and 2.18-3.90 % for three serum pools (1.18-5.34 mg/L). The LC-MS/MS method was calibrated by ERM-DA471/IFCC and showed good correlation with two immunoassays traceable to ERM-DA471/IFCC. However, significant bias was observed for immunoassays against the LC-MS/MS method. CONCLUSIONS: The developed LC-MS/MS method is robust and simpler and holds the promise to provide an accuracy base for routine immunoassays, which will promote the standardization of CysC measurement.

Aplicação da Toxicologia Analítica Verde no desenvolvimento de metodologias baseadas em LC-MS para detecção de Novas Substâncias Psicoativas em amostras biológicas / Application of Green Analytical Toxicology to the development of LC-MS-based methodologies for the detection of New Psychoactive Substances in biological samples

No início dos anos 2000, as Novas Substâncias Psicoativas (NPS) emergiram de forma sem precedentes causando uma drástica mudança no mercado de drogas sintéticas mundial. Estas substâncias são sintetizadas para fins ilícitos e mimetizam o efeito psicoativo das drogas tradicionais. Até o momento, mais de 1000 substâncias foram reportadas mundialmente, representando um grande problema de saúde pública principalmente associado ao desconhecimento das suas propriedades toxicológicas. Por este motivo, métodos analíticos para detectar e quantificar estas substâncias em materiais biológicos são importantes nos casos de toxicologia analítica e forense. Contudo, a tendência de reduzir o impacto ambiental destas metodologias tem ganhado popularidade com a Toxicologia Analítica Verde (GAT). Portanto, o objetivo do presente trabalho foi desenvolver novas técnicas analíticas para analisar as principais classes de NPS em amostras biológicas enquanto aplicando os princípios sustentáveis estabelecidos pela GAT. Os resultados obtidos no presente trabalho são apresentados como coletânea de artigos científicos publicados em revistas. Estes estão descritos nos capítulos 4 a 8. No capítulo 4, uma revisão sobre os desafios no desenvolvimento de técnicas de preparo de amostra para fins forenses é abordada com foco no uso das matrizes secas. No Capítulo 5, está descrito a aplicação da microextração líquido-líquido dispersiva para catinonas sintéticas em amostras de sangue total e urina. No capítulo 6, o artigo descreve o desenvolvimento da técnica microextração líquido-líquido homogênea com solventes de hidrofilicidade comutável para canabinoides sintéticos em amostras de plasma. No capítulo 7, a microextração em fase líquida em placas de 96 poços, cunhada extração paralela em membranas artificiais líquidas, foi desenvolvida para diferentes classes de drogas de abuso, incluindo NPS. O capítulo 8 mostra o desenvolvimento de uma extração por eletromembrana também no formato de placa de 96 poços para catinonas sintéticas em amostras de sangue total. Em todos os trabalhos, as técnicas de extração foram desenvolvidas, otimizadas e validadas. Os princípios da GAT foram aplicados de diferentes formas, como reduzindo o volume de amostra, simplificando os procedimentos, evitando o uso de solventes orgânicos, dentre outros. Assim, alternativas mais sustentáveis para a análise de drogas de abuso em amostras biológicas foram apresentadas e estas ajudam a consolidar e difundir o conceito do desenvolvimento de métodos analíticos com consciência ambiental além de fornecer ferramentas para auxiliar o controle das NPS no país

In the early 2000s, New Psychoactive Substances (NPS) emerged and unprecedentedly changed the illicit drug market. These substances are synthesized for illicit purposes and mimic the psychoactive effect of traditional drugs of abuse. To date, more than 1000 substances have been reported worldwide, representing a major public health problem mainly associated with their mostly unknown toxicological properties. In this context, analytical methods able to detect and quantitate these new drugs in biological specimens are important in cases of analytical and forensic toxicology. However, reducing the environmental impact of these methodologies has recently gained popularity with Green Analytical Toxicology (GAT). Therefore, the aim of this work was to develop new analytical techniques to analyze the main classes of NPS in biological samples while applying the environmentally friendly principles established by GAT. The results obtained throughout the development of the present work were split into four papers (chapters 4-8). In chapter 4, a review of common challenges faced during the development of new sample preparation techniques for forensic applications is described focusing on the use of dried matrices. In chapter 5, the application of dispersive liquid-liquid microextraction for synthetic cathinones in whole blood and urine samples is described. In chapter 6, the application of the somewhat recent switchable hydrophilicity solvent-based homogenous liquidliquid microextraction to synthetic cannabinoids in plasma samples is reported. In chapter 7, liquid-phase microextraction in the 96-well plate format, termed parallel artificial liquid membrane extraction, for different classes of drugs of abuse, including NPS, in plasma samples is presented. In chapter 8, an electromembrane extraction in the 96-well plate format for synthetic cathinones in whole blood samples was developed. In this work, sample preparation techniques were developed, optimized and validated. The principles of sustainable chemistry in method development were applied in different ways, such as reducing the sample volume, simplifying procedures, avoiding the use of organic solvents, among others. Thus, greener alternatives were presented for the analysis of drugs of abuse in biological samples and contribute to consolidate and spread this trend of environmental consciousness during method development. Additionally, valuable techniques that can be used in the combat against NPS were provided

Quimioprospecção de cianobactérias brasileiras utilizando metabolômica e ensaios biológicos / Chemoprospecting of Brazilian cyanobacteria using metabolomics and biological assays

Os produtos naturais são uma importante fonte de moléculas com aplicações terapêuticas e biotecnológicas. No entanto, a complexidade inerente às matrizes biológicas e as crescentes taxas de redescoberta de moléculas impõem desafios para a busca por novos compostos bioativos. A exploração de novos espécimes da biodiversidade e a aplicação de ferramentas computacionais são imperativos para a identificação de novas entidades químicas promissoras. Foi proposto catalisar o processo de prospecção química para demonstrar o potencial das cianobactérias brasileiras como fonte de novas moléculas bioativas. Nove linhagens de cianobactérias de água doce/terrestres foram cultivadas, extraídas e fracionadas. Extratos e frações foram testados quanto ao potencial citotóxico contra o microcrustáceo Artemia salina, antiproliferativo contra linhagens celulares de melanoma humano e contra promastigotas de Leishmania (L.) amazonensis. As amostras foram analisadas em paralelo via UPLC-HRMS/MS. Foi criada uma rede molecular através da plataforma GNPS. A desreplicação contou também com o suporte da plataforma DAFdiscovery, ferramenta que, através da fusão de informações dos dados de LC-MS/MS com os metadados contendo informações obtidas dos bioensaios, elenca quais as features se correlacionam com a atividade biológica. A anotação seguida de busca em base de dados foi realizada com auxílio do software SIRIUS. Quatro linhagens de cianobactérias foram selecionadas seguindo essa abordagem devido ao seu potencial ineditismo químico e bioatividade, sendo elas Brasilonema octagenarum, Anagnostidinema amphibium, Nostoc sp. e Komarekiella atlântica

Natural products are an important source of molecules with therapeutic and biotechnological applications. However, the inherent complexity of biological matrices and the increasing rediscovery rates challenge the search for new bioactive compounds. Exploring new specimens of biodiversity and applying computational tools are imperative for identifying promising new chemical entities. In this study, we proposed to catalyze the chemical prospecting process to demonstrate the potential of Brazilian cyanobacteria as a source of new bioactive molecules. Nine strains of freshwater cyanobacteria were cultivated, extracted, and fractionated. Extracts and fractions were tested for cytotoxic potential against the microcrustacean Artemia salina, antiproliferative against human melanoma cell lines, and Leishmania (L.) amazonensis promastigotes. Samples were analyzed in parallel via UPLCHRMS/MS. A molecular network was created using the GNPS platform. Dereplication was guided by DAFdiscovery, a computational tool that, through the fusion of information from LC-MS/MS data with metadata containing information obtained from bioassays, indexed which features correlate with biological activity. Annotation followed by a database search was performed using the SIRIUS software. Brasilonema octagenarum, Anagnostidinema amphibium, Nostoc sp., and Komarekiella atlântica were selected following this approach due to their potential chemical novelty and bioactivity

Evaluation of In Vivo Prepared Albumin-Drug Conjugate Using Immunoprecipitation Linked LC-MS Assay and Its Application to Mouse Pharmacokinetic Study.

There have been many attempts in pharmaceutical industries and academia to improve the pharmacokinetic characteristics of anti-tumor small-molecule drugs by conjugating them with large molecules, such as monoclonal antibodies, called ADCs. In this context, albumin, one of the most abundant proteins in the blood, has also been proposed as a large molecule to be conjugated with anti-cancer small-molecule drugs. The half-life of albumin is 3 weeks in humans, and its distribution to tumors is higher than in normal tissues. However, few studies have been conducted for the in vivo prepared albumin-drug conjugates, possibly due to the lack of robust bioanalytical methods, which are critical for evaluating the ADME/PK properties of in vivo prepared albumin-drug conjugates. In this study, we developed a bioanalytical method of the albumin-conjugated MAC glucuronide phenol linked SN-38 ((2S,3S,4S,5R,6S)-6-(4-(((((((S)-4,11-diethyl-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano [3',4':6,7] indolizino [1,2-b] quinolin-9-yl)oxy)methyl)(2 (methylsulfonyl)ethyl)carbamoyl)oxy)methyl)-2-(2-(3-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)-N-methylpropanamido)acetamido)phenoxy)-3,4,5-trihydroxytetra-hydro-2H-pyran-2-carboxylic acid) as a proof-of-concept. This method is based on immunoprecipitation using magnetic beads and the quantification of albumin-conjugated drug concentration using LC-qTOF/MS in mouse plasma. Finally, the developed method was applied to the in vivo intravenous (IV) mouse pharmacokinetic study of MAC glucuronide phenol-linked SN-38.

Pharmacokinetics and pharmacodynamics of Astragali Radix-Corni Fructus Herb-pair Extract, in kidney-yin deficiency model

Abstract To investigate the pharmacokinetics and pharmacodynamics of Astragali Radix-Corni Fructus herb-pair in kidney-yin deficiency model, which was made by continuously oral gavage of thyroxine. A simple and rapid LC-MS/MS method was developed and validated for the determination of loganin and morroniside in rat plasma and used for the pharmacokinetics study. The kidney-yin deficiency significantly changed the AUC(0-∞), Cmax and CLz/F of loganin and morroniside. The T1/2z of morroniside increased significantly in the kidney-yin deficiency rats. For the pharmacodynamics study, the liver index, kidney index, and ALT, TBIL, UREA, CREA level in the kidney-yin deficiency mice were examined. The herb-pair had been proved to be effective for the treatment of kidney-yin deficiency by affecting the liver, kidney, ALT, UREA and CREA, which showed positively correlated with the dose. The pharmacokinetics and pharmacodynamics studies in the pathological status could offer more valuable information for the future application of Astragali Radix-Corni Fructus herb-pair.