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Objective To understand the HIV infection risk perception bias and its related influencing factors among young men who have sex with men (MSM) in Shandong Province, so as to provide reference for making feasible HIV health education plans. Methods From April to July, 2022, young MSM were recruited in six cities in Shandong province, and a questionnaire survey was conducted and blood samples were collected to collect demographic characteristics, HIV risk perception and risk behavior of MSM. Logistic regression model was used to analyze the influencing factors of HIV infection risk perception bias among young MSM. Results A total of 978 MSM were investigated, of which 85%(831/978) were over 20 years old, 97.6%(955/978) were unmarried/divorced or widowed, 61.1%(598/978) were college educated, 2.6% (25/978) were positive for HIV antibody and 3.6%(35/978) for syphilis antibody. 47.1%(461/978) had HIV infection risk perception bias, of which 54.0%(249/461) underestimate the risk and 46.0%(212/461) overestimate the risk. Logistic regression analysis showed that unmarried/divorced/widowed (OR = 11.693, 95%CI: 1.546-88.407) and having no or low risk of new drugs (OR = 2.041, 95%CI: 1.477-2.825) were the risk factors for underestimating the risk. Household registration in Shandong province (OR = 2.618, 95%CI: 1.397-4.902), college education or above (OR = 1.728, 95%CI: 1.206-2.475), homosexuality (OR = 2.532, 95%CI: 1.093-5.845), having general or high risk of new drugs(OR = 8.323, 95%CI: 4.602-15.052), who had not received AIDS intervention (OR = 2.288, 95%CI: 1.224-4.292) and had not taken preventive drugs before exposure (OR = 11.905, 95%CI: 3.663-38.462) were the risk factors for overestimating the risk. Conclusion HIV infection risk perception bias among young MSM in Shandong Province is high, and HIV risk behaviors are widespread. It is necessary to strengthen the education of MSM who have low self-rated HIV infection risk but have high-risk behaviors, improve risk awareness and reduce the occurrence of dangerous behaviors. [ABSTRACT FROM AUTHOR]

Liquid chromatography mass spectrometry based methods provide powerful tools for protein analysis. Cytochromes P450 (CYPs), the most important drug metabolic enzymes, always exhibit sex-dependent expression patterns and metabolic activities. To date, analysis of CYPs based on mass spectrometry is still facing critical technical challenges due to the complexity and diversity of CYP isoforms besides lack of corresponding standards. The aim of present work consisted in developing a label-free qualitative and quantitative strategy for endogenous proteins, and then applying to the gender-difference study for CYPs in rat liver microsomes (RLMs). Initially, trypsin digested RLM specimens were analyzed by the nanoLC-LTQ-Orbitrap MS/MS. Skyline, an open source and freely available software for targeted proteomics research, was then used to screen the main CYP isoforms in RLMs under a series of criteria automatically, and a total of 40 and 39 CYP isoforms were identified in male and female RLMs, respectively. More importantly, a robust quantitative method in a tandem mass spectrometry-multiple reaction mode (MS/MS-MRM) was built and optimized under the help of Skyline, and successfully applied into the CYP gender difference study in RLMs. In this process, a simple and accurate approach named ‘Standard Curve Slope” (SCS) was established based on the difference of standard curve slopes of CYPs between female and male RLMs in order to assess the gender difference of CYPs in RLMs. This presently developed methodology and approach could be widely used in the protein regulation study during drug pharmacological mechanism research. [ABSTRACT FROM AUTHOR]

Ethnopharmacological relevance Intestinal microflora plays crucial roles in modulating pharmacokinetic characteristics and pharmacological actions of active ingredients in traditional Chinese medicines (TCMs). However, the exact impact of altered intestinal microflora affecting the biotransformation of TCMs remains poorly understood. Aims of the study This study aimed to reveal the specific enterobacteria which dominate the metabolism of panax notoginseng saponins (PNSs) via exploring the relationship between bacterial community structures and the metabolic profiles of PNSs. Materials and methods 2, 4, 6-Trinitrobenzenesulphonic acid (TNBS)-challenged and pseudo germ-free (pseudo GF) rats, which prepared by treating TNBS and antibiotic cocktail, respectively, were employed to investigate the influence of intestinal microflora on the PNS metabolic profiles. Firstly, the bacterial community structures of the conventional, TNBS-challenged and pseudo GF rat intestinal microflora were compared via 16S rDNA amplicon sequencing technique. Then, the biotransformation of protopanaxadiol-type PNSs (ginsenoside Rb1, Rb2 and Rd), protopanaxatriol-type PNSs (ginsenoside Re, Rf, Rg1 and notoginsenoside R1) and Panax notoginseng extract (PNE) in conventional, TNBS-challenged and pseudo GF rat intestinal microbiota was systematically studied from qualitative and quantitative angles based on LC-triple-TOF/MS system. Besides, glycosidases (β-glucosidase and β-xylosidase), predominant enzymes responsible for the deglycosylation of PNSs, were measured by the glycosidases assay kits. Results Significant differences in the bacterial community structure on phylum, class, order, family, and genera levels were observed among the conventional, TNBS-challenged and pseudo GF rats. Most of the metabolites in TNBS-challenged rat intestinal microflora were identified as the deglycosylation products, and had slightly lower exposure levels than those in the conventional rats. In the pseudo GF group, the peak area of metabolites formed by loss of glucose, xylose and rhamnose was significantly lower than that in the conventional group. Importantly, the exposure levels of the deglycosylated metabolites were found have a high correlation with the alteration of glycosidase activities and proteobacteria population. Several other metabolites, which formed by oxidation, dehydrogenation, demethylation, etc , had higher relative exposure in pseudo GF group, which implicated that the up-regulation of Bacteroidetes could enhance the activities of some redox enzymes in intestinal microbiota. Conclusion The metabolism of PNSs was greatly influenced by intestinal microflora. Proteobacteria may affect the deglycosylated metabolism of PNSs via regulating the activities of glycosidases. Besides, up-regulation of Bacteroidetes was likely to promote the redox metabolism of PNSs via improving the activities of redox metabolic enzymes in intestinal microflora. [ABSTRACT FROM AUTHOR]

High rates of relapse and poor prognosis confer an urgent need for novel therapeutic agents for B cell non-Hodgkin lymphomas (B-NHLs). Herein, we describe a human IgG-like anti-CD79b/CD3 bispecific antibody (IBI38D9-L) that selectively depletes antigen-positive malignant B cells as an alternative treatment option for relapsed or refractory NHL patients. The antitumor activity and mechanism of action of IBI38D9-L were investigated in vitro using B-NHL cell lines and human primary effector cells and in vivo using xenograft models reconstituted with human PBMCs (peripheral blood mononuclear cells). Pharmacokinetic (PK) properties and preclinical toxicology were evaluated in cynomolgus monkeys and HSC-NPG mice. IBI38D9-L exerted potent B cell killing as well as T cell activation and proliferation in a tumor cell-dependent manner in vitro and was active against B-NHL cell lines with various CD79b expression levels. Subcutaneous xenograft tumors in NOG mice engrafted with human PBMCs were eradicated by IBI38D9-L treatment. Moreover, IBI38D9-L-treated mice showed a strong infiltration of activated T cells. In HSC-NPG mice, IBI38D9-L resulted in potent B cell depletion in peripheral blood and induced only slight body weight loss and cytokine release syndrome without significant toxicological findings. In cynomolgus monkeys, IBI38D9-L was well tolerated with good pharmacokinetic profiles. Collectively, these preclinical efficacy and safety data provide strong scientific rationales for using anti-CD79b/CD3 bispecific antibody as a promising therapeutic agent for B cell malignancies. [ABSTRACT FROM AUTHOR]

Data concerning the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in asymptomatic and paucisymptomatic patients are lacking. We report a 3-family cluster of infections involving asymptomatic and paucisymptomatic transmission. Eight of 15 (53%) members from 3 families were confirmed with SARS-CoV-2 infection. Of 8 patients, 3 were asymptomatic and 1 was paucisymptomatic. An asymptomatic mother transmitted the virus to her son, and a paucisymptomatic father transmitted the virus to his 3-month-old daughter. SARS-CoV-2 was detected in the environment of 1 household. The complete genomes of SARS-CoV-2 from the patients were > 99.9% identical and were clustered with other SARS-CoV-2 sequences reported from China and other countries. [ABSTRACT FROM AUTHOR]

Aims: To investigate the effects of sodium‐glucose co‐transporter‐2 (SGLT2) inhibitors vs. dipeptidyl peptidase‐4 (DPP‐4) inhibitors on renal function preservation (RFP) using real‐world data of patients with type 2 diabetes in Japan, and to identify which subgroups of patients obtained greater RFP benefits with SGLT2 inhibitors vs. DPP‐4 inhibitors. Methods: We retrospectively analysed claims data recorded in the Medical Data Vision database in Japan of patients with type 2 diabetes (aged ≥18 years) prescribed any SGLT2 inhibitor or any DPP‐4 inhibitor between May 2014 and September 2016 (identification period), in whom estimated glomerular filtration rate (eGFR) was measured at least twice (baseline, up to 6 months before the index date; follow‐up, 9 to 15 months after the index date) with continuous treatment until the follow‐up eGFR. The endpoint was the percentage of patients with RFP, defined as no change or an increase in eGFR from baseline to follow‐up. A proprietary supervised learning algorithm (Q‐Finder; Quinten, Paris, France) was used to identify the profiles of patients with an additional RFP benefit of SGLT2 inhibitors vs. DPP‐4 inhibitors. Results: Data were available for 990 patients prescribed SGLT2 inhibitors and 4257 prescribed DPP‐4 inhibitors. The proportion of patients with RFP was significantly greater in the SGLT2 inhibitor group (odds ratio 1.27; P = 0.01). The Q‐Finder algorithm identified four clinically relevant subgroups showing superior RFP with SGLT2 inhibitors (P < 0.1): no hyperlipidaemia and eGFR ≥79 mL/min/1.73 m2; eGFR ≥79 mL/min/1.73 m2 and diabetes duration ≤1.2 years; eGFR ≥75 mL/min/1.73 m2 and use of antithrombotic agents; and haemoglobin ≤13.4 g/dL and LDL cholesterol ≥95.1 mg/dL. In each profile, glycaemic control was similar in the two groups. Conclusion: SGLT2 inhibitors were associated with more favourable RFP vs. DPP‐4 inhibitors in patients with certain profiles in real‐world settings in Japan. [ABSTRACT FROM AUTHOR]

Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS) is an excellent analytical technique for rapid analysis of a variety of molecules with straightforward sample pretreatment. The performance of MALDI‐TOF MS is largely dependent on matrix type, and the development of novel MALDI matrices has aroused wide interest. Herein, we devoted to seek more robust MALDI matrix for herbal saponins than previous reported, and ginsenoside Rb1, Re, and notoginsenoside R1 were used as model saponins. At the beginning of the present study, 2,5‐dihydroxybenzoic acid (DHB) was found to provide the highest intensity for saponins in four conventional MALDI matrices, yet the heterogeneous cocrystallization of DHB with analytes made signal acquisition somewhat "hit and miss." Then, graphene oxide (GO) was proposed as an auxiliary matrix to improve the uniformity of DHB crystallization due to its monolayer structure and good dispersion, which could result in much better shot‐to‐shot and spot‐to‐spot reproducibility of saponin analysis. The satisfactory precision further demonstrated that minute quantities of GO (0.1 μg/spot) could greatly reduce the risk of instrument contamination caused by GO detachment from the MALDI target plate under vacuum. More importantly, the sensitivity and linearity of the standard curve for saponins were improved markedly by DHB‐GO composite matrix. Finally, the application of detecting the Rb1 in complex biological sample was exploited in rat plasma and proved it applicable for pharmacokinetic study quickly. This work not only opens a new field for applications of DHB‐GO in herbal saponin analysis but also offers new ideas for the development of composite matrices to improve MALDI MS performance. [ABSTRACT FROM AUTHOR]

The great hurdles related with matrix-assisted laser desorption/ionization (MALDI) analysis are inhomogeneous crystallization, poor reproducibility, and low sensitivity. To effectively improve the performance of MALDI mass spectrometry (MS), graphene oxide (GO) was first utilized as an auxiliary matrix of the conventional matrices, including 2,5-dihydroxybenzoic acid (DHB), α-cyano-4-hydoxycyanocinnamic acid (CHCA), 2,4,6-trihydroxyacetophenone (THAP), and 3,5-dimethoxy-4-hydroxycinnamic acid (SA), for the analysis of small molecules and biological macromolecules on different MALDI MS systems. The results revealed that the DHB-GO composite matrix could provide much superior crystal homogenization, better reproducibility, higher sensitivity, and more excellent linearity for the statins' tissue imaging on iMScope than the single-use DHB matrix. Moreover, the DHB-GO dramatically improved the spot-to-spot and shot-to-shot reproducibility, crystal homogenization, sensitivity, and linearity of MALDI-TOF MS for statins' analysis in dried droplet. The capability of THAP on the analysis of lipids, similarly, could be greatly enhanced by the combined use of GO. THAP-GO composite matrix was expected to be widely used in the MALDI MS-based liposome studies. It was also found that CHCA-GO could provide superior analytical performance for peptides. The sensitivity and reproducibility of intact proteins could be greatly improved by SA-GO composite matrix. More importantly, the better reproducibility produced by the composite matrices sufficiently indicated that low concentration (0.1 mg mL−1) of GO almost did not cause contamination to MALDI MS system. Thus, GO was proved to be a versatile auxiliary matrix for the MALDI MS-based routine analysis of small molecules and biological macromolecules.ᅟ [ABSTRACT FROM AUTHOR]

When developing a quantitative assay for exogenous or endogenous compounds, guidelines for method validation normally recommend that the biological specimens should be prepared in corresponding authentic matrices, yet “analyte-free authentic matrices” is in general not available. It is generally known that GSH and CYS are endogenous compounds and present in both prokaryotes and eukaryotes. Herein, an efficient approach for the quantitative analysis of endogenous substances in biological specimens was developed, and glutathione (GSH) & cysteine (CYS) were chosen as model endogenous substances. Activated carbon (AC), a common adsorbent for the adsorption of environmental pollutants, was used to remove the endogenous GSH and CYS and prepare “GSH&CYS-free biological matrix”. The endogenous GSH and CYS in mouse plasma, blood and liver homogenate were found can be almost removed via incubating with 100 mg of AC for 2 h. After optimizing the derivatization reagents, internal standard and analytical parameters, a reliable quantitative assay of GSH and CYS in mouse plasma, blood and liver homogenate was developed and validated on LC-ESI-MS/MS using corresponding AC-adsorbed mouse biological matrices. The validation results indicated that the developed method provided suitable accuracy, sensitivity, specificity and high throughput for the analysis of GSH and CYS. Finally, the developed LC-ESI-MS/MS assay was successfully applied to measure the concentrations of GSH and CYS in liver injury mice. The presently developed methodology could be widely applied in the quantitative analysis of endogenous compounds in various complex mixtures such as biological, herbal and environmental samples. [ABSTRACT FROM AUTHOR]

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry imaging (MALDI-TOF-MSI) has received considerable attention in recent years since it allows molecular mapping of diverse bimolecular in animal/plant tissue sections, although some barriers still exist in absolute pixel-to-pixel quantification. Octreotide, a synthetic somatostatin analogue, has been widely used to prevent gastrointestine bleeding in the clinic. The aim of the present study is to develop a MALDI-TOF-MSI method for quantitatively visualizing spatial distribution of octreotide in mouse tissues. In this process, a structurally similar internal standard was spotted onto tissue section together with matrix solution to minimize signal variation and give excellent quantitative results. The 2,5-dihydroxybenzoic acid was chosen as the most suitable matrix via comparing the signal/noise generated by MALDI-TOF-MSI after cocrystallization of octreotide with different matrix candidates. The reliability of MALDI-TOF-MSI, with respect to linearity, sensitivity and precision, was tested via measuring octreotide in fresh tissue slices at different concentrations. The validated method was then successfully applied to visualize the distribution of octreotide in mouse tissues after oral administration of octreotide at 20 mg/kg. The results demonstrated that MALDI-TOF-MSI could not only clearly visualize the spatial distribution of octreotide, but also make the calculation of the key pharmacokinetic parameters (T max and t 1/2 ) possible. More importantly, the tissue concentration-time curves of octreotide determined by MALDI-TOF-MSI agreed well with those measured based on LC–MS/MS.These findings illustrate the potential of MALDI-TOF-MSI in pharmacokinetic profiling during drug development. [ABSTRACT FROM AUTHOR]

Application of imaging mass spectrometry in drug pharmacokinetics remains challenging due to its weak quantitative capability. Herein, an imaging mass microscope (iMScope), equipped with an optical microscope, an atmospheric pressure ion-source chamber for matrix-assisted laser desorption/ionization (AP-MALDI) and a hybrid quadrupole ion trap time-of-flight (QIT-TOF) analyzer, was first validated and applied to visualize drug disposition in vivo . The distribution and elimination rate of the therapeutic peptide octreotide, a long-acting analogue of the natural hormone somatostatin, was first calculated based on the data determined by iMScope system combining a novel relative exposure strategy. Microspotted pixel-to-pixel quantitative iMScope provided a relative amount of octreotide presented in a thin stomach/intestinal section while preserving its original spatial distribution. The images of dosed mouse stomach clearly demonstrated the transport process of octreotide from the mucosal layer to the muscle side. More importantly, octreotide was found to eliminate from the intestines rapidly, the absorption peak time (T max ) appeared at 40 min and the half-life time (t 1/2 ) was calculated as 37.7 min according to the elimination curves. Comparisons to the LC-MS/MS data adequately indicated that the quantification approach and methodology based on the iMScope was reliable and practicable for drug pharmacokinetic study. [ABSTRACT FROM AUTHOR]

In this contribution, the metabolic and pharmacokinetic characteristics for the therapeutic peptide HM-3 were investigated using LC-Q-TOF/MS and LC–MS/MS systems combing a fast biological sample processing method. According to the accurate MS 1 and MS 2 data generated by LC-Q-TOF/MS, a total of 6 metabolites in rats were detected and tentatively identified as the degradation products which formed by successive loss of amino acid from HM-3. The structures of the 2 main metabolites (M1 and M2) were confirmed by comparing the chromatographic and mass spectrographic characteristics with the corresponding synthetic standards. Then, an absolute quantitative analysis method based on LC–MS/MS system was built and fully validated with respect to linearity, sensitivity, accuracy, precision, matrix effect, stability, etc . The results indicated that HM-3, M1 and M2 were linear in peak area ratios over the concentration range of 0.5–200.0 ng/mL with a correlation coefficient > 0.99. The intra-day and inter-day precisions (RSD%) were less than 15%, and the accuracy was below 10% in terms of RE%. The validated method was then successfully applied to the studies of preclinical pharmacokinetics for HM-3. [ABSTRACT FROM AUTHOR]

Ziyuglycoside II, one of the major effective ingredients of Sanguisorba officinalis L., had various pharmacological activities including anticancer, anti-inflammation and anti-oxidation, etc . Better understanding of the pharmacology and toxicology of ziyuglycoside II requires the detailed elucidation of its biologic fates in vivo . Herein, the metabolic fate of ziyuglycoside II in rats was investigated based on liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (LC-Q-TOF/MS). To accelerate and simplify the process of metabolite identification from complicated biological matrix, the sectional multiple filtering (SMF) scheme was designed according to the relationship among the molecular weight (MW), mass defect (MD) and retention time (t R ) of the metabolites. SMF-I (MW: 700–850 Da, MD: 0.40–0.45 Da, t R : 4.0–10.0 min), SMF-II (MW: 550–700 Da, MD: 0.30–0.40 Da, t R : 6.0–14.0 min) and SMF-III (MW: 400–550 Da, MD at 0.25–0.35 Da, t R at 9.5–16.0 min) were built and utilized to screen phase II conjugations and phase I redox metabolites and deglycosylated derivatives, respectively. As a result, dozens of metabolites, including glucuronic conjugates, hydroxylation, oxidization, dehydration and deglycosylation products, were rapidly discovered, classified and structural identified in rat urine and feces based on SMF scheme and accurate MS 1 /MS 2 information. Obviously, the SMF technique showed superior efficiency and selectivity in ziyuglycoside II metabolite identification. More importantly, SMF would find its extensive application in, but not limited to, the metabolic study for single drug or homologous compounds in traditional Chinese medicine. [ABSTRACT FROM AUTHOR]

Ziyuglycoside I is one of the major active ingredients in Sanguisorba officinalis , a popular medicinal plant in China. In the present study, the metabolites of ziyuglycoside I in rat liver microsome and intestinal flora were identified and structurally characterized, and the metabolic rules were summed based on the LC–Q-TOF/MS system. Then, the metabolites in rat excreta samples were rapidly screened and identified according to the in vitro metabolic rules. Finally, ziyuglycoside I was incubated with fresh liver/lung/kidney/stomach homogenates to further explore the source of the metabolites and reveal the possible metabolic organs involved. Four metabolites in liver microsome were identified as M0-Glu, M0-CH 2 OH, M0-Glu + CH 3 , M0-Glu-Ara + CH 3 . In intestinal flora incubation system, 6 degradation products including M0-Glu-Ara + O, M0-Ara, M0-Glu-COOH, M0-Glu, M0-Glu-Ara + O and M0-Ara + H 2 O were tentatively identified by interpretation of their accurate MS 1 and MS 2 data. Fifteen metabolites in rat urine and feces were identified, and most of the metabolites were attributed to the transformation in liver microsome and intestinal flora. Specifically, more than a dozen of new metabolites were identified in rat fresh tissues, and ziyuglycoside II was confirmed as the major metabolite in rats. [ABSTRACT FROM AUTHOR]

Pidotimod, ( R )-3-[( S )-(5-oxo-2-pyrrolidinyl) carbonyl]-thiazolidine-4-carboxylic acid, was frequently used to treat children with recurrent respiratory infections. Preclinical pharmacokinetics of pidotimod was still rarely reported to date. Herein, a liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was developed and validated to determine pidotimod in rat plasma, tissue homogenate and Caco-2 cells. In this process, phenacetin was chosen as the internal standard due to its similarity in chromatographic and mass spectrographic characteristics with pidotimod. The plasma calibration curves were established within the concentration range of 0.01–10.00 μg/mL, and similar linear curves were built using tissue homogenate and Caco-2 cells. The calibration curves for all biological samples showed good linearity (r > 0.99) over the concentration ranges tested. The intra- and inter-day precision (RSD, %) values were below 15% and accuracy (RE, %) was ranged from −15% to 15% at all quality control levels. For plasma, tissue homogenate and Caco-2 cells, no obvious matrix effect was found, and the average recoveries were all above 75%. Thus, the method demonstrated excellent accuracy, precision and robustness for high throughput applications, and was then successfully applied to the studies of absorption in rat plasma, distribution in rat tissues and intracellular uptake characteristics in Caco-2 cells for pidotimod. [ABSTRACT FROM AUTHOR]

Notoginsenosides, the main active gradients of Chinese traditional medicine Panax notoginseng, possesses a variety of biological activities including antioxidant property, anti-hyperglycemic, anti-obese, etc . However, pharmacokinetic evaluation for notoginsenosides is still a formidable task due to their low concentrations and complex components in vivo . The summation of this work generated a rapid and sensitive method for quantitative analysis of multi-notoginsenoside in rat plasma based on ultra fast liquid chromatographic-tandem mass spectrometric. After liquid–liquid extraction by n -butanol, notoginsenoside R1, Rg3, Rd, Rg2, Rb2, Rf, Rg1, Rb1 and Re were simultaneously monitored in negative ionization mode after separating on a Thermo ODS C 18 column (5 mm 50 mm × 2.1 mm) by a binary gradient elution, and all compounds were analyzed within 9 min. Multiple reaction monitoring (MRM) was performed as follows: R1 ( m / z 967.7 → 637.4), Rg3 ( m / z 819.6 → 621.4), Rd ( m/z 981.6 → 783.5), Rg2 ( m / z 819.6 → 475.4), Rb2 ( m / z 1113.4 → 783.4), Rf ( m / z 835.6 → 475.4), Rg1 ( m / z 835.6 → 637.6), Rb1 ( m / z 1143.7 → 945.6), Re ( m / z 981.6 → 637.4), internal standard (digoxin, m / z 815.5 → 779.4). Validation parameters (linearity, sensitivity, intra-and inter-assay precision and accuracy, recovery and matrix effect) were within acceptable ranges and biological extracts were stable during the entire storing and preparing process. This UFLC–MS/MS approach was further validated by being applied to the pharmacokinetic study for P. Notoginseng extract in rats, and the pharmacokinetic parameters were calculated by Winolin software. Thus, the presently developed methodology was simple, robust, accurate, precise, and would be useful for the pharmacokinetic studies for all kinds of notoginsenosides and other herbal saponins. [ABSTRACT FROM AUTHOR]

This study provided a novel and generally applicable method to determine ziyuglycoside I and ziyuglycoside II in rat plasma based on liquid chromatography with tandem mass spectrometry. A single step of liquid-liquid extraction with n-butanol was utilized, and ginsenoside Rg3 was chosen as internal standard. Final extracts were analyzed based on liquid chromatography with tandem mass spectrometry. Chromatographic separation was achieved using a Thermo Golden C18 column, and the applied gradient elution program allowed for the simultaneous determination of two ziyuglycosides in a one-step chromatographic separation with a total run time of 10 min. The fully validated methodology for both analytes demonstrated high sensitivity (the lower limit of quantitation was 2.0 ng/mL), good accuracy (% RE ≤ ± 15) and precision (% RSD ≤ 15). The average recoveries of both ziyuglycosides and internal standard were all above 75% and no obvious matrix effect was found. This method was then successfully applied to the preclinical pharmacokinetic studies of ziyuglycoside I and ziyuglycoside II. The presently developed methodology would be useful for the preclinical and clinical pharmacokinetic studies for ziyuglycoside I and ziyuglycoside II. [ABSTRACT FROM AUTHOR]