Duanyun Si

Tianjin Yugen MedTech

Ethnopharmacological relevance Ilicis Rotundae Cortex (IRC), the dried barks of Ilex rotunda Thunb. (Aquifoliaceae), has been used for the prevention or treatment of colds, tonsillitis, dysentery, and gastrointestinal diseases in folk medicine due to its antibacterial and anti-inflammatory effects. However, there is no report about the intestinal a...

Context Rotundic acid (RA), a plant-derived pentacyclic triterpene acid, has been reported to possess extensive pharmacological activities. The poor bioavailability limits its further development and potential clinic application. Objective To clarify the potential mechanism for poor oral bioavailability. Materials and methods The single-dose phar...

Rotundic acid (RA), an ursane-type pentacyclic triterpene acid isolated from the dried barks of Ilex rotunda Thunb. (Aquifoliaceae), possesses diverse bioactivities. To further study its pharmacokinetics, a simple and sensitive liquid chromatography with triple quadrupole mass spectrometry (LC-QqQ-MS/MS) method was developed and validated to quanti...

FIM protein, which consists of 155 amino acids, was developed as a novel GLP‐1 analog to reduce blood glucose, and pharmacodynamic results showed that it had a certain effect when used in treating Alzheimer's disease. The molecular weight of FIM is 16304Da. In theory, the concentration of FIM in biological samples should be determined by the LBA me...

1. The objective of this study was to clarify the species differences of pharmacokinetics of Y101 (N-[N-benzoyl-O-(2-dimethylaminoethyl)-l-tyrosyl]-l-phenylalaninol hydrochloride), a derivative of herbal ingredient with anti-HBV hepatitis activity, in rats, dogs, monkeys and humans. 2. The metabolic stability and metabolite identification studies u...

Insulin is an effective therapeutic for diabetes, and the level of insulin in vivo is directly related to the health of diabetic patients. Traditionally, the concentrations of insulin in vivo were determined by the RIA method. In this study, we developed an LC‐MS/MS method for the quantification of human insulin in dog plasma and directly compared...

A simple, sensitive and selective LC-MS/MS method was developed for the quantitative analysis of liraglutide and validated in rat plasma. Human insulin was used as the internal standard. After a simple protein precipitation step, liraglutide was chromatographically separated using an InertSustain Bio C18 column with mobile phases comprising acetoni...

A simple, sensitive and selective LC-MS/MS method for quantitative analysis of human insulin was developed and validated in dog plasma. Insulin glargine was used as the internal standard. After a simple step of solid-phase extraction, the chromatographic separation of human insulin was achieved by using InertSustain Bio C18 column with a mobile pha...

The gold nanoclusters (Au-NCs) have emerged for delivery of various payloads such as small molecular drug and big molecular proteins due to their low immunogenicity, quick clearance and good biocompatibility. Even though they have shown great prospective in biomedical area, there are also some security problems which should be investigated further...

Bentysrepinine (Y101), a derivative of repensine (a compound isolated from Dichondrarepens Forst), is a novel phenyalanine dipeptide inhibiting DNA-HBV and cccDNA activities and is currently under development for the treatment of hepatitis B virus (HBV)-infected hepatitis. Our previous study implied that there might be an existence of extensive met...

The previous investigation has proved that their existed pharmacokinetic difference between the different crystal forms of the polymorphic drugs after oral administration. However, no systemic investigations have been made on the change of this pharmacokinetic difference, resulted either from the physiological or from the pathological factors. In t...

Deoxyglycychloxazol (TY501) is a glycyrrhetinic acid derivative which exhibits high anti-inflammatory activities and reduced pseudoaldosteronism compared to glycyrrhetinic acid. In this study, a sensitive and rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was established for the quantitation of TY501 in rat plasma. Plasma sa...

Many herbal medicines and drugs are available in the clinic as potent hepatoprotective agents for the treatment of commonly occurring liver diseases. Recently, herbal medicines such as silymarin and curcumin have gained more attention and popularity for the treatment of various liver diseases because of their safety and efficacy profiles. Some of t...

LAT1 overexpressed on membrane of various tumor cells, is a are potential targets for tumor-targeting therapy. This study aimed to develop a LAT1-mediated chemotherapeutic agents. Here we screened about 7 large neutral amino acid modified doxorubicin. After screening, the aspartate modified doxorubicin (Asp-DOX) showed the highest affinity (Km = 41...

Aim To develop a simple, rapid and accurate analysis method for determination of chiral ibuprofen in Beagle dog plasma. Method The plasma sample was submitted to liquid-liquid extraction u-sing hexane/isopropanol (95: 5, V/V), with ketopro-fen as the internal standard (IS). The separation was accomplished in a Lux 5u Cellulose-3 (250 mm 4. 6 mm, 5...

Clevidipine, a vascular selective calcium channel antagonist of the dihydropyridine class, is rapidly metabolized by ester hydrolysis because of incorporation of an ester linkage into the drug molecule. To characterize its pharmacokinetic profiles in dogs, a simple, rapid and sensitive liquid chromatography–tandem mass spectrometry (LC–MS/MS) metho...

Objective: To study the in vivo metabolic pathways of liquiritin (LQ) in rats. Methods: An HPLC-QTRAP-MS method was established and applied to identify the metabolites of LQ in bile, urine, feces, and plasma after ig administration of LQ (300 mg/kg) to rats. Results: A total of nine metabolites were found in rats. The major metabolic pathway of LQ...

Aildenafil, 1-{[3-(6, 7-dihydro-1-methyl-7-oxo-3-propyl-1H-pyrazolo [4, 3-d] primidin-5-yl)-4-ethoxyphenyl] sulfonyl}-cis-3, 5-dimethylpiperazine, a phosphodiesterase type V enzyme inhibitor (PDE5I), is under development for treatment of erectile dysfunction (ED). The purpose of this study was to elucidate metabolism of aildenafil in vivo in rats a...

A significant number of organic carboxylic acids have been shown to influence the absorption and distribution of drugs mediated by organic anion transporters (OATs). In this study, uptake experiments were performed to assess the inhibitory effects of cinnamic acid, ferulic acid, oleanolic acid, deoxycholic acid, and cynarin on hOAT1, hOAT3, hOATP1B...

Drug-drug interaction is one of the most important preclinical investigation directions. It may have serious impact on drug absorption, distribution and elimination through membrane transporters. Liquid chromatography/Tandem mass spectrometry (LC/MS/MS) could be used to investigate drug-drug interaction in vitro. A sensitive LC/MS/MS method was est...

Objective: To study the in vivo metabolic pathways of 3-acetyl-11-keto-β-boswellic acid (AKBA) in rats. Methods: An HPLC-QTRAP-MS method was applied to identifying the metabolites of AKBA in bile, urine, and feces after ig administration of AKBA 60 mg/kg to rats. Results: A total of 15 metabolites were found in rats. The major metabolic pathways of...

In this study, a simple and sensitive LC/MS/MS method was developed and validated for the determination of arctigenin in rat plasma. The MS detection was performed using multiple reaction monitoring at the transitions of m/z 373.2 → 137.3 for arctigenin and m/z 187.1 → 131.0 for psoralen (internal standard) with a Turbo IonSpray electrospray in pos...

Polymeric micelles have been proven to be a promising nano-sized system for drug delivery. Understanding its in vivo behaviors at the whole body, tissue and cellular levels is critical for translating this drug delivery system into clinical practice. In this study, the 14.5nm micelles made of polyethylene glycol-phosphatidylethanolamine (PEG-PE) fo...

Objective: To research the permeation of acetyl-11-keto-beta-boswellic acid (AKBA) through blood-brain barrier. Methods: MDCK-MDR1 cell monolayer model was used to study the bi-directions transport of AKBA; the concentration of AKBA was measured by LC-MS/MS and apparent permeability coefficient (Papp) was calculated. Results: The Papp of caffeine a...

Objective: To study the mechanisms of absorption and transport of 3-acetyl-11-keto-β-boswellic acid (AKBA) from Boswellia carterif in Caco-2 cell, MDCK-MDR1, and MDCK-Wild cell models. Methods: The Caco-2, MDCK-MDR1, and MDCK-Wild cell monolayer models were used to study the bi-directional transport of AKBA in apical (AP)→basal (BL) or BL→AP; The c...

A sensitive, rapid, and specific liquid chromatography/tandem mass spectrometry assay has been established and validated for the quantitation of evodiamine and evodine in Beagle dog plasma. Plasma samples of 0.2 ml were processed by liquid-liquid extraction with n-hexane/ethyl acetate (2:1, v/v). Chromatographic separations were done on a Symmetry...

More and more herbal medicines are found to be the substrates of drug transporters. In this paper, chromatography/tandem mass spectrometry (LC/MS/MS) combined with radioisotope method was used for the quantification of catalpol, a traditional Chinese medicine, to study the affinity relationship between herbal medicines and transporters. Catalpol up...

Objective In order to analyze the active components in the extracts from Kaki Folium (KF), quantitative metabolomics approach was adopted to investigate the number of active components existing among the different extracts and their variation.MethodsLC-MS method was established for the quantitative determination of the active components taking the...

A simple, robust, and sensitive high-performance liquid chromatography tandem mass spectrometry method was developed and validated for determination of a new nonpeptidic glucose-like peptide-1 receptor (GLP-1R) agonist 1,3-bis(4-((p-butoxycarbonyl)amino)benzamido)-2,4-bis(m-methoxy-p-(thiophene-2-methanoyl)phenyl)-cyclobutane-1,3-dicarboxylic acid...

Over the past few years, nanoscale Chinese medicine has become one of focuses in modern Chinese medicine research. There is an increasing need for a more systematic study on the basic issues involved in traditional Chinese medicine and a more active participation of researchers in the application area of nanoscale traditional Chinese drugs. In this...

A simple, accurate and sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed and validated for quantitation of bentysrepinine (Y101) in rat plasma. After the addition of diphenhydramine (internal standard, IS), plasma samples were pretreated by protein precipitation. Chromatographic separation was carried out on a...

The study aims to characterize the pharmacokinetic, tissue distribution, excretion, and antiviral activity properties of a novel pegylated recombinant human consensus interferon-α variant (PEG-IFN-SA) following a single subcutaneous administration to monkeys, rats and guinea pigs. Studies included: (1) pharmacokinetic properties of PEG-IFN-SA and c...

A highly selective and sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed for the quantification of scicinib, a novel thiosemicarbazone analogue and anticancer agent in rat plasma. Protein precipitation with saturated EDTA solution and methanol was selected for sample preparation, and brodimoprim was employed a...

Herbal medicines and their active ingredients are widely used worldwide, and they have become an important part of clinical medicine. The combined use of herbs and drugs has increased the possibility of pharmacokinetic and pharmacodynamic interactions. Clinical studies have demonstrated that the combined use of herbs and drugs can enhance or attenu...

In order to increase the dissolution rate and bioavailability, solid dispersions of evodiamine in PVP K(30) with different enriched samples of evodiamine to PVP K(30) ratios were prepared by solvent method. Our studies showed that the dissolution rate of evodiamine was significantly higher in the solid dispersion system in comparison with that in e...

Aim: In order to analyze the active compounds of extracts of Persimmon leaves, quantitative metabolomics approach was adopted to investigate the number of active compounds existing among different extracts as well as variation. and Methods: LC-MS method was established for quantitative determination of active compounds using mixture with standard c...

Ursolic acid is a hydroxy pentacyclic triterpene, which proved to have sedation, anti-inflammatory, antibacterial, antiulcer and anti-cancer activities. An ultra-performance liquid chromatography/tandem mass spectrometry (UPLC/MS/MS) method with high selectivity, sensitivity and throughput has been established and validated for quantitation of tota...

5-Fluorouracil (5-FU) has a broad spectrum of anti-tumor activity, widely applied to the treatment of cancers. However, it is necessary to determine the plasma concentration of 5-FU in clinical practice due to its narrow therapeutic index. Therefore, a simple, economic and sensitive high-performance liquid chromatography (HPLC) method was developed...

OBJECTIVE: To characterize the pharmacokinetics and excretion of icaritin in rats after oral and intravenous administration. METHODS: The concentrations of free icaritin and glucuronide-conjugates in rat plasma, urine and feces were determined. RESULTS: The ρmax and AUC0-∞ showed dose-dependent increase after oral doses of 20, 40 and 80 mg·kg -1, a...

Objective: To establish a specific and sensitive LC-MS/MS method for the determination of plasma aglycon of icariin in Beagle dogs. Methods: Aglycon of icariin and insternal standard tricin were extracted by ethyl acetate from plasma, then separated on a Zorbax C8 column. The mobile phase consisted of acetonitrile and 5% acetic acid (70:30). The pr...

We developed a rapid, simple and sensitive LC/MS/MS method for the simultaneous quantitation of tegafur (FT) and gimeracil (CDHP) in human plasma with a concentration range of 20-5000 and 2-500 ng/mL, respectively. Methanol was chosen as a precipitation agent for sample preparation. Chromatographic separation was performed on an inertsil ODS-3 C18...

The paper is to report the development of a high-performance liquid chromatographic/tandem mass spectrometry (HPLC-MS/MS) method for the determination of icaritin (ICT) in rat plasma. After precipitated with acetonitrile from the plasma, ICT was isolated chromatographically on a Dikma C18 column. The mobile phase consisted of acetonitrile-water-ace...

A rapid and sensitive LC-electrospray ionization-MS method was developed for determining vinorelbine in rat plasma. A 100 microL plasma sample was treated using a protein precipitation procedure and was chromatographed within 4 min using an Inertsil ODS-3 C(18 )(2.1 x 50 mm, 5 microm) column. The selected ion monitoring ions [M + H](+) were m/z 779...

A rapid, specific and sensitive ultra-performance liquid chromatography/tandem mass spectrometry (UPLC/MS/MS) method has been established for simultaneous quantitation of psoralen and isopsoralen in rat plasma. Plasma samples were pretreated by direct protein precipitation with acetonitrile. Chromatographic separations were performed on an ACQUITY...

A sensitive, rapid and specific liquid chromatography/tandem mass spectrometry (LC/MS/MS) assay has been established for the quantitation of catalpol in rat plasma. Plasma samples were treated by precipitating protein with methanol and were chromatographed by a Diamonsil C(18) column (150 mm x 4.6 mm I.D., 5 microm) with the mobile phase consisting...

Gender-related differences in drug pharmacokinetics have frequently been considered as potentially important determinants for the clinical effectiveness of drug therapy. Major molecular factors involved in drug disposition include drug-metabolising enzymes and drug transporters. Oxidative drug metabolism by cytochrome P450 (CYP) enzymes is a major...

Carbon tetrachloride (CCl(4)) is a well-known model compound for inducing chemical hepatic injury. This work characterizes the metabolism disorders of hepatotoxicity induced by CCl(4) in a Wistar rat model with a single dosage of 1 ml/kg. A seven-day long continuous collection of urine was performed in male rats in this experiment. Blood biochemist...

In the 21st century, nanoscience and nanotechnology obtains the world attention due to this revolutionary theory and technical features. Nanoscience and nanotechnology cover the theory and technology of physics, chemistry, medicine, material science, biomedical engineering and biology, therefore, they have no less contribution to science and techno...

A simple, sensitive and selective liquid chromatography-electrospray mass spectrometric (LC-ESI-MS) method was developed and validated for simultaneous determination of strychnine and brucine in rat plasma, using tacrine as the internal standard (IS). Sample preparation involved a liquid-liquid extraction of the analytes with n-hexane, dichlorometh...

An improved simple, rapid and accurate HPLC method for quantification of doxorubicin derived from micelle-encapsulated or liposome-encapsulated doxorubicin formulation in rat plasma was described. The mobile phase consisting of a mixture of methanol-water [containing 0.1% formic acid anhydrous and 0.1% ammonia solution (25%), pH 3.0], 60:40, was de...

The present article covers a simple approach to detect and subsequently identify in vivo metabolites of brodimoprim, using high performance liquid chromatography coupled to ion trap mass spectrometer(LC/ESI-MS), which is based on a data-dependent acquisition of isotope ions and result verified by full scan mass spectrum. The distinguished advantage...

Liquid chromatography-mass spectrometry was used to detect synthetical compounds illegally mixed into traditional Chinese medicine antidiabetic preparations. The organic extract of the traditional Chinese medicine antidiabetic capsule was analyzed through a C18 column with a mobile phase of methanol-formic acid (80.0:20.0:0.1). Two components illeg...

Alprostadil (PGE1) is endogenous substance that is able to dilate vessels, to inhibit platelet aggregation, therefore, potentially be active for the treatment of chronic arterial obstruction and microcirculation disturbance. However, because of its weak stability in biological matrixes, new delivery systems such as nanoparticle micelle needed to be...

Nano-assemblies of Phospholipids micelle can improve the penetration of doxorubicin to tumor cells, resulting in the enhancement of cytotoxicity of this anti-tumor agent. In order to investigate the targeting delivery of nano-particle doxorubicin in vivo with the reduced drug accumulation in the tissues, we studied the tissue distribution pharmacok...

The profiling of biomarkers in toxicology has been becoming increasingly important in assessing the health risks of exposure to potentially toxic drugs and chemicals. There are high expectations that the use of molecular profiling methods such as genomics, proteomics, and metabonomics will improve risk assessment and the identification of biomarker...

Mismatched double-stranded oligonucleotides (poly I: C12U), a kind of synthetic double-stranded ribonucleic acid (dsRNA), has a strong antiviral activity and great potency on malignant tumors. In the present study, we investigated the pharmacokinetic properties of mismatched double-stranded oligonucleotides (poly I: C12U) in rats. Wistar rats were...

Tissue distribution, urinary, fecal and biliary excretions of mismatched double-stranded oligonucleotides (poly I: C12U) were studied in Wistar rats. After a single intravenous administration of poly I: C12U at the dose of 10 mg/kg (10 μCi/100g125I-poly I: C12U), tissue samples of brain, heart, lung, liver, spleen, kidney, stomach, intestine, muscl...

Within the past few years, metabonomics, as a newpart of system biology, has gained great prominence besides genomics, transcriptomics and proteomics. Thus, it is necessary to detect in vivo metabolites thoroughly and exactly, which is traditionally considered as small endogenous compounds at trace levels, from complex biomatrice as the basic metho...

To develop and validate a liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for the determination of tamsulosin in dog plasma after oral administration of controlled-release tablet of tamsulosin hydrochloride, the samples and the internal standard, diphenhydramine, were extracted from dog plasma by n-hexane-dichloromethane (2 : 1),...

Nanotechnology is a newly fashionable field but in the world of drug development it is certainly not new. Nanotechnology has a vital role to play in realizing cost-effective diagnostic, therapeutic and prevent tools. The applications of nanotechnology for treatment, diagnosis, monitoring and control of biological systems have recently been referred...

Liquid chromatography/electrospray ionization tandem mass spectrometry (LC/MS(n)) was used to identify trace levels of in vivo metabolites after the administration of isovalertatin M23 or isovalertatin D23 to rats. The biosamples of urine, feces, and ileum incubation were pre-treated by solid-phase extraction (SPE), and then chromatographed with a...

Four new aminooligosaccharides, isovalertatins M33 1, D13 2, D33 3, and D43 4, were isolated from the culture filtrate of Streptomyces luteogriseus. Their structures were established by chemical and spectroscopic evidences including ESI multistage mass spectrometry and 2-dimensional NMR techniques, and were found in full consistencies with the prev...

Preparation of glucuronide conjugates of etofesalamide[N-(4-ethoxyphenyl)-2-hydroxyl-benzamide], a novel drug for acne therapy, in rabbit was discribed. Urine samples from 0 to 12 h were collected after single oral administration of 400 mg etofesalamide to two rabbits. The samples were lyophilized and extracted with methanol, and then etofesalamide...

Investigation of the aerial part of Stephania tetrandra led to the isolation of two biflavonoids, stephaflavone A and stephaflavone B, with a 3-6" linkage pattern, together with beta-sitosterol. Their structures were established on the basis of their spectroscopic data and their physicochemical properties.

Two novel aminooligosaccharides, butytatins M03 and M13 were isolated and purified from the culture filtrate of Streptomyces luteogriseus. Analysis by liquid chromatography coupled to electrospray ionization mass spectrometry indicated their resemblance to isovalertatin, with a four-carbon acyl group. Their structures were established by NMR as ami...

A rapid and novel procedure using the liquid chromatography coupled to an electrospray ionization ion trap mass spectrometry technique was applied for the profiling of isovalertatin-family aminooligosaccharides in the extract from the culture filtrate of Streptomyces luteogriseus. The aminooligosaccharides were separated on a C-8 reversed-phase col...

Three aminooligosaccharides, isovalertatins M03 (1), M13 (2), and M23 (3) were isolated and purified from the culture filtrate of Streptomyces luteogriseus. Their physicochemical properties, liquid chromatographic behavior, and spectroscopic data were in full accordance with the reported compounds [Xu, Q.; Wang, Q.; Lu, D. CN Patent 1100756, 1995;...

Two aminooligosaccharides, isovalertatins D03 (1) and D23 (2), were isolated from the culture filtrate of Streptomyces luteogriseus. Their structures were reinvestigated and revised by spectroscopic evidences including ESI multistage mass spcctrometry and 2-dimensional NMR techniques.

Chromatographic separation of the EtOH extract from the aerial parts of Stephania tetrandra resulted in the isolation of a novel 4,5-dioxoaporphine alkaloid, stephadione {1}, together with six known alkaloids: corydione, oxonantenine, cassameridine, nantenine, cassythicine, and tetrandrine. The structure of stephadione was determined to be 6a,7-di-...

Doxorubicin is an anthraquinone anticancer agent, which has been used for the treatment of human malignancies. Unfortunately, its long-term clinical use is limited by unwanted side effects including cumulative dose-relatd cardiotoxicity, myelosuppression, and the development of drug resistance. In efforts to improve antitumor efficacy and reduce to...

Aildenafil, 1-{[3-(6, 7-dihydro-1-methyl-7-oxo-3-propyl-1Hpyrazolo [4,3-d] primidin-5-yl)-4-ethoxyphenyl] sulfonyl}-cis-3, 5-dimethylpiperazine, as a pyrrolopyrimidinone analogue of sildenafil and verdenafil, is a potent inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type V by degrading of cGMP in the corpus cavernosu...

Aildenafil, 1-{[3-(6, 7-dihydro-1-methyl-7-oxo-3-propyl-1Hpyrazolo [4,3-d] primidin-5-yl)-4-ethoxyphenyl] sulfonyl}-cis-3, 5-dimethylpiperazine, as a pyrrolopyrimidinone analogue of sildenafil and verdenafil, is a potent inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type V by degrading of cGMP in the corpus cavernosu...

Liver was one of the main metabolic and excretory organs for drug, so it was meaningful to research the mechanism of drug absorption and excretion in liver. Liver transporter was the functional protein expressed on the surface of hepatocyte membrane. It was one of the most important approaches for drug to pass in and out of hepatocytes. Host cell s...

The content of activated pharmaceutical ingredients can be absorbed in intestine of human, it is a major factor, deciding whether the medicine can play biological activity or not. Nowadays, Caco-2 and MDCK cell models are used widely to study drug intestinal absorption process in vitro experiments [1-2]. Caco-2 cell line derived from human colon ad...

Pharmacokinetics of Recombinant Human Thymosin 1 (rhT1) in Rats CaiYongming1,2, Shen Wenjin2, Li Chunyu2, Zhang Zongpeng1,2, Si Duanyun1, Liu Changxiao1,2 (1 State Key Laboratory of Drug Delivery Technology and Pharmacokinetics, Tianjin Institute of Pharmaceutical Research, Tianjin 300193, China£2Tianjin Centre for Drug Safety Evaluation and Rese...

Strychnine is an alkaloid which is isolated from the seeds of Strychnos nux-vomica. It has been used as a medicine or a poison since early 1800's. In recent decades, the usage of strychnine has been limited by its narrow therapeutic window and fatal toxicity. However, since strychnine has strong pharmacological activities of stimulating spinal nerv...