Latest ArticlesThis study was designed to investigate triterpenoids from the roots of Rosa laevigata Michx. The silica gel column chromatography was used to separate the chemical constituents from the roots of Rosa laevigata Michx. HPLC was used to analyze its purity and chemical constitution. Spectroscopy methods were used to determine their structures. Five constituents were isolated and identified as19α-OH-3β-E-feruloyl corosolic acid (1), 23-hydroxy-tormentic acid (2), 2α, 3β, 19α, 23-tetrahydroxy-12-en-28-oleanolic acid (3), 2α, 3α, 20β-trihydroxyurs-13 (18)-en-28-oic-acid (4), 2α, 3β, 20β-trihydroxyurs-13 (18)-en-28-oic-acid (5). Compound 1 was assigned as a new compound, compounds 4, 5 were obtained from the genus Rosa for the first time.
Human chorionic gonadotrophin (hCG), a glycohormone widely used in treatment of infertility, is a heterodimer composed of an alpha-and a beta-subunit. The heterodimer could be dissociated during production and storage with an impact on its bioactivity. A CE-SDS method for quantitative analysis of hCG subunit dissociation was established in this study by optimization of a variety of method conditions including sample preparation buffer compositions, incubation temperature, separation voltage, and capillary temperature. This method was validated for good sensitivity, linearity, precision, and accuracy for both α-and β-subunit. CE-SDS also showed much better precision and accuracy than SDS-PAGE. The method was successfully used in both recombinant hCG (r-hCG) produced by cell culture and hCG (u-hCG) derived from urine. The CE-SDS method was used in the study of hCG development and stability. Therefore, it is an useful tool for the quality control of hCG.
The biological potency assay and chemical fingerprint chromatogram were applied to quality evaluation of rhubarb. Using the biological potency as indicators, we evaluated the differences in quality of multiple batches of rhubarbs and related products. Using the platelet aggregation analyzer, we determined platelet aggregation rate in the different rhubarbs preparations, and calculated the biological potency based on the simplified probit principle. UPLC was adopted to establish the fingerprint spectra for rhubarbs. The spectral efficiency correlation analysis between chromatograms and biological potencies were conducted using the double variables of SPSS 22.0 software. We used three chemical composition to verify the potency. The biological potency results suggest that Rheum palmatum has a more potent activity than Rheum tanguticum, and wine-treated rhubarb had a higher potentcy than charred. We identified 10 elements in the Fingerprint Spectrum. The relevant elements including rhein-8-O-β-D-glucoside, emodin-8-O-β-D-glucoside and rhein have the strongest activity in the inhibition of platelet aggregation. In conclusion, this study provides a analytical method for rhubarb biological potency based on determination of the maximum antagonism rate model. The rhein may be the effective substance. It may serve as a reference in the quality control of wine processed rhubarb products.
Donafenib is the deuterium derivative of sorafenib, and is an anti-tumor drug in clinical trials. An accurate and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the simultaneous determination of donafenib and its N-oxide metabolite in human plasma. The analytes and internal standards (sorafenib and sorafenib N-oxide) were extracted from plasma by protein precipitation with acetonitrile, and separated on a Gemini C18 (50 mm×2.0 mm, 5 μm) column using a gradient elution procedure. The mobile phase consisted of acetonitrile and 5 mmol·L-1 ammonium acetate (0.2% formic acid) at a flow rate of 0.7 mL·min-1. The total run time was 5.0 min. Positive electrospray ionization was performed using multiple reaction monitoring (MRM) with transitions of m/z 468.2→273.2 for donafenib and m/z 465.2→270.2 for its internal standard sorafenib, m/z 484.2→289.2 for donafenib N-oxide and m/z 481.2→286.2 for its internal standard sorafenib N-oxide. The standard curves were linear in the range of 5.00-5 000 ng·mL-1 for donafenib, and 1.00-1 000 ng·mL-1 for donafenib N-oxide. The method was validated and successfully applied to the pharmacokinetics study of donafenib tosylate tablets in volunteers.
To study the metabolic products of main compounds of Chuankezhi injection in rat, 12 Sprague Dawley rats were classed into 2 groups, a blank control group and an intermuscular administration group, respectively. Rat feces and urine samples were collected from 0-24 h and 24-48 h after administration. All the samples were ultrasonically treated with methanol and then analyzed using LC-LTQ Orbitrap MSn. By comparison with the total ion chromatogram of samples from the blank control group, the metabolites in the samples of drug-treated group were screened. These metabolites were further analyzed by multistage product ion scanning and comparison of retention time with reference substances. As a result, a total of 12 flavonoid metabolites were tentatively identified from the rat feces and no metabolite was discovered in the rat urine. Epimedin C and icariin were detected in the rat blood samples after 30 min of administration, but their metabolites and other original flavones were not detected. Furthermore, no original flavones and their metabolites were detected in rat blood samples after 2 and 4 h of administration. The potential metabolism paths were further characterized and the principal in vivo transformation of flavones from Chuankezhi injection were deglycosylation, dehydration, methylation, oxidation and isomerization in rats.
A new method was developed for the chromatographic fingerprint analysis of Toosendan Fructus by HPLC coupled with the charged aerosol detector (CAD) in the present study. Samples were well separated on an Agilent ZOBAX SB C18 column (4.6 mm×250 mm, 5 μm) by gradient elution using acetonitrile and water containing 0.1% formic acid (v/v) at the flow rate of 1.0 mL·min-1. The column temperature was 30℃ and the injection volume was 5 μL. The nitrogen inlet pressure of the charged aerosol detector (CAD) was 35 psi, and the nebulizer chamber temperature was 35℃. In addition, the method of the chromatographic fingerprints combined with multivariate statistical analysis was effective and reasonable lead to an accurate classification of 20 batches of samples from different locations. The results showed that 28 common peaks were observed in the fingerprint and the samples were classified into three clusters. The established method was well validated, and showed high precision, good repeatability, and satisfactory stability. It may serve in the quality control and evaluation of Toosendan Fructus.
Our research was designed for on-line detection of multi-index in the concentration process of Ganmaoling granules by integration of near infrared spectroscopy and automatic control system. First, on-line detection system was set up in the concentration tank for Ganmaoling granules production. Spectra were scanned and values of chlorogenic acid, linarin, solid content and relative density were measured. Models of partial least squares regression were built and imported into near infrared workstation. By connecting the control system, real-time multi-index values were determined automatically in the concentration process. Results showed that correlation coefficients of chlorogenic acid, linarin, solid content and relative density models were 0.963, 0.989, 0.993 and 0.918, respectively. Relative standard errors of prediction were 3.71%, 4.28%, 4.17% and 0.24%, respectively, indicating a good performance and high accuracy of the models. Real-time data collection during the whole process was measured by the near infrared detecting system in the control system. In conclusion, the near infrared detection system is able to perform real-time automatic determination of multi-index in the concentration process of Ganmaoling granules with significant advantages.
Inhibition of apoptosis induced by oxidative stress is an effective way to reduce myocardial injury. In this study, we used H2O2-stimulated rat cardiac myoblast cell line (H9c2) as an oxidative damage model. Curcumin (Cur) was chosen as a model drug and mesoporous silica nanoparticles (MSNs) were chosen as the carrier to construct a Cur-loaded delivery system (Cur@MSNs) and to examine its protective effects against oxidative damage. The MSNs guaranteed efficient loading and controlled release of Cur. Besides, the hydrophilicsilanol groups on the surface of MSNs promoted the Cur solubility in water and increased its cellular uptake amount, which improved the bioavailability of Cur. The results suggest that the Cur@MSNs was pharmacologically active in the reduction of the oxidative damage of H9c2 cells. It was verified that a great decrease of reactive oxygen species was inducted by Cur@MSNs, which led to the protective effects against oxidative damage.
In this study, the endocytosis pathway of heparosan and its intracellular distribution were investigated in MCF-7 tumor cells and COS7 normal cells. The endocytosis inhibition and cellular probe location experiments showed that MCF-7 tumor cells took heparosan more efficiently and selectively than COS7 cells. The cellular uptake of heparosan was energy-dependent in both MCF-7 tumor cells and COS7 normal cells. Moreover, the major endocytosis pathway of heparosan into MCF-7 tumor cells was caveolin-mediated endocytosis and macropinocytosis. The internalized heparosan was mainly located in lysosomes of the cells.
In this study, water-dispersible magnetic iron oxide (Fe3O4) nanoparticles were synthesized with solvothermal method. The nanoparticles were characterized with a transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). The in vitro magnetic resonance response and photothermal conversion characteristics of the nanoparticles were evaluated. In addition, the cellular uptake, cytotoxicity and biodistribution were studied. Finally, magnetic resonance/photothermal dual-modal imaging effect of the as-synthesized Fe3O4 nanoparticles was investigated in the tumor-bearing mice. The results showed that the obtained magnetic nanoparticles were uniform with a mean diameter of about 125 nm. Moreover, the superparamagnetic Fe3O4 nanoparticles showed remarkable magnetic resonance response and photothermal conversion properties. The results of cellular experiments showed that the cell viability was nearly 85% even the concentration of the nanoparticles was up to 1 000 μg·mL-1, an indicator of good biocompatibility. In addition, the nanoparticles could be taken up by the tumor cells and then located in the cytoplasm. After intravenous injection, the nanoparticles were tended to enrich in the tumor over time, which is helpful in achieving dual-modal magnetic resonance/photothermal imaging. In sum, the obtained Fe3O4 nanoparticles showed great potential to be applied for multi-modal bio-imaging which may play an important role in the diagnosis of tumors.