Yunpeng Qi

Physicochemical characterization and pharmacokinetics evaluation of β-caryophyllene/β-cyclodextrin inclusion complex.

β-Caryophyllene (BCP), a natural sesquiterpene existing in the essential oil of many plants, has exhibited a wide range of biological activities. However, its volatility and poor water-solubility limit its application in pharmaceutical field. β-Cyclodextrin (β-CD) has intrinsic ability to form specific inclusion complexes with different drugs to enhance their stability, solubility and bioavailability. The aim of this study is to investigate and compare the oral bioavailability and the pharmacokinetics of free BCP and BCP/β-CD inclusion complex after a single oral dose of 50mg/kg on rats. A simple, rapid, and sensitive gas chromatography-mass spectrometry method in selected ion monitoring (GC-MS/SIM) mode was developed on determination of BCP in rat plasma. The in vivo data showed that BCP/β-CD inclusion complex displayed earlier Tmax, higher Cmax and the AUC0-12h was approximately 2.6 times increase than those of free BCP. These results demonstrated that BCP/β-CD inclusion complex has significantly increased the oral bioavailability of the drug in rats than free BCP.

High-throughput determination of fudosteine in human plasma by liquid chromatography–tandem mass spectrometry, following protein precipitation in the 96-well plate format

A 96-well protein precipitation, liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed and fully validated for the determination of fudosteine in human plasma. After protein precipitation of the plasma samples (50 microL) by the methanol (150 microL) containing the internal standard (IS), erdosteine, the 96-well plate was vortexed for 5 min and centrifuged for 15 min. The 100 microL supernatant and 100 microL mobile phase were added to another plate and mixed and then the mixture was directly injected into the LC-MS/MS system in the negative ionization mode. The separation was performed on a XB-CN column for 3.0 min per sample using an eluent of methanol-water (60:40, v/v) containing 0.005% formic acid. Multiple reaction monitoring (MRM) using the precursor-product ion transitions m/z 178-->91 and m/z 284-->91 was performed to quantify fudosteine and erdosteine, respectively. The method was sensitive with a lower limit of quantification (LLOQ) of 0.02 microg mL(-1), with good linearity (r>0.999) over the linear range of 0.02-10 microg mL(-1). The within- and between-run precision was less than 5.5% and accuracy ranged from 94.2 to 106.7% for quality control (QC) samples at three concentrations of 0.05, 1 and 8 microg mL(-1). The method was employed in the clinical pharmacokinetic study of fudosteine formulation product after oral administration to healthy volunteers.

A plasma metabonomic investigation into the intervention of volatile oil of Magnolia biondii Pamp on rat model of acute inflammation

ETHNOPHARMACOLOGICAL RELEVANCE The dried flower buds of Magnolia biondii Pamp (Magnoliaceae) possesses significant anti-inflammatory activities. AIM OF THE STUDY Volatile oil in Magnolia biondii Pamp (VOMbP) is considered to be important pharmacologically active individuals against acute inflammation, but its exact anti-inflammatory mechanism remains elusive. In this study, we aimed to investigate the intervention of VOMbP on rats with acute inflammation and explore the possible anti-inflammatory mechanisms of VOMbP with metabonomic strategy. MATERIALS AND METHODS Acute inflammation was induced by subcutaneously injection of carrageenan in the rats. Plasma was analyzed using gas chromatography-mass spectrometry (GC-MS), based on which the principal component analysis (PCA) and partial least squares-discriminate analysis (PLS-DA) models were established for metabonomic analysis. RESULTS It was revealed that the pretreatment of VOMbP in acute inflammatory rats induces a substantial and characteristic change in their metabolic profiles. Some significantly changed metabolites, including hexadecanoic acid, linoleic acid, oleic acid, stearic acid, and cholesterol, were found to be reasonable in explaining the anti-inflammatory mechanism of VOMbP. CONCLUSIONS In all, it is likely that VOMbP intervenes the metabolic process of inflammatory rats by affecting the fatty acid and cholesterol metabolism. Our work also indicated that the metabonomics method is a promising tool for performing intervention and mechanism research of traditional Chinese medicines.

Simultaneous chemical fingerprint and quantitative analysis of Rhizoma Smilacis Glabrae by accelerated solvent extraction and high-performance liquid chromatography with tandem mass spectrometry.

Rhizoma Smilacis Glabrae (RSG) is a well-known herbal medicine with the homology of medicine and food. In this study, simultaneous chemical fingerprint and quantitative analysis of the bioactive flavonoid components of RSG were developed using accelerated solvent extraction and high-performance liquid chromatography coupled with ion trap tandem mass spectrometry. The operational parameters of accelerated solvent extraction including extraction solvent, extraction temperature, static extraction time, solid-to-liquid ratio, and extraction cycles were optimized. Hierarchical cluster analysis, similarity analysis, and principal component analysis were performed to evaluate the similarity and variation of the samples collected from several provinces in China. Subsequently, high-performance liquid chromatography fingerprints were established for the discrimination of 16 batches of RSG samples, and the major six flavonoids, namely, toxifolin, neoastilbin, astilbin, neoisoastilbin, isoastilbin, and engeletin were then quantitatively determined. The calibration curves for all the six analytes showed good linearity (r(2) > 0.999), and the limits of detection and quantification were less than 0.10 and 0.27 μg·mL(-1) , respectively. Therefore, the proposed extraction and determination methods were proved to be robust and reliable for the quality control of RSG.

Isolation and purification of diastereoisomeric flavonolignans from silymarin by binary‐column recycling preparative high‐performance liquid chromatography

Silymarin extracted from Silybum marianum (L.) Gaertn consists of a large number of flavonolignans, of which diastereoisomeric flavonolignans including silybin A and silybin B, and isosilybin A and isosilybin B are the main bioactive components, whose preparation from the crude extracts is still a difficult task. In this work, binary-column recycling preparative high-performance liquid chromatography systems without sample loop trapping, where two columns were switched alternately via one or two six-port switching valves, were established and successfully applied to the isolation and purification of the four diastereoisomeric flavonolignans from silymarin. The proposed system showed significant advantages over conventional preparative high-performance liquid chromatography with a single column in increasing efficiency and reducing the cost. To obtain the same amounts of products, the proposed system spends only one tenth of the time that the conventional system spends, and needs only one eleventh of the solvent that the conventional system consumes. Using the proposed system, the four diastereoisomers were successfully isolated from silymarin with purities over 98%.

Metabolomics Study of Resina Draconis on Myocardial Ischemia Rats Using Ultraperformance Liquid Chromatography/Quadrupole Time-of-Flight Mass Spectrometry Combined with Pattern Recognition Methods and Metabolic Pathway Analysis

Resina draconis (bright red resin isolated from Dracaena cochinchinensis, RD) has been clinically used for treatment of myocardial ischemia (MI) for many years. However, the mechanisms of its pharmacological action on MI are still poorly understood. This study aimed to characterize the plasma metabolic profiles of MI and investigate the mechanisms of RD on MI using ultraperformance liquid chromatography/quadrupole time-of-flight mass spectrometry-based metabolomics combined with pattern recognition methods and metabolic pathway analysis. Twenty metabolite markers characterizing metabolic profile of MI were revealed, which were mainly involved in aminoacyl-tRNA biosynthesis, phenylalanine, tyrosine, and tryptophan biosynthesis, vascular smooth muscle contraction, sphingolipid metabolism, and so forth. After RD treatment, however, levels of seven MI metabolite markers, including phytosphingosine, sphinganine, acetylcarnitine, cGMP, cAMP, L-tyrosine, and L-valine, were turned over, indicating that RD is likely to alleviate MI through regulating the disturbed vascular smooth muscle contraction, sphingolipid metabolism, phenylalanine metabolism, and BCAA metabolism. To our best knowledge, this is the first comprehensive study to investigate the mechanisms of RD for treating MI, from a metabolomics point of view. Our findings are very valuable to gain a better understanding of MI metabolic profiles and provide novel insights for exploring the mechanisms of RD on MI.

Global Metabolic Profiling Using Ultra-Performance Liquid Chromatography/Quadrupole Time-of-Flight Mass Spectrometry

Currently, liquid chromatography-mass spectrometry (LC-MS) is one of the most important analytical technologies for detecting hundreds of metabolites in the field of metabolomics. A recent advance in LC that has impacted metabolomics is the development of UPLC (ultra-performance liquid chromatography). In this chapter, we describe the analytical methodologies for the global metabolic profiling of serum, urine, and tissue samples using UPLC-Q-TOF (quadrupole-time-of-flight)-MS. Aqueous metabolites are extracted after adding methanol/acetonitrile/acetone and then analyzed by UPLC-MS under positive and/or negative ionization mode. With the aid of multivariate statistical analysis, separation between various groups can be observed in the score plots, and biomarkers are screened in the loading/weight/VIP (variable importance in the projection) scatterplots. Furthermore, putative markers can be identified through comparison with the authentic standards based on tandem mass spectrometry (MS/MS) fragmentation pattern and LC retention. We expect that our protocol, with modifications if necessary, can be useful in many metabolomics studies and a wide range of research areas related to small molecules and LC-MS.

Metabonomic Investigation on Plasma Samples of Liver Transplanted Rats

In recent years, more sensitive and less invasive methods for detecting organ transplantation rejection have been receiving increasing interest. Metabonomics is a recent development in the transplantation field. In this paper, a metabonomic investigation on plasma samples of liver transplanted rats was presented. Samples from control, syngeneic, and allogeneic transplanted groups were analyzed using GC-MS after derivatization. Thirty-six metabolites in the acquired GC-MS data, including amino acids, organic acids, carbohydrates, and some other metabolites were identified and matched by NIST spectral library. The scores plot of principal component analysis (PCA) showed that the three groups were unambiguously apart from each other; the syngeneic liver transplanted group and the control group were adjacent, indicating a high similarity between the two groups; the allogeneic liver transplanted group, however, was apparently separate from the other two groups, demonstrating the significant differences of metabonomic profiles among the groups with or without immunologic reaction. Among the identified thirty-six metabolites, galactose, D-glucose, L-deoxyglucose, gulose, cholesterol, urea, and L-aspartic acid were found to be the significantly changed metabolites according to PCA loadings plot. In the allogeneic liver transplanted group, levels of cholesterol, urea, and L-aspartic acid increased but galactose, D-glucose, L-deoxyglucose, and gulose levels declined compared to those in the control and the syngeneic liver transplanted groups.