Pu Jia

Effects of ionic liquid and nanogold particles on high-performance liquid chromatography-electrochemical detection and their application in highly efficient separation and sensitive analysis of five phenolic acids in Xuebijing injection

A novel high performance liquid chromatography-electrochemical detector (HPLC-ECD) analytical system was developed in this study by integratedly utilizing ionic liquid (IL) of 1-butyl-3-methylimidazolium bromide and an additive of gold nanoparticles. The resulted pilot study was first performed to assess the effects of 1-butyl-3-methylimidazolium bromide and gold nanoparticles on the chromatographic characteristics of five phenolic acids in Xuebijing injection, including danshensu (DSS), protocatechuic acid (PA), protocatechuic aldehyde (PAH), hydroxy safflower yellow A (HSYA) and ferulic acid (FA). It was notable to observe that retainability of the phenolic acids were markly lowered by IL addition. Compared with the cases without IL addition, the retention times of DSS, PA, PAH, HSYA and FA have decreased 2.851, 1.532, 1.53, 0.818 and 0.552 min, respectively when 0.6% IL in the mobile phase. In addition, the corresponding theoretical plate numbers and peak areas for these compounds were significantly increased. Area response for DSS, PA, PAH, HSYA and FA were enhanced by 772%, 628%, 584%, 703% and 600%, respectively. It was observed that nano-gold catalysis power enabled peak areas of DSS, PAH, FA and PA to enhance 5.7, 6.2, 8.5 and 66.5 times relative to the case with addition of IL. Altogether, the optimized HPLC-ECD system was successfully applied to the pharmacokinetics study of Xuebijing injection with underlying applicability to in vivo and in vitro analysis of a variety of natural product from Chinese medicine plants, TCM formulae and associated patent TCM preparation.

Reversing P-glycoprotein-mediated multidrug resistance in vitro by α-asarone and β-asarone, bioactive cis–trans isomers from Acorus tatarinowii

P-Glycoprotein (P-gp), an ATP-binding cassette transporter, plays an important role in multidrug resistance (MDR). α-Asarone and β-asarone, bioactive cis–trans isomers found in Acorus tatarinowii Schott, were tested for their potential ability to modulate the expression and function of P-gp in Caco-2 cells. MTT assays revealed that both α-asarone and β-asarone significantly enhanced the vincristine-induced cytotoxicity to cells. β-Asarone was the most potent. Flow cytometry showed that α- and β-asarone increased Rhodamine 123 (Rh123) uptake and inhibited Rh123 efflux in Caco-2 cells in a concentration-dependent manner. Furthermore, P-gp expression and P-gp mRNA in cells were decreased by exposure to α- and β-asarone. In addition, β-asarone increased the inhibition of P-gp activity in cells more than α-asarone. Thus, α- and β-asarone effectively reversed MDR by inhibiting P-gp function and expression.

Simultaneous Determination of Volatile Constituents from Acorus tatarinowii Schott in Rat Plasma by Gas Chromatography-Mass Spectrometry with Selective Ion Monitoring and Application in Pharmacokinetic Study

A sensitive and specific gas chromatographic-mass spectrometry with selected ion monitoring (GC-MS/SIM) method has been developed for simultaneous identification and quantification of α-asarone, β-asarone, and methyl eugenol of Acorus tatarinowii Schott in rat plasma. Chromatographic separation was performed on a Restek Rxi-5MS capillary column (30 m × 0.32 mm × 0.25 μm), using 1-naphthol as internal standard (IS). MS detection of these compounds and IS was performed at m/z 178, 208, 208, and 144. Intra- and interday precisions of all compounds of interest were less than 10%. The recoveries are situated in the range of 92.4–105.2%. Pharmacokinetics of methyl eugenol confirmed to be one-compartment open model, α-asarone and β-asarone was two-compartment open model, respectively. The method will probably be an alternative to simultaneous determination and pharmacokinetic study of volatile ingredients in Acorus tatarinowii Schott.

A simple and novel strategy for the simultaneous determination of dopamine, acetamidophenol and tryptophan based on poly(new coccine) film modified carbon paste electrode

A polymerized film of new coccine was deposited on a carbon paste electrode (CPE) by an electropolymerization technique. Electrochemical characterization of the modified electrode was investigated by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The poly(new coccine) modified CPE exhibited excellent electrocatalytic activity towards the oxidation of dopamine (DA), acetaminophenol (AP) and tryptophan (Trp) simultaneously. Well defined and separated oxidation peaks were observed by CV. Linear calibration plots for the oxidation of DA, AP and Trp were obtained in the range of 0.7–200 μM for DA, 1.5–120 μM for AP, and 0.6–50 μM for Trp. Detection limits of DA, AP and Trp were found to be 0.2, 0.3 and 0.2 μM, respectively. With good selectivity and sensitivity, the present method has been successfully applied to the determination of DA, AP and Trp in pharmaceutical samples.

Metabolomic analysis provides novel chemotaxonomic characteristics for phenotypic cultivars of tree peony

Metabolomic analysis is an important molecular phenotyping method for understanding plant ecotypic variations. Here, we systematically characterized the metabolomic variations associated with five Chinese cultivars of tree peony (Paeonia suffruticosa Andrews) using high performance liquid chromatography-mass spectrometry (HPLC-MS) and multivariate data analysis. Our results indicated that the metabolite profile of the root bark in tree peony was largely dominated by 5 primary metabolites and 41 secondary ones including 7 phenolics, 7 flavonoids, 16 monoterpene glycosides and 11 acetophenones. The distribution of these secondary metabolites varied in the different tree peony cultivars. Some secondary metabolites, such as galloyl glucoses, procyanidins, mudanpiosides and acetophenones, will become the novel and potential chemotaxonomic markers to differentiate tree peony cultivars when the conventional classification methods are not practicable. These results demonstrated that HPLC-MS based metabolomics was an effective tool for the classification of phenotypic cultivars and provided novel and potential chemotaxonomic characteristics of tree peony.

Liquid Chromatography/Quadrupole Time-of-Flight Mass Spectrometry for Identification of In Vitro and In Vivo Metabolites of Bornyl Gallate in Rats

Bornyl gallate (BG) is a potential drug candidate synthesized by the reaction of two natural products, gallic acid and borneol. Previous studies have strongly suggested that BG is worthy of further investigation due to antioxidant, antiatherosclerosis activities, and obvious activity of stimulating intersegmental vessel growth in zebrafish. This work was designed to elucidate the metabolic profile of BG through analyzing its metabolites in vitro and in vivo by a chromatographic separation coupled with a mass spectrometry. The metabolites of BG were characterized from the rat liver microsome incubation solution, as well as rat urine and plasma after oral administration. Chromatographic separation was performed on an Agilent TC-C18 column (250 mm × 4.6 mm, 5 μm) with gradient elution using methanol and water containing 0.2% (V : V) formic acid as the mobile phase. Metabolites identification involved analyzing the retention behaviors, changes of molecular weights and MS/MS fragment patterns of BG and the metabolites. Five compounds were identified as isomers of hydroxylated BG metabolites in vitro. The major metabolites of BG in rat urine and plasma proved to be BG-O-glucuronide and O-methyl BG-O-glucuronide. The proposed method confirmed to be a reliable and sensitive alternative for characterizing metabolic pathways of BG.

Cold water forced swimming stress induced metabolic alterations in rats

Forced swimming in cold water causes physiological and psychological stress that leads to altered biochemical homeostasis and neurobehavioral responses. In this study, plasma and urinary metabolites in Sprague-Dawley (SD) rats subjected to cold water forced swimming stress (CWFSS) were characterized using NMR in conjunction with multivariate data analysis. Metabolic analysis demonstrated that decreased levels of lipoprotein and increased levels of O-acetyl glycoprotein, glucose, lactate, pyruvate, creatine, citrate, succinate and amino acids including phenylalanine, tyrosine, glutamate, valine, isoleucine, alanine and lysine in plasma were observed in response to CWFSS. Moreover, the biochemical response to CWFSS as determined from NMR analysis of urine was characterized by an elevation of gut microbiota-related metabolites including phenylacetylglycine, 4-cresol glucuronide and indoxyl sulfate. These results suggest that CWFSS-induced metabolic perturbations were involved in the disruption of amino acid and energy metabolism as well as the alteration of gut microbiota function. This study will enhance the current knowledge of stress-induced diseases and aid in the early diagnosis of metabolic disorders in humans.

(E)-Isopropyl 3-(3,4-dihy-droxy-phen-yl)acrylate.

In the title compound, C12H14O4, a derivative of caffeic acid [(E)-3-(3,4-dihydroxyphenyl)-2-propenoic acid], an intramolecular O—H⋯O hydrogen bond forms an S(5) ring. In the crystal, intermolecular O—H⋯O hydrogen bonds link molecules into chains propagating in [110].