Simultaneous determination of synephrine, arecoline, and norisoboldine in Chinese patent medicine Si-Mo-Tang oral liquid preparation by strong cation exchange high performance liquid chromatography.

Context: Chinese patent medicine Si-Mo-Tang oral liquid preparation (SMT) is composed of Aucklandia luppa Decne (Compositae), Citrus aurantium Linn (Rutaceae), Lindera aggregata (Sims) Kosterm (Lauraceae), and Areca catechu Linn (Arecaceae). Studies of SMT have been impeded due to the lack of quality control methods.

Objective: This study aimed to simultaneously determine three alkaloids including synephrine, arecoline, and norisoboldine in SMT for the first time.

Screening and identification of radical scavengers from Neo-Taraxacum siphonanthum by online rapid screening method and nuclear magnetic resonance experiments.

An online rapid screening method, the high-performance liquid chromatography (HPLC)-diode array detector (DAD)-radical scavenging detection (RSD)-electrospray ionization (ESI)-mass spectroscopy (MS)/MS system, was developed for the screening and identification of radical scavengers from Neo-Taraxacum siphonanthum, a new species found in China in 1989. For further characterization, the target compounds were isolated by silica column chromatography, preparative high-performance liquid chromatography (HPLC), HSCCC, and Sephadex LH-20 column chromatography and elucidated on the basis of ultraviolet (UV), ESI-MS/MS, and nuclear magnetic resonance (NMR) spectroscopy, as well as the chemical analysis. Eighteen antioxidative polyphenols (5 caffeic acid derivatives and 13 flavonoid derivatives) were characterized from Neo-T.

Optimization of microwave-assisted extraction of protopine and allocryptopine from stems of Macleaya cordata (Willd) R. Br. using response surface methodology.

The purpose of the research was to investigate the multiple response optimizations for the extraction of protopine and allocryptopine from the stems of Macleaya cordata (Willd) R. Br. by using microwave-assisted extraction (MAE).

Preparation and characterization of 5'-phosphodiesterase from barley malt rootlets.

Two 5'- phosphodiesterases (5'-PDE-a and 5'-PDE-b) were isolated from barley malt rootlets, and further purified by gel filtration on Sephadex G-25 and Sephadex G-75. 5'-PDE-a had a pH optimum of 5.0, temperature optimum of 70 degrees C, and specific activity of 0.

All-trans retinoic acid inhibits cobalt chloride-induced apoptosis in PC12 cells: role of the dimethylarginine dimethylaminohydrolase/asymmetric dimethylarginine pathway.

Previous studies have shown that the endogenous nitric oxide synthase inhibitor asymmetric dimethylarginine (ADMA) and its specific hydrolase dimethylarginine dimethylaminohydrolase (DDAH) are involved in the regulation of apoptosis in different cell types. In the present study, we investigated the role of the DDAH/ADMA pathway in cobalt chloride (CoCl(2))-induced apoptosis and the antiapoptotic effect of all-trans retinoic acid (atRA) in undifferentiated pheochromocytoma (PC12) cells. Treatment of CoCl(2) (125 microM) for 48 hr significantly induced the apoptosis of PC12 cells, concomitantly with increased intracellular reactive oxygen species (ROS) production and caspase-3 activity.

[Progress in the research of carbon nanotubes as drug carriers].

Research and development of new drug carriers are crucial to the research of drugs. Due to their unique hollow structure and nano-diameter, carbon nanotubes (CNTs) can be used as drug carriers. Functionalization of CNTs with peptides, proteins, nucleic acids or even drug molecules, the so obtained functionalized CNTs can be used as carriers to deliver bioactive molecules into cells without causing any toxicity.

Bis[μ-2-(2-naphth-oxy)acetato]bis-{aqua[2-(2-naphth-oxy)acetato]zinc(II)}.

The title binuclear Zn(II) compound, [Zn(2)(C(12)H(9)O(3))(4)(H(2)O)(2)], is centrosymmetric. Each Zn atom is coordinated by two bridging 2-naphthoxyacetate anions, one terminal 2-naphth-oxy-acetate anion and one water mol-ecule in a distorted ZnO(4) tetra-hedral geometry. The naphthalene system of the bridging ligand is nearly perpendicular to the naphthalene of the terminal ligand, with a dihedral angle of 78.

Synthesis and fluorescence properties of lanthanide(III) complexes of a novel bis(pyrazolyl-carboxyl)pyridine-based ligand.

A novel bis-pyrazolyl-carboxyl ligand, 2,6-bis(5-methyl-3-carboxypyrazol-1-ylmethyl)pyridine (L), was designed and synthesized and its several lanthanide(III) complexes Eu(III), Tb(III), Sm(III) and Gd(III) were successfully prepared and characterized in detail based on elemental analysis, infrared, mass, proton nuclear magnetic resonance spectroscopy and TG-DTA studies. Analysis of the IR spectra suggested that each of the lanthanide metal ions coordinated to the ligand via the carbonyl oxygen atoms and the nitrogen atom of the pyridine ring and pyrazole rings. The fluorescence spectra exhibits that the Tb(III) complex and the Eu(III) complex display characteristic metal-centered fluorescence in solid state while ligand fluorescence is completely quenched.

Rapid microwave synthesis of chitosan modified carbon nanotube composites.

Chitosan modified multi-walled carbon nanotube composites were synthesized under microwave irradiation. The resultant chitosan modified multi-walled carbon nanotube composites were purified by twice adjusting of pH value of the solution and centrifugating in succession. The surface functional groups of chitosan modified multi-walled carbon nanotube composites are confirmed by Fourier transform infrared spectroscopy and UV-vis spectroscopy.

Adsorption characteristics of poly(styrene-co-divinylbenzene) resin functionalized with methoxy and phenoxy groups for phenol.

Two macroporous crosslinked poly(styrene-co-divinylbenzene) resins functionalized with methoxy and phenoxy groups, PVBME and PVBPE were prepared and their adsorption characteristics for phenol were studied in hexane as well as in aqueous solution. It was shown that the equilibrium adsorption capacity of phenol onto PVBPE was a little larger than that onto PVBME at the same temperature and equilibrium concentration. The adsorption onto PVBME in hexane can be correlated to Langmuir isotherm model, whereas the semi-empirical Freundlich isotherm model characterized the adsorption onto PVBPE better.

Furanoeremophilanes from Ligularia atroviolacea.

A new furanoeremophilane, 1alpha-chloro-6beta-isobutyroxy-9-oxo-10beta-hydroxy-furanoeremophilane (1) was isolated from the root of Ligularia atroviolacea and identified mainly on the basis of detailed spectral analyses including X-ray. Moreover, five known furanoeremophilanes,1alpha-hydroxy-6beta-isobutyroxy-9-oxo-10beta-H-furanoeremophilane (2), 1alpha-hydroxy-6beta-isobutyroxy-9-oxo-10alpha-H-furanoeremophilane (3), 1alpha,10beta-dihydroxy-6beta-angeloyloxy-9-oxo-furanoeremophilane (4), furanoeremophil-3-en-15,6alpha-olide (5) and furanoeremophil-15beta,6alpha-olide (6) were isolated from the same source.

Application of high-speed counter-current chromatography for the isolation of antiviral eremophilenolides from Ligularia atroviolacea.

Ligularia is mainly distributed in the western regions of China. Most of the species have been traditionally used in folk medicine for the treatment of hepatitis B, asthma, hemoptysis and pulmonary tuberculosis. In our continuation of research on antiviral components from traditional Chinese medicine, Ligularia atroviolacea was tested for inhibitory effects on hepatitis B virus (HBV).

Preparation and characterization of Saccharomyces cerevisiae alcohol dehydrogenase immobilized on magnetic nanoparticles.

The covalently immobilized of Saccharomyces cerevisiae alcohol dehydrogenase (SCAD) to magnetic Fe(3)O(4) nanoparticles via glutaraldehyde coupling reaction was studied. The magnetic Fe(3)O(4) nanoparticles were prepared by hydrothermal method using H(2)O(2) as an oxidizer. Functionalization of surface-modified magnetic particles was performed by the covalent binding of chitosan onto the surface.

Comparative analysis of the volatile components in cut tobacco from different locations with gas chromatography-mass spectrometry (GC-MS) and combined chemometric methods.

A combined approach of subwindow factor analysis and orthogonal projection resolution was used to analyze the volatile components of cut tobacco samples from different sources. After extracted with simultaneous distillation and extraction method, the volatile components in cut tobacco from five different locations were detected by GC-MS. Then, the qualitative and quantitative analysis of the volatile components of cut tobacco from Changde area was completed with the help of subwindow factor analysis resolving two-dimensional original data into pure mass spectra and chromatograms.

Theoretical studies on novel main group metallocene-like complexes involving planar hexacoordinate carbon eta6-B6C2- ligand.

The geometric structures for a novel series of main group 1 and 2 metal atom complexes with planar hexacoordinate carbon dianion (eta6-B6C)2- ligand, involving metallocene-like, K[(eta6-B6C)Ca]n(eta6-B6C)K (n = 1-3) and [(eta6-B6C)Ca]n(eta6-B6C)2- (n = 1, 2), as well as relative pyramidal [(eta6-B6C)M]i- (M = Na, K, and CaCl, i = 1; M = Ca, i = 0) and bipyramidal (eta6-B6C)(CaCl)2, have been optimized to be the local minima on the corresponding potential hypersurfaces at the B3LYP/6-311+G(d) level of theory. Natural bond orbital analysis indicates that the electrostatic interaction between the metal ions and the planar hexacoordinate carbon B6C2- rings plays a crucial role in stabilizing these highly symmetrical complexes. The pi-d interaction in Ca-containing complexes also plays an important role in the stabilization of these molecules.

Fingerprint developing of coffee flavor by gas chromatography-mass spectrometry and combined chemometrics methods.

In this paper, chromatographic fingerprint was firstly used for quality control of tobacco flavors. Based on gas chromatography-mass spectrometry (GC-MS) and combined chemometrics methods, a simple, reliable and reproducible method for developing chromatographic fingerprint of coffee flavor, one of tobacco flavors, was described. Six coffee flavor samples obtained from different locations were used to establish the fingerprint.

Preparation and properties of modified chitosan as potential matrix materials for drug sustained-release beads.

Modified chitosan such as chitosan alpha-ketoglutaric acid (KCTS) and hydroxamated chitosan alpha-ketoglutaric acid (HKCTS) were successfully prepared. The modified chitosan were employed in the formation of drug-loaded, iron(III)-crosslinked polymeric beads. The produced polymers were characterized by IR, NMR, WXRD and DSC measurements.

Preparation and characterization of glutaraldehyde cross-linked O-carboxymethylchitosan microspheres for controlled delivery of pazufloxacin mesilate.

O-carboxymethylchitosan (OCMC) microspheres containing an antibiotic drug pazufloxacin mesilate (PM) have been successfully prepared by emulsion cross-linking using glutaraldehyde (GA). Various manufacturing parameters, including amount of cross-linking agent and OCMC:PM ratios were altered to optimize process variables during the microspheres production. The structure and morphology were characterized by Fourier transform infrared (FT-IR), wide-angle X-ray diffraction (WXRD) and scanning electron microscopy (SEM).

Mechanisms and kinetics of chelating reaction between novel chitosan derivatives and Zn(II).

Modified chitosan such as chitosan alpha-ketoglutaric acid (KCTS) and hydroxamated chitosan alpha-ketoglutaric acid (HKCTS) are successfully prepared. The resulting polymers were characterized by 13C NMR and X-ray diffraction (XRD), respectively. A adsorption system was applied to study the adsorption of Zn(II) ion onto chitosan derivatives.

A rapid, simple, specific liquid chromatographic-electrospray mass spectrometry method for the determination of finasteride in human plasma and its application to pharmacokinetic study.

A fast, accurate, sensitive, selective and reliable method using reversed-phase high-performance liquid chromatography-mass spectrometry coupling with an electrospray ionization interface was developed and validated for the determination of finasteride in human plasma. After deprotienation with acetonitrile, centrifugation, evaporation to dryness and dissolving in mobile phase, satisfactory separation was achieved on a Hypersil-Keystone C(18) reversed-phase column using a mobile phase consisting of acetonitrile-water (46:54, v/v), 0.1% acetic acid and 0.

Possible magnetic multifunctional nanoplatforms in medicine.

Recently, magnetic nanoparticles have attracted attention because of their potential in biomedicine. They can be applied to special medical techniques, such as separation, immunoassay, magnetic resonance imaging (MRI), drug delivery, and hyperthermia, and so on. But these nanoparticles only have one or two kinds of functions and cannot realize multipurpose.

Poly[[diaquacadmium(II)]-mu4-[N-(phosphonatomethyl)ammonio]acetato].

The title compound, [Cd(C3H6NO5P)(H2O)2]n, is a three-dimensional polymeric complex. The asymmetric unit contains one Cd atom, one N-(phosphonomethyl)glycine zwitterion [(O-)2OPCH2NH2+CH2COO-] and two water molecules. The coordination geometry is a distorted CdO6 octahedron.

Kinetics of adsorption of Zn(II) ion on chitosan derivatives.

The adsorption of Zn(II) ions from aqueous solution by chitosan derivatives (KCTS and HKCTS) was studied in a batch adsorption system. The adsorption capacities and rates of Zn(II) ions onto chitosan derivatives were evaluated. The adsorption isothermal data could be well interpreted by the Langmuir and Freundlich models.

Synthesis and herbicidal activity of 2-(7-fluoro-3-oxo- 3,4-dihydro-2H-benzo[b][1,4]oxazin-6-yl)isoindoline-1,3-diones.

The mode of action of 2-(7-fluoro-3-oxo-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-yl)-4,5,6,7-tetrahydro-2H-isoindoline-1,3-diones, including the commercial herbicide flumioxazin, had been identified as inhibition of protoporphyrinogen oxidase (protox). As part of continuous efforts to search for new herbicides with high efficacy, broad-spectrum activity, and safety to crops, flumioxazin and its iodo analogue (B2055) were used as lead compounds for further optimization. Series of novel compounds were prepared by multistep synthetic procedures starting from 5-fluoro-2-nitrophenol.