Tingguo Kang

Liaoning Universtity of Traditional Chinese Medicine, Feng-t’ien, Liaoning, China

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Publications (23)39.5 Total impact

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    ABSTRACT: We report a new super-concentrated HCl system prepared by using trioctylphosphine oxide (TOPO)-based reverse micelles. The observed molar ratio between acid and water (nHCl/nH2O) in the super-concentrated HCl are much higher than that in the saturated aqueous HCl solution (0.28). Moreover, FT-IR spectroscopic results reveal that a significant amount of HCl remains in the molecular form rather than being ionized into H(+) and Cl(-). As a result, two HCl stretching bands can be observed in the FT-IR spectrum. The super-concentrated HCl provides a unique chemical environment in which many chemical substances occur in unusual states. For example, the color of super-concentrated HCl solution containing copper ion was found to be reddish brown rather than green as in conventional state. UV-Vis-NIR spectral results indicate that both d-d transition band of Cu(2+) and charge transfer band of ClCu in super-concentrated HCl underwent significant variation. Additionally, copper ions bring about remarkable variation on the hydrogen bond network among HCl in the super-concentrated HCl solution as demonstrated by FT-IR spectra. According to the EXAFS results, we suggest that copper ion may occur as HCuCl3 in the super-concentrated HCl. Copyright © 2014 Elsevier B.V. All rights reserved.
    Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 02/2015; 136 Pt B:288-94. · 2.13 Impact Factor
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    ABSTRACT: We applied a newly developed technique of DAOSD (double asynchronous orthogonal sample design) approach to probe weak coordination between Nd3+ ions and ethyl acetate. Cross peaks from the 2D asynchronous spectra are successfully used to reveal subtle spectral variation on carbonyl band of ethyl acetate and f–f transition peak of Nd3+, which is relevant to the coordination between Nd3+ and the ester group of ethyl acetate. In addition, we also use 13C NMR spectra to investigate the Nd3+/ethyl acetate system. The appearance of new weak carbonyl peak around 177.8 ppm provides alternative evidence of the weak coordination between Nd3+ and ester group of ethyl acetate.
    Journal of Molecular Structure 07/2014; 1069:205–210. · 1.60 Impact Factor
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    ABSTRACT: Vitexin-4″-O-glucoside (VOG) was herein isolated from the leaves of Crataegus pinnatifida Bge. var. major, and then a sensitive and specific high performance liquid chromatography (HPLC) method was developed and validated for studying the pharmacokinetics and tissue distribution of VOG after oral and intravenous administration at a dose of 30 mg/kg. The results indicated that VOG was rapidly and widespreadly distributed throughout the whole body after administration and the oral bioavailability was 11.97 ± 0.66%. The highest VOG level after oral administration was observed in gallbladder, followed by stomach and small intestine. Whilst, the highest VOG level after intravenous administration was found in gallbladder, followed by liver and small intestine.
    Journal of Liquid Chromatography &amp Related Technologies 04/2014; 37(7). · 0.64 Impact Factor
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    ABSTRACT: PPIs are mainly metabolized by CYP2C19. It has a stereoselectivity effect on R- and S-isomer of PPIs according to previous studies. However, no study has been reported to elucidate the binding mechanism at the atomic level based on the CYP2C19 crystal structure. Recently, the advent of the first crystal structure of CYP2C19 allowed us to take in silico approaches including MD simulation, MM/GBSA calculation, energy decomposition and alanine scanning to explore the stereoselectivity of CYP2C19 on R- and S-isomer of PPIs. The key residues responsible for the selective binding for R- and S-isomers of omeprazole, lansoprazole and pantoprazole are disclosed by free energy and alanine scanning analysis. Structural analysis showed that chiral isomers of PPIs alter their conformations in order to have strong binding affinities with CYP2C19. Furthermore, a theoretical pharmacophore model of PPIs was obtained with the importance of pharmacophore feature being weighted, basing on our results. Our results are valuable for designing and synthesizing new generation of PPIs in the future. This article is protected by copyright. All rights reserved.
    Chemical Biology &amp Drug Design 12/2013; · 2.51 Impact Factor
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    ABSTRACT: Hawthorn leaves, a well-known traditional Chinese medicine, have been widely used for treating cardiovascular and fatty liver diseases. The present study aimed to investigate the therapeutic basis treating fatty liver disease by comparing the tissue distribution of six compounds of hawthorn leaf extract (HLE) in fatty liver rats and healthy rats after oral administration at first day, half month and one month, separately. Therefore, a sensitive and specific HPLC method with internal standard was developed and validated to determine chlorogenic acid, vitexin-4''-O-glucoside, vitexin-2''-O-rhamnoside, vitexin, rutin and hyperoside in the tissues including heart, liver, spleen, kidney, stomach and intestine. The results indicated that the six compounds in HLE presented some bioactivity in treating rat fatty liver as the concentrations of the six compounds varied significantly in inter- and intragroup comparisons (healthy and/or fatty liver group). Copyright © 2013 John Wiley & Sons, Ltd.
    Biomedical Chromatography 11/2013; · 1.95 Impact Factor
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    ABSTRACT: Neural stem cells (NSCs) have therapeutic potential in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS); however, to date, their use has resulted in only limited clinical and pathological improvement. To enhance their therapeutic capacity, in the present study, we transduced bone marrow-derived NSCs (BM-NSCs) with neurotrophin 3 (NT-3), a potent neurotrophic factor that is both neuroprotective and immunomodulatory. We found that BM-NSCs transduced with NT-3 reduced central nervous system (CNS) inflammation and neurological deficits in ongoing EAE significantly more than conventional NSC therapy, and, in addition, had the following advantages: (i) enhanced BM-NSC proliferation and differentiation into oligodendrocytes and neurons, as well as inhibited differentiation into astrocytes, thus promoting remyelination and neuronal repopulation, and reducing astrogliosis; (ii) enhanced anti-inflammatory capacity of BM-NSCs, thus more effectively suppressing CNS inflammation and accelerating remyelination; (iii) the easy accessibility of BM-NSCs provides another advantage over brain-derived NSCs for MS therapy; and (iv) a novel Tet-on system we used enables efficient control of NT-3 expression. Thus, our study provides a novel approach to break the vicious inflammation-demyelination cycle, and could pave the way to an easily accessible and highly effective therapy for CNS inflammatory demyelination.Molecular Therapy (2013); doi:10.1038/mt.2013.241.
    Molecular Therapy 10/2013; · 6.43 Impact Factor
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    ABSTRACT: Potassium channels participate in many critical biological functions and play important roles in a variety of diseases. In recent years, many significant discoveries have been made which motivate us to review these achievements. The focus of our review is mainly on three aspects. Firstly, we try to summarize the latest developments in structure determinants and regulation mechanism of all types of potassium channels. Secondly, we review some diseases induced by or related to these channels. Thirdly, both qualitative and quantitative approaches are utilized to analyze structural features of modulators of potassium channels. Our analyses further prove that modulators possess some certain natural product scaffolds. And pharmacokinetics parameters are important properties for organic molecules. Besides, with in silico methods, some features which can be used to differentiate modulators are derived. There is no doubt that all these studies on potassium channels as possible pharmaceutical targets will facilitate future translational research. All the strategies developed in this review could be extended to studies on other ion channels and proteins as well. This article is protected by copyright. All rights reserved.
    Chemical Biology &amp Drug Design 10/2013; · 2.51 Impact Factor
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    ABSTRACT: This paper was to clarify the reasons of low bioavailability of vitexin-4″-O-glucoside (VOG) in rats via hepatic combined with gastrointestinal first-pass effect. Observed the hepatic first-pass effect through the comparison of area under the plasma concentration-time curve from zero to infinity (AUC0→∞ ) of VOG in arterial plasma after femoral and portal vein administration (10 mg/kg), similarly, evaluated the gastrointestinal first-pass effect after portal vein (10 mg/kg) and gastrointestinal administration (20 mg/kg). For the study on regulatory mechanisms of cytochrome P450 3A (CYP3A) and P-glycoprotein (P-gp) on the bioavailability of VOG, the solution of verapamil hydrochloride (60 mg/kg) was instilled into intestine at 10 min before the infusion of VOG. The bioavailability of VOG after intraportal, intestinal as well as gastric administration was 45.1%, 8.1% and 9.8%, respectively. The value of AUC0→∞ for verapamil group was approximately 1.4-fold higher than that for normal saline group, meaning that perhaps CYP3A participated in the metabolism of VOG or P-gp transported VOG outside. The hepatic and intestinal first-pass effect were considered to mostly contribute to the low bioavailability of VOG in rats, and the gastric first-pass effect should be neglected. Also, the contribution of CYP3A to metabolism and P-gp mediated efflux have played a significant role in low bioavailability of VOG.
    The Journal of pharmacy and pharmacology. 10/2013; 65(10):1500-7.
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    ABSTRACT: Accumulation of β-amyloid peptide (Aβ) in the brain plays an important role in the pathogenesis of Alzheimers disease (AD). Previous studies have demonstrated the neuroprotective role of osthole against oxygen and glucose deprivation in cortical neurons. However, the effects of osthole on A-induced neurotoxicity in neural cells have rarely been reported. The current study was designed to investigate the protective effects of osthole on a cell model of AD insulted by exogenous Aβ25-35 and the potential mechanism(s). In this study, MTT assay, immunofluorescence analysis, apoptosis assay, RT-PCR and ELISA techniques were used in primary cortical neurons and SH-SY5Y cells. Our data showed that osthole reduced intracellular Aβ levels in neural cells, which was associated with decreased BACE1 protein; osthole reversed exogenous Aβ25-35-induced cell viability loss, apoptosis, and synapsin-1 reduction, which was related to the reestablishment of phosphorylation of cyclic AMP response element-binding protein (CREB). The collective evidence indicates that osthole possesses the ability to protect cortical neurons and SH-SY5Y cells against Aβ injury, and the underlying mechanism may be attributed to the enhancement of CREB phosphorylation.
    Biological & Pharmaceutical Bulletin 09/2013; · 1.85 Impact Factor
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    ABSTRACT: Arctigenin (Arc) has been shown to act on scopolamine-induced memory deficit mice and to provide a neuroprotective effect on cultured cortical neurons from glutamate-induced neurodegeneration through mechanisms not completely defined. Here, we investigated the neuroprotective effect of Arc on H89-induced cell damage and its potential mechanisms in mouse cortical neurons and human SH-SY5Y neuroblastoma cells. We found that Arc prevented cell viability loss induced by H89 in human SH-SY5Y cells. Moreover, Arc reduced intracellular beta amyloid (Aβ) production induced by H89 in neurons and human SH-SY5Y cells, and Arc also inhibited the presenilin 1(PS1) protein level in neurons. In addition, neural apoptosis in both types of cells, inhibition of neurite outgrowth in human SH-SY5Y cells and reduction of synaptic marker synaptophysin (SYN) expression in neurons were also observed after H89 exposure. All these effects induced by H89 were markedly reversed by Arc treatment. Arc also significantly attenuated downregulation of the phosphorylation of CREB (p-CREB) induced by H89, which may contribute to the neuroprotective effects of Arc. These results demonstrated that Arc exerted the ability to protect neurons and SH-SY5Y cells against H89-induced cell injury via upregulation of p-CREB.
    International Journal of Molecular Sciences 09/2013; 14(9):18657-69. · 2.34 Impact Factor
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    ABSTRACT: The aim of this study is to develop a simple and specific HPLC method using vitexin as the internal standard to investigate the pharmacokinetics of isoquercitrin (ISOQ) after three different doses administrated intravenously to rats. The pharmacokinetic parameters were calculated by both compartmental and non-compartmental approaches. The results showed that ISOQ fitted a three-compartment open model. The values of AUC increased proportionally within the range of 5-10 mg·kg-1. Moreover, a half-life, b half-life, ªCL, MRT0-t and MRT0→∞ of ISOQ in rats showed significant differences between 20 mg·kg-1 and other doses, indicating that ISOQ presented dose-dependent pharmacokinetics in the range of 5-10 mg·kg-1 and non-linear pharmacokinetics at higher doses.
    Brazilian Journal of Pharmaceutical Science 09/2013; 49(3):435-441. · 0.30 Impact Factor
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    ABSTRACT: Our previous study has demonstrated the therapeutic potential of bone marrow derived-neural stem cells (BM-NSCs) in CNS disorders; however, the beneficial effects are modest due to the poor survival and low neural differentiation frequency. Here, we demonstrate that Salvianolic acid B (Sal B), a potent aqueous of a well known Chinese medicine herb, Salvia miltiorrhiza, possesses the ability to promote BM-NSCs proliferation in a dose dependent manner as verified by growth curve and Bromodeoxyuridine (BrdU) incorporation assays; While in differentiation medium, Sal B promoted nestin(+) BM-NSCs differentiated into greater numbers of NF-M(+) neurons and NG2(+) oligodendrocyte precursors, but fewer GFAP(+) astrocytes as verified by triple immunostaining and quantitive analysis; upon exposure to H(2)O(2), Sal B facilitated the cells survival, reduced LDH leakage and inhibited apoptosis, displaying a dose-dependent neuroprotective effects on BM-NSCs. Sal B induced brain-derived neurotrophic factor (BDNF) production by BM-NSCs, which may be beneficial for the cells survival and differentiation in unfavorable environment. The collective evidence indicates that Sal B may be a potential drug to upgrade the therapeutic efficiency of BM-NSCs in CNS diseases.
    European journal of pharmacology 10/2012; · 2.59 Impact Factor
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    ABSTRACT: A comparative study was performed to identify the microscopic characteristics of hair or feather in the five animal drug components contained in Shenrongbian pill. Penis et Testis Canis is 40±0.07 in the medulla index, with long circular, banana or triangular circular shaped medulla cells arranged in one line or network, and the hair cuticle is in imbrication (d, m) and flat wave (p) shape. Penis et Testis Equi is 66±0.10 in the medulla index, with ellipse, spindle or long strip-shaped medulla cells arranged in network, and the hair cuticle is in flat wave shape. Penis et Testis Bovis is 67±0.05 in the medulla index, with rectangle, spindle or polygon-shaped medulla cells arranged in ladder or network form, and the hair cuticle is in flat wave shape. Penis et Testis Mustelae is 29±0.05 in the medulla index, with ellipse-like, square-like or circular shaped medulla cells arranged in one line generally, and the hair cuticle is in acuminate (d, m), imbrication (m,p) and slightly flat wave (p) shape. Musculus et Bonis Passeris is 24±0.05 in the medulla index, with bamboo joint-shaped barbs and unclear medulla cells, without hair cuticle.
    Acta Pharmaceutica Sinica B. 06/2012; 2(3):306–311.
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    ABSTRACT: The suppressive effect of neural stem cells (NSCs) on experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS), has been reported. However, the migration of NSCs to inflammatory sites was relatively slow as was the onset of rather limited clinical benefit. Lack of, or low expression of particular chemokine receptors on NSCs could be an important factor underlying the slow migration of NSCs. To enhance the therapeutic effect of NSCs, in the present study we transduced bone marrow (BM)-derived NSCs with CCR5, a receptor for CCL3, CCL4, and CCL5, chemokines that are abundantly produced in CNS-inflamed foci of MS/EAE. After i.v. injection, CCR5-NSCs rapidly reached EAE foci in larger numbers, and more effectively suppressed CNS inflammatory infiltration, myelin damage, and clinical EAE than GFP-NSCs used as controls. CCR5-NSC-treated mice also exhibited augmented remyelination and neuron/oligodendrocyte repopulation compared to PBS- or GFP-NSC-treated mice. We inferred that the critical mechanism underlying enhanced effect of CCR5-transduced NSCs on EAE is the early migration of chemokine receptor-transduced NSCs into the inflamed foci. Such migration at an earlier stage of inflammation enables NSCs to exert more effective immunomodulation, to reduce the extent of early myelin/neuron damage by creating a less hostile environment for remyelinating cells, and possibly to participate in the remyelination/neural repopulation process. These features of BM-derived transduced NSCs, combined with their easy availability (the subject's own BM) and autologous properties, may lay the groundwork for an innovative approach to rapid and highly effective MS therapy.
    Acta Neuropathologica 04/2012; 124(4):491-503. · 9.78 Impact Factor
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    ABSTRACT: The objective of the present study was to develop a simple and selective HPLC method for the simultaneous determination of hesperidin (HP), caffeic acid (CA), ferulic acid (FA) and p-coumaric acid (p-CA) in rat plasma after intravenous administration of Portulaca oleracea L. extract (POE). With the hyperoside as the internal standard, the sample pretreatment procedure involved simple single-step extraction with methanol of 0.2 mL plasma. The mobile phase consisted of methanol-acetonitrile-tetrahydrofuran-0.5% glacial acetic acid (5:3:18:74, v/v/v/v). The calibration curves were linear over the range of 0.1-25 µg mL-1, 0.1-25 µg mL-1, 0.1-25 µg mL-1and 0.015-3 µg mL-1 for HP, CA, FA and p-CA, respectively. The method developed was suitable for the pharmacokinetic study of HP, CA, FA and p-CA in rats after intravenous administration of POE.
    Brazilian Journal of Pharmaceutical Science 03/2012; 48(1):163-170. · 0.30 Impact Factor
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    ABSTRACT: This study investigated the pharmacokinetics of hesperidin (HP), ferulic acid (FA) and p-coumaric acid (CA) in rat plasma after oral administration of Portulaca oleracea L. extract (POE). The plasma concentrations were determined by HPLC with vitexin-2″-O-rhamnoside (VR) as internal standard. The calibration curves were linear over the range 0.1-5 µg mL(-1), 0.1-5 µg mL(-1)and 0.015-3 µg mL(-1) for HP, FA and CA, respectively. The validated method was suitable to the pharmacokinetic study of HP, FA and CA in rats after oral administration at a single dose of POE.
    Natural product research 01/2012; 26(23):2247-50. · 1.23 Impact Factor
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    ABSTRACT: A simple and sensitive HPLC method was developed to simultaneously determine three active compounds, vitexin-4″-O-glucoside (VG), vitexin-2″-O-rhamnoside (VR) and hyperoside (HP), in rat plasma after administering the hawthorn leaves extract (HLE). An HPLC assay with baicalin as the internal standard was carried out using a Phenomsil C₁₈ analytical column with UV detection at 332 nm. The mobile phase consisted of methanol-acetonitrile-tetrahydrofuran-1% glacial acetic acid (6 : 1.5 : 18.5 : 74, v/v/v/v). The calibration curves were linear over the range of 2.5-500, 0.2-25 and 0.25-12.5 µg mL⁻¹ for VG, VR and HP, respectively. The method was reproducible and reliable, with relative standard deviations of the intra- and inter-day precision between 1.2% and 13.2% for the analysis of the three analytes. The validated HPLC method herein described was successfully applied to the pharmacokinetic study of VG, VR and HP after oral administration of HLE to rats over the dose range of 2.5-10  mL kg⁻¹.
    Natural product research 08/2011; 26(6):585-91. · 1.23 Impact Factor
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    ABSTRACT: A simple and specific high-performance liquid chromatography (HPLC) method was developed for the pharmacokinetic study of vitexin-4″-O-glucoside (VOG) in rats after oral administration. The plasma samples were deproteinised with methanol after the addition of an internal standard, hesperidin. HPLC analysis was performed on a Diamonsil C(18) analytical column, using methanol -0.5% aqueous phosphoric acid (45:55, v/v) as the mobile phase with ultraviolet detection at 330 nm. The calibration curve was linear over the range of 5-450 µg mL(-1) in rat plasma. The average extraction recovery of VOG was 98.74% ± 0.44%, and the relative standard deviations of the intra- and inter-day precisions were not greater than 4.1% and 2.0%, respectively. The validated method was successfully applied during a pharmacokinetic study in rats after oral administration of VOG at different doses, and all the results indicated that the pharmacokinetics of VOG in rats obeyed nonlinear processes.
    Natural product research 08/2011; 26(10):962-7. · 1.23 Impact Factor
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    ABSTRACT: The roots, barks, branches and pericarps of Juglans mandshurica were used as folk medicine in China and reputed for its treatment of several cancers, such as gastric cancer, liver cancer and leukemia. The extracts of the roots, branches, leaves and pericarps of J. mandshurica have been experimentally proved to show anti-tumor activities. Tannins, which exhibited antioxidant and anti-tumor activities, were the main constituents in J. mandshurica. In this paper, a simple spectrophotometric method was developed for the determination of total tannins in the roots, branches, leaves and pericarps of J. mandshurica collected in Dalian and Anshan of Liaoning Province. Gallic acid was used as standard compound and the content of total tannins was calculated as gallic acid equivalent. As a result of the method validation, a good linearity (r = 0.9997, n = 5) and a high recovery of gallic acid (99.02%, RSD 3.7%, n = 9) was achieved. Eight samples including four parts of J. mandshurica collected in two places were analyzed for their total tannins with the established method. In the corresponding parts of J. mandshurica, except the pericarps, the contents of total tannins showed no significant difference between samples collected in Dalian and Anshan, while the content of total tannins in different parts of J. mandshurica were significantly different. The average content of total tannins in the roots, branches, leaves and pericarps of samples collected in Dalian and Anshan was 45.66, 23.40, 58.24, 3.58 mg g(-1), respectively.
    Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica 01/2011; 36(1):32-6.
  • Ruixin Zhu, Ming Xie, Fei Wang, Qi Liu, Tingguo Kang
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    ABSTRACT: The arginine derivative Fmoc-Argω,ω′(Boc)2-OH has been prepared in perfect yield starting from Fmoc-Orn·HCl and N,N′-di-Boc-N′′-triflyguanidine with the presence of diisopropylethylamine (DIEA). This work provides an efficient and economical method for the preparation of this compound.
    Chinese Journal of Chemistry 08/2010; 28(8). · 0.92 Impact Factor