Anti-lipid peroxidation and protection of liver mitochondria against injuries by picroside Ⅱ

AIM: To investigate the anti-lipid peroxidation and protection of liver mitochondria against injuries in mice with liverdamage by picroside Ⅱ.METHODS: Three animal models of liver damageinduced by carbon tetrachloride (CCl4:0.1 mL/10 g, ip),D-galactosamine (D-GalN: 500 mg/kg,ip) and acetaminophen (AP: 0.15 g/kg, ip) were respectively treated with various concentrations of picroside Ⅱ (5, 10, 20 mg/kg, ig). Then we chose the continuously monitoring method (recommended by International Clinical Chemistry League) to analyze serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) values, Marland method to detect the activity of manganese-superoxide dismutase (SOD) in liver mitochondria, TBA colorimetry to determine the content of malonicdialdehyde (MDA) in liver tissue, DTNB method to evaluate the activity of glutathioneperoxidase (GSH-Px) and Lowry method to detect protein level in liver tissue. Meanwhile, effects of picroside Ⅱ on the activity of ATPase and swelling extent of mitochondria in hepatocytes damaged by AP were also evaluated.RESULTS: Picroside Ⅱ could significantly prevent liver toxicity in the three models of liver damage. It decreased the high levels of ALT and AST in serum induced by theadministration of CCl4, D-GalN and AP, reduced the cellular damage of liver markedly, and appeared to be even more potent than the positive control drug of biphenyl dimethyl dicarboxylate pilules (DDB). In groups treated with different doses of picroside Ⅱ, compared to the model group, the content of MDA in serum decreased evidently, whereas the content of SOD and GSH-Px increased in a dosedependent manner, and the difference was statistically significant. Further, in the study of AP model, picroside Ⅱinhibited AP-induced liver toxicity in mice, enhanced the activity of ATPase, improved the swelling extent of mitochondria and helped to maintain a normal balance of energy metabolism.CONCLUSION: Picroside Ⅱ can evidently relieve hepatocyteinjuries induced by CCl4, D-GalN and AP, help scavenge free radicals, protect normal constructions of mitochondria membrane and enhance the activity of ATPase in mitochondria,thereby modulating the balance of liver energy metabolism, which might be part of the mechanisms of hepatoprotectiveeffects of picroside Ⅱ.

Production and Characterization of Anti-estrone Monoclonal Antibody

Objective Determination of estrone (E1) levels has a significant meaning in evaluating physiological effect and diagnosing some diseases. In order to detect free E1 in biological fluids, a monoclonal antibody specific for E1 was prepared after the complete antigen of E1 was synthesized. The purified monoclonal antibody was fully characterized for later immunoassay. Methods 3-O-carboxymethyl ether derivative of E1 was synthesized and in turn coupled to bovine serum albumin (BSA) to form complete antigen E1-BSA. A monoclonal antibody (McAb) specific for E1 was produced both in vitro and in vivo by a hybridoma anti-E1. Anti-E1 was prepared by fusion of SP2/0 murine myeloma cells with spleen cells isolated from immunized BALB/c mouse. The McAb was characterized by enzyme-linked immunosorbent assay (ELISA), SDS-PAGE and Western-blotting. The specificity of the immunoassay was investigated by determining the cross-reactions of E1 analogs when free E1 was detected by competitive indirect enzyme-linked immunosorbent assay (CI-ELISA). Results Analysis revealed that anti-E1 McAb (E1-McAb) was of the IgG1 type, the molecular weight of E1-McAb was 164 000 daltons. The affinity constant of E1-McAb with coated complete antigen was 8.2108L/mol. The linear range for free E1 determined by CI-ELISA was 10pg/mL^10ng/mL. The detection limit was 21.4 pg/mL (defined as twice the standard deviation of the blank). Conclusion The CI-ELISA developed with E1-McAb was both sensitive and specific. The prepared E1-McAb can be used in some immunoassays.

Studies on the Recognition Interaction of Rhodamine B and DNA by Voltammetry

The recognition interaction of Rhodamine B(RB) with DNA was studied in a Britton-Robinson (B-R) buffer solution with pH=7.5 at a glassy carbon electrode by electrochemical techniques. RB shows an irreversible oxidation peak at +0.92 V(vs. SCE). After the addition of DNA in the RB solution, the peak current of RB decreased apparently without the shift of the peak potential. The electrochemical parameters such as the charge transfer coefficient α and the electrode reaction rate constant k s of the interaction system were carefully studied. The parameters did not change before and after the addition of DNA, which indicated that an electrochemical non-active complex had been formed, so the concentration of RB in the solution decreased and the peak current decreased correspondingly. The binding ratio of RB to DNA was 2∶1 with a binding constant of 2.66×10 9.

Liquid-liquid Extraction System Based on Non-ionic Surfactant-salt-H_2O and Mechanism of Drug Extraction

Extraction behavior of chlorpromazine hydrochloride (CPZ) and procaine hydro- chloride (PCN) in the system described in the title was studied. Research shows that the extraction efficiency of CPZ can amount to 96% by twice extraction, while that of PCN is 77%. This system produces the distribution coefficients (KD) of 12.3 and 2.6 respectively for CPZ and PCN. Extraction mechanism is deduced according to ultraviolet and molecular fluorescence spectra variation of the drugs in the system studied.

Electrochemical Study on the Interaction Between Neutral Red and DNA

A voltammetric study of the interaction of neutral Red(NR) with DNA at a gold electrode in a phosphate buffer solution is described. After adding DNA in an NR solution, the reduction peak current of NR decreases. The binding mechahisms of NR to DNA in different pH ranges are different. The reduction peak potential of NR in a pH 7.0 phosphate buffer solution in the presence of DNA shifts positively, indicating that the binding of NR to DNA is intercalation action, but at pH=6.0 the reduction peak potential of NR shifts negatively, indicating that the binding of NR to DNA is electrostatic action. The formed complexes are DNA-NR when [NR]/[DNA]<0.18 and DNA-3NR when [NR]/[DNA]>0.35, respectively.

In vivo and in situ detection of colorectal cancer using Fourier transform infrared spectroscopy

AIM: Real-time and rapid identification of the malignant tissue can be performed during or before surgical operation.Here we aimed to detect in vivo and in situ colorectal cancer by using Fourier transform infrared (FTIR) spectroscopy and fiber-optic technology.METHODS: A total of five patients with large intestine cancer were detected in vivo and in situ. Of them, three cases of colon cancer and one case of cecum cancer were detected intraoperatively and in vivo by using a FTIR spectrometer during surgical operation, and one case of rectum cancer was explored non-invasively and in vivo before the surgical operation. Normal and malignant colorectal tissues were detected in vivo and in situ using FTIR spectroscopy on the basis of fundamental studies.RESULTS: There were significant differences between FTIR spectra of normal and malignant colorectal tissues detected in vivo and in situ. Experimental results revealed that the spectral characteristics of normal and malignant tissues found in vivo and in situ were similar to those obtained from in vitro measurement in our previous fundamental research.CONCLUSION: FTIR fiber-optic attenuated total reflectance (ATR) spectroscopy can identify in situ and in vivo colorectal cancer. FTIR spectroscopic method with fiber optics is a non-invasive, rapid, accurate and in vivo cancer detection technique in clinical diagnosis.

Differentiation of Constitutional Isomer of 2,2a,3,4-Tetrahydro- 4-methyl-2a-phenyl-2-(thiophen-2-yl)-1H-azeto[2,1-d][1,5] benzothiazepin-1-one-5-oxide and Fragmentations of 2,3-Dihydro- 2,4-diphenyl-1,5-benzothiazepine-1-oxide/-1,1-dioxide

Mass spectrometric behaviour of 2,2a,3,4-tetrahydro-4-methyl-2a-phenyl-2-(thiophen-2-yl)-1H-azeto[2,1-d][1,5]benzothiazepin-1-one-5-oxide and 2,3-dihydro-2,4-diphenyl-1,5-benzothiazepine-1-oxide/-1,1-dioxide have been studied with the aid of mass-analyzed ion kinetic energy spectrometry and accurate mass measurements under electron impact ionization. The monooxide derivatives showed a tendency to eliminate an alkene or an oxygen atom. 1H-Azeto[2,1-d][1,5]benzothiazepin-1-one-5-oxide could also eliminate the thiophen-2-ylketene molecule via a reverse [2+2] cycloaddition. 2,3-Dihydro-2,4-diphenyl-1,5-benzothiazepine-1-oxide/-1,1-dioxide could eliminate SO_2 or SO, respectively. The structure of 2,2a,3,4-tetrahydro-4-methyl-2a-phenyl-2-(thiophen-2-yl)-1H-azeto[2,1-d][1,5]benzothiazepin-1-one-5-oxide was identified on the basis of its fragmentation. The identification was supported by the fragmentations of model compound, 2,3-dihydro-2,4-diphenyl-1,5-benzothiazepine-1-oxide/-1,1-dioxide.

A Novel Catalyst for Liquid Phase Hydrogenation of m-Dinitrobenzene to m-Phenylenediamine

A novel lanthana-promoted nickel catalyst supported on silica for the liquid phase hydrogenation of m-dinitrobenzene to m-phenylenediamine was prepared by an incipient wetness sequential impregnation method. It was found that Ni-La/SiO2 catalyst exhibited high activity and stability for m-dinitrobenzene hydrogenation. Over this catalyst, the conversion of m-dinitrobenzene and the yield of m-phenylenediamine were up to 97.1% and 93.5%, respectively, at 373 K and 2.6 MPa hydrogen pressure after reaction for 1 h.

Photoelectrochemical Properties of Highly Oriented ZnO Nanotube Array Films on ITO Substrates

Highly oriented ZnO nanotube array films on the conducting substrates have been synthesized by a simple hydrothermal method and characterized by scanning electron microscopy (SEM) and UV-Vis spectroscopy. The thin films consisting of laterally fragmentized ZnO nanotubes with controlled orientation have been tested as photoanode in Gr鋞zel-type solar cell. For a sandwich-type cell, with 0.5 mol/L LiI and 0.05 mol/L I2 in propylene carbonate electrolyte, the overall solar energy conversion efficiency reaches 2.3%.

Separation of Biphenyl Nitrile Compounds by Microemulsion Electrokinetic Chromatography with Mixed Surfactants

A mixture of nine biphenyl nitrile compounds with high hydrophobicity and similar structures was successfully separated by microemulsion electrokinetic chromatography (MEEKC) within 30 min. The buffer system contained 100 mmol/L sodium dodecyl sulfate (SDS), 80 mmol/L sodium cholate (SC), 0.81% heptane, 7.5% n-butanol, 10% acetonitrile and 10 mmol/L borate. The addition of SC, organic modifiers, sample preparation and temperature all showed remarkable effect on the separation. Meanwhile, the MEEKC method was briefly compared with micellar electrokinetic chromatography (MEKC) method.

Use of Fourier-transform infrared spectroscopy to rapidly diagnose gastric endoscopic biopsies

AIM: To determine if Fourier-transform infrared (FT-IR)spectroscopy of endoscopic biopsies could accurately diagnose gastritis and malignancy.METHODS: A total of 123 gastroscopic samples, including 11 cases of cancerous tissues, 63 cases of chronic atrophic gastritis tissues, 47 cases of chronic superficial gastritis tissues and 2 cases of normal tissues, were obtained from the First Hospital of Xi'an Jiaotong University, China. A modified attenuated total reflectance (ATR) accessory was linked to a WQD-500 FT-IR spectrometer for spectral measurement followed by submission of the samples for pathologic analysis. The spectral characteristics for different types of gastroscopic tissues were summarized and correlated with the corresponding pathologic results.RESULTS: Distinct differences were observed in the FTIR spectra of normal, atrophic gastritis, superficial gastritis and malignant gastric tissues. The sensitivity of FT-IR for detection of gastric cancer, chronic atrophic gastritis and superficial gastritis was 90.9%, 82.5%, 91.5%, and specificity was 97.3%, 91.7%, 89.5% respectively.CONCLUSION: FT-IR spectroscopy can distinguish gastric inflammation from malignancy.

Studies of the Effects of Alkali Metal Oxides Promoter on the Oxidative Methylation of Toluene with Methane over KY Zeolite Catalysts

The toluene conversion, the selectivity to styrene and ethylbenzene( C8 selectivity) in the oxidative methylation of toluene with methane have been studied comparatively for the KY zeolite catalyst promoted with Li2O, Na2O, K2O, and Cs2O respectively. It was found that the effect of promoter decreased in the order: Cs2O>Na2O>Li2O>K2O.

Highly Efficient Photosensitization of Mesoporous TiO_2 Electrode with a Cyanine Dye

A low cost cyanine dye, 1,1-dimethyl-3-ethyl-2-[3-(1,3-dihydro-3,3-dimethyl-1-ethyl- 5-carboxyl-2H-indol-2-ylidene)-1-propenyl]-1H-benz[e] indolium iodide (1) was synthesized and applied to sensitize mesoporous TiO2 electrode. Photoresponse of the electrode was extended to the visible and remarkably high incident photon-to-current conversion efficiency (IPCE) over 70% was achieved from 500 nm to 600 nm.

Spillover on a Platinum Electrode Modified by MWNTs

The spillover phenomenon is observed on the platinum (Pt) disk electrode modified bymulti-wall carbon nanotubes (MWNTs). The rate of the spillover of oxygen-containing speciesproduced on Pt surface to and from MWNTs is fast. However for hydrogen-adatoms, thespillover is very weak. The selective spillover on the Pt/MWNTs electrode may provide a novelway to design catalysts.

Electrochemical Determination of Alkaline Phosphatase in Human Serum by Differential Pulse Voltammetry

Differential pulse voltammetry(DPV) was applied to the determination of alkaline phosphatase(ALP) activity in human serum with phenyl phosphate as the substrate. Phenyl phosphate can enzymatically be hydrolyzed to produce phenol which is quantified by DPV at +660 mV(vs.Ag/AgCl) in the concentration range of 2.0_100 μmol/L. The standard curve for ALP is linear over the range from 0.06 to 1000 U/L with a relative standard deviation of 3.0%. The conditions for the enzymatic reaction and voltammetric detection were optimized and the kinetic constants were also examined.The human serum samples were tested by this method and the results were in good agreement with those obtained by the routine p-nitrophenyl phosphate spectrophotometric method.

Organophosphorus Compound DEPBT as a Coupling Reagent for Oligopeptides and Peptoids Synthesis: Studies on Its Mechanism

Some oligopeptides and peptoids were synthesized by applying the organophosphorus compound DEPBT as a coupling reagent. D-Biotin-OOBt was obtained unexpectedly. A proposed reaction mechanism for DEPBT-mediated coupling was proved.

Synthesis and Crystal Structures of the α and β Forms of Bis(salicylaldoxime)copper(Ⅱ) Complexes

Modified α and β bis(salicylaldoxime)copper(Ⅱ) have been obtained by recrystallization from ethyl acetate(CCDC Nos. 212157 & 212158). The X-ray analysis reveals that the two modificated forms have the same structure with different geometric parameters. The α form crystallizes in the P2(1)/c space group and the β form in the P1 space group. Both the crystal structures consist of centrosymmetric monomeric molecules of Cu(OC_6H_4CNOH)_2. The IR spectra are in agreement with the structural data.

Convenient Synthesis of Bis(oxazoline) Dicarboxylate Derivatives.

The synthesis of bis(oxazoline) dicarboxylate derivatives was investigated. Diethyl-aminosulfur trifluoride (DAST) was used as a convenient cyclization reagent in the synthesis of bis(oxazoline) dicarboxylate derivatives, which can not be obtained by the general method using MsCl and Et3N as dehydrating cyclization reagent.