Biomedical subjects
Publications and source records attributed to Bo Tang.
Two novel organic-inorganic hybrid coordination polymers were synthesized based on a new multidentate Schiff-base ligand and Ag(i) salts
The coupling reaction of 4-aminoantipyrine (4-AAP) with phenol using the superoxide anion radical (O2-*) as oxidizing agent under the catalysis of horseradish peroxidase (HRP) was studied. Based on the reaction, O2-* produced by irradiating vitamin B2 (VB2) was spectrophotometrically determined at 510 nm. Under the optimum experimental conditions, the relationship between A510 and O2-* concentration was linear in the range 9.14x10(-6)-1.2x10(-4) mol L(-1). The detection limit was determined to be 1.37x10(-6) mol L(-1). A possible reaction mechanism was discussed. The effect of interferences and surfactants on the determination of O2-* was also investigated. The proposed method was applied to determine superoxide dismutase activity in garlic, scallion, and onion with satisfactory results.
1,5-bis(p-Hydroxybenzaldene)thiocarbohydrazone (BHBTZ) had been synthesized and used as a new kind of substrate for horseradish peroxidase (HRP). The experiment results showed that ascorbic acid (AsA) had strongly inhibiting effect on the BHBTZ-H(2)O(2)-HRP reaction system, so AsA had been spectrophotomericly determined as the inhibitor by enzymatic inhibition method. Under experimental conditions, the linear relationship between DeltaA(386) and AsA concentration was in the range of 0.82-18.0 microg ml(-1) with a detection limit of 0.245 microg ml(-1). The effect of interferences on AsA determination was investigated. The proposed method was successfully applied to the determination of AsA in tea drink.
Two kinds of Schiff base metal complexes of 2-hydroxy-1-naphthaldehyde-2-amino-5-phenylthiazole (HANPTS), Mn(II)(HNAPTS)(2) and Fe(III)(HNAPTS)(2), were synthesized and used to mimic the active group of horseradish peroxidase (HRP). The catalytic characteristics of the mimic enzymes in the oxidation reaction of ascorbic acid (AsA) with the OOH group in polyethylene glycols (PEGs) have been studied by a spectrophotometric method. Fe(III) has remarkable coordinated catalysis to Mn(II)(HNAPTS)(2); as a result, the catalytic ability of Fe(III)-Mn(II)(HNAPTS)(2) is 75% of that of HRP. The possible mechanism of the reaction was discussed. The linear relationship between deltaA(265)(AsA) and OOH group concentrations was in the range of 1.5 x 10(-6) to 9.0 x 10(-4) mol/L. The proposed method was successfully applied to the determination of the OOH group level in different molecular weight PEGs.
A novel host inclusion complex of beta-cyclodextrin-o-vanillin benzoylhydrazone (beta-CDP-OVBH) was prepared and characterized by IR and 1H-NMR spectra. A highly selective and sensitive fluorescent determination of trace amounts of zinc was proposed based on the reaction between Zn(2+) and beta-CDP-OVBH in sodium hydroxide-ammonium acetate buffer medium of pH 8.3. The molar ratio of beta-CDP-OVBH to Zn(2+) was 1:1. The maximum excitation and emission wavelengths were 396 and 486 nm, respectively. The linear range of this method was 2.5-500 microg l(-1) with a detection limit of 0.60 microg l(-1). The effect of interferences in the determination of zinc was investigated, the results showed that the host reagent had a quite high identifying capacity on Zn(2+). This method was successfully applied to the determination of trace amounts of Zn(2+) in tea and human hairs.
2-Hydroxy-1-naphthaldehyde thiosemicarbazon (HNT) had been synthesized and used as a new kind of substrate for horseradish peroxidase (HRP) in spectrofluorimetric determination of hydrogen peroxide (H(2)O(2)). The oxidation reaction of HNT with H(2)O(2) under the catalysis of HRP was studied in detail. The possible reaction mechanism was discussed. Under optimum experimental conditions, the oxidized product of HNT had excitation and emission maxima at 260 and 450 nm, respectively. The linear range of this method was 1.30 x 10(-9)-1.25 x 10(-5) mol l(-1) with a detection limit of 3.89 x 10(-10) mol l(-1). The effect of interferences, surfactants and organic solvents on the determination of H(2)O(2) had been investigated. A study to prove the existence of -O-O-H in PEGs was carried out. The proposed method was successfully applied to the determination of -O-O-H in polyethylene glycols.
Microsatellite markers are widely used in linkage mapping, parentage testing, population genetic studies, and molecular evolution studies in many agricultural species, while only a limited number of ostrich (Struthio camelus) microsatellites have been isolated. Thus, we constructed a random small-insert genomic library and a microsatellite-enriched library containing CA repeats. Fourteen clones containing CA repeats were isolated from 3462 clones in the non-enriched library by radioactive screening and 248 positive clones were isolated from 300 sequenced clones from the enriched library by PCR screening. After the enrichment procedures, the proportion of clones containing CA repeats was raised to 78.8%, compared with 0.4% in the non-enriched libraries, indicating that the enrichment value approaches 200 fold, which decreased the time and cost of cloning. The number of complete simple CA repeats in these positive clones ranged from 5 to 29. The primers for 94 of these microsatellites were developed and used to detect polymorphisms, of which 61 loci exhibited length polymorphisms in 17 unrelated ostrich individuals. The new polymorphic microsatellite markers we have identified and characterized will contribute to the ostrich genetic map, parentage testing, and comparative genomics between avian species.
A novel fulvene-type bidentate ligand 1 has been synthesized by an aroylation reaction of cyclohexyl-substituted cyclopentadienyl anions. Compound 1 crystallizes in the triclinic space group P(-)1, with a = 7.0419(5) A, b = 11.9360(8) A, c = 15.6470(11) A, alpha = 85.1440(10) degrees, beta = 78.1140(10) degrees, gamma = 74.5360(10) degrees, V = 1239.76(15) A(3), and Z = 2. The coordination chemistry of 1 was investigated, and a novel Ag-containing coordination polymer (2), linked by both Ag-heteroatom and Ag-carbon interactions, has been synthesized. The coordination polymer has been fully characterized by infrared spectroscopy, elemental analysis, and single-crystal X-ray diffraction. Compound 2 crystallizes in the triclinic space group P(-)1, with a = 7.1654(5) A, b = 15.7277(11) A, c = 18.8157(13) A, alpha = 73.5150(10) degrees, beta = 89.0410(10) degrees, gamma = 89.0970(10) degrees, V = 1355.19(14) A(3), and Z = 2. The solid-state structure of 2 features a one-dimensional double-chain motif. These double chains are in turn cross-linked to each other via strong interchain O-H...O hydrogen bonds, forming a novel two-dimensional network with remarkably large cavities (effective cross section of ca. 21 x 15 A) that are occupied by benzene guest molecules. Both compounds 1 and 2 are luminescent in the solid state, and a large blue-shift in the emission between the free ligand 1 and the ligand incorporated into complex 2 is observed.
The supramolecular interaction of curcumin and beta-cyclodextrin (beta-CD) has been studied by spectrophotometry. The mechanism of the inclusion was studied and discussed based on the variations of pK(a), absorption intensity, and infrared spectrograms. The results show that beta-CD reacts with curcumin to form a 2:1 host-guest complex with an apparent formation constant of 5.53 x 10(5) mol(-2) x L2. Based on the enhancement of the absorbance of curcumin produced through complex formation, a spectrophotometric method for the determination of curcumin in bulk aqueous solution in the presence of beta-CD was developed. The linear relationship between the absorbance and curcumin concentration was obtained in the range of 0-15 microg/mL, with a correlation coefficient (r) of 0.9991. The detection limit was 0.076 microg/mL. The proposed method was used to determine the curcumin in curry and mustard with satisfactory results.
The oxidation reaction of HNSH with H2O2 under the catalysis of HRP was studied in detail. The possible reaction mechanism was discussed. Under optimum experimental conditions, the oxidized product of HNSH had excitation and emission maxima at 296 and 414 nm, respectively. A study to prove the existence of -O-O-H in polyethylene glycols was carried out. The proposed method was successfully applied to the determination of -O-O-H in polyethylene glycols.
The coupled reaction of N,N-dimethylaniline (DMA) with 4-aminoantipyrine (4-AAP) using superoxide anion radical (O2-) as oxidizing agent under the catalysis of horseradish peroxidase (HRP) was studied. Based on the reaction, O2- produced by irradiating Vitamin B2, (VB2) was spectrophotometricly determined at 554 nm. The linear range of this method was 1.8 x 10(-6)-1.2 x 10(-4) mol l(-1) with a detection limit of 5.3 x 10(-7) mol l(-1). The effect of interferences on the determination of O2- was investigated. The proposed method was successfully applied to the determination of superoxide dismutase (SOD) activity in human blood and mouse blood.
Use of fluorescence spectrophotometry for the determination of procaine hydrochloride in injection solution of procaine hydrochloride in suggested based on fluorescence property of 4-aminobenzoate which is a hydrolysis product of the procaine hydrochloride in pH 12, with exciatation wavelength and emission wavelength at 268 and 340 nm, respectively. Under this condition, a linear relationship is obtained between procaine hydrochloride and the relative fluorescence intensity. The linear regression equation of the calibration graph is c = 0.022I-0.081, with a linear regression correlative coefficient of 0.9996 and relative standard deviation (RSD) of 3.4%. Influences of pH, foreign ions, kanamycin, gentamycin, benylpencillin, streptomycin and standing for time on the determination of procaine hydrochloride have been examined. The reasons that the relative fluorescence intensity of procaine hydrochloride increases with a rise in pH and with standing for time are discussed. The detection limit of this method is 49 ng.mL-1. The results obtained by the method agreed with those by the official method. The method is simple, and available to be used in the determination of procaine hydrochloride in injection solution.
In order to study duck microsatellites, we constructed a library enriched for (CA)n, (CAG)n, (GCC)n and (TTTC)n. A total of 35 pairs of primers from these microsatellites were developed and used to detect polymorphisms in 31 unrelated Peking ducks. Twenty-eight loci were polymorphic and seven loci were monomorphic. A total of 117 alleles were observed from these polymorphic microsatellite markers, which ranged from 2 to 14 with an average of 4.18 per locus. The frequencies of the 117 alleles ranged from 0.02 to 0.98. The highest heterozygosity (0.97) was observed at the CAUD019 microsatellite locus and the lowest heterozygosity (0.04) at the CAUD008 locus, and 11 loci had heterozygosities greater than 0.50 (46.43%). The polymorphism information content (PIC) of 28 loci ranged from 0.04 to 0.88 with an average of 0.42. All the above markers were used to screen the polymorphism in other bird species. Two markers produced specific monomorphic products with the chicken DNA. Fourteen markers generated specific fragments with the goose DNA: 5 were polymorphic and 9 were monomorphic. But no specific product was detected with the peacock DNA. Based on sequence comparisons of the flanking sequence and repeat, we conclude that 2 chicken loci and 14 goose loci were true homologous loci of the duck loci. The microsatellite markers identified and characterized in the present study will contribute to the genetic map, quantitative traits mapping, and phylogenetic analysis in the duck and goose.