Abstract A new method was described for simultaneous determination of ciprofloxacin (CIP), ofloxacin (OFL) and norfloxacin (NOR) by capillary electrophoresis with a diode array detector at 280 nm. The separation conditions were investigated and optimized. A new medium, 30 mM sodium tetraborate buffer solution and 22 mM sodium dodecyl sulphate containing 5% (v/v) methanol (pH 8.7), was developed for the complete separation of the three quinolones. The excipients do not affect to separation and analysis. Calibration curves between peak area and concentration in the range 10-1000 mg/L for each compound have good linearity with a correlation coefficient (r) of greater than 0.999, and the detection limit£¨s/n£© was 7.90 mg/L for CIP£¬7.92 mg/L for OFL and 7.56 mg/L for NOR. This method has been successfully applied for simultaneous determination of CIP, OFL and NOR in the pharmaceutical preparations with rapid, accurate, and simple characteristics.
Keywords Capillary electrophoresis; Ciprofloxacin; Ofloxacin; …
Author: AngelStgerman
Research progress of CTG repeats in structural biology
Research progress of CTG repeats in structural biology
Hu Haiming, Xue Yonglai, Feng Xizeng (The Key Laboratory of Bioactive Materials Ministry of Education, China, College of Life Science, Nankai University, Tianjin, 300071)
Abstract Myotonic dystrophy type1(MD) is an autosomal dominant neuromuscular disease, its heredity mechanism is the expansions of CTG repeats in the 3′-untranslated region of the myotonic dystrophy protein kinase(DMPK). This paper introduces the structure features of CTG biochemical feature, expansion mechanism, factors that influence its expansion, and the relationship between expansion and MD.
Keywords Myotonic dystrophy, trinucleotide repeats CTG, expansion, structure, S-DNA
Advances in Structural Biology Research of CTG Repeat Sequence
Hu Haiming, Xue Yonglai, Feng Xizeng
(Key Laboratory of Bioactive Materials, Ministry of Education, School of Life Sciences, Nankai University, Tianjin 300071)
Abstract Myotonic dystrophy (MD) is an autosomal dominant neuromuscular disease. Its genetic mechanism is caused by abnormal expansion of CTG repeat sequence located in the …
Synthesis and characterization of copper(II) complexes with heterocyclic aromatic selenium compounds
Sui Chaoxia1, Yang Fang1,2, Zheng Wenjie1,2, Bai Yan1
(1 Department of Chemistry, Jinan University; 2 Research Center of Hydrobiology, Jinan University, 510632, China)
Received Dec. 24, 2005; Supported by the National Natural Science Foundation of China (No.20271022) and Guangdong Natural Science Foundation (No.010369)
Abstract A series of complexes CuL2Cl2 (L= NS, MB, BS) were synthesized, based on the liquid-phase reaction of piazselenole(NS), 5-methyl- piazselenole(MB), 4,5-benzopiazselenole(BS), which acted as ligands and Cu2+ as cation. The physicochemical properties of the complexes were determined by ICP-AES, EA, FT-IR analysis, UV-Vis, XRD, FS etc. The coordination mechanism between ligands and Cu2+ was also discussed.
Keywords heterocyclic aromatic selenium compounds, copper complexes, synthesis and characterization
Selenium is the trace element controlled by gene in human body[1]. Heterocyclic aromatic selenium compounds (Piaselenole, Pis) are a sort of important compounds derived by …
Optical emission spectrum online diagnoses for CH4+H2 discharge plasma system at atmospheric pressure
Ren Longliang, Cui Jinhua#
( Department of Physics, Science College, Tianjin University, Tianjin 300072; # Department of Chemistry, Liaoning Normal University, Dalian 116021 )
Abstract Optical emission spectra in CH4+H2 discharge plasma system with high voltage and high frequency pulse at atmospheric pressure was preliminarily diagnosed in order to optimize discharge condition for CH4 coupling under plasmas. It was shown that CH, CH2 and C2 radicals were main species in the system. Spectral intensity of C2 swan band at 50 W of supplied power was higher than that at 72 W. Cathode sputtering and black-body radiation increased with the increase of the supplied power for the discharges.
Keywords Plasma, methane coupling, optical emission spectrum diagnoses
Spectral lines abound in optical spectrogram of plasma emission, from visible light to ultraviolet radiation and even to X-rays. The emission is caused by motion of numerous …
Study of amino acids correlation in proteins and application in structural analysis
Du Qishi a*, Wang Shuqing a, Wei Dongqing a, Li Aixiua,b
(aInstitute of Bioinformatics and Drug Discovery, Tianjin Normal University; bMedical College of Chinese People’s Armed Police Forces, Tianjin, 300162)
Abstract In this research we calculate the correlation coefficients and analyze the correlation relationship among 20 amino acids in 4 type proteins (a, b, a/b, and a+b), total 204 proteins. Our research shows that amino acid correlations can be divided into strong positive correlation, strong negative correlation, weak correlation, and no-correlation. The correlation relationships of amino acids in 4 type proteins are quite different, and represent the protein’s structure characters. We analyze the relationship between amino acid correlation and the structure of proteins and give explanation for the physicochemical origins of amino acid correlations.
Keywords Amino acids; Protein structure; Bioinformatics; Chemometrics
Amino Acid Correlation in Proteins and Its Application in Structural Analysis
Du …
Preparation and characterization of (C4H9NH3)2CuX4 (X=Cl, Br)
Liu Hanxing, Wang Xian, Hu Weida , Guo Liling , Ouyang Shixi
(State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China)
Received Mar. 8, 2004; Supported by Key Program of the National Nature Science Foundation of China (No.90206047)
Abstract Organic-inorganic layered perovskite-type compounds (C4H9NH3)2CuX4 (X=Cl, Br) were prepared from solutions in an air atmosphere. X-ray diffraction, Scanning electron microscopy (SEM), FTIR spectroscopy and thermal analysis (TG and DSC) were used to characterize the obtained powders. From the SEM pictures, both of (C4H9NH3)2CuCl4 and (C4H9NH3)2CuBr4 took on obvious sheet-like microstructure, as well as their XRD profiles demonstrated the crystals growth were highly oriented. The FTIR spectrum showed that the characteristic peaks of (C4…
Determination methods for total carbon concentration in water samples
Wei Yanlin, Lin Jinming
(Research Center for Eco-Environmental Science, Chinese Academy of Science, P.O. Box 2871,
Beijing 100085, China)
Received Nov. 2, 2003; The Project Sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry.
Abstract In this paper, determination methods of total carbon concentration (TC), including total inorganic carbon (TIC) and total organic carbon (TOC) were summarized. TIC determination in natural water samples is essentially vital, especially in sea water samples, for studying the present and future global CO2 air-sea flux. Flow injection analysis (FIA) coupled with a gas diffusion unit (GDU) is proved to be simple, sensitive, rapid and easy to operate for TIC determination. TOC determination is one of the most important works for acquiring knowledge about water and wastewater quality. TOC analysis procedures include two steps, firstly converting the component of organic matter to CO2 and then detecting …
Determination of Tanshinone IIA in two kinds of Chinese traditional patent medicines by HPLC
Abstract A HPLC method for the determination of Tanshinone IIA in the Dan Qi Pian and Tong Mai Chongji was established. The sample was dissolved in methanol and extracted by ultrasound, then chromatographed on LUNA-C18 column with mobile phase of methanol-water (84:16). The flow rate was set at 0.8mL/min and the detection wavelenghth was of 270nm. This HPLC method is simple, rapid and accurate, it can be used to determine Tanshinone IIA in the Dan Qi Pian and Tong Mai Chongji quantitatively .
Keywords Tanshinone IIA, Dan Qi Pian, Tong Mai Chongji, HPLC
Dan Qi Pian and Tong Mai Chongji are general Chinese traditional patent medicines. Although they are edited in the eighth volume(1993) of Medicine Standards published by the Ministry of Health of the People‘s Republic of China, there was not any determination method for their effective components. Hence it was difficult to examine the quality …
Microcalorimetric investigation of thermochemical characteristics of the growth metabolism of Tetrahymena pyriformis
Liu Yi1, 2 Sun Dayuan1 Yu Yuhe2 Qu Songsheng1 Shen Yunfen2
(1Department of Chemistry, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China; 2Laboratry of Protozoology, Institute of Hydrobiology, Chinese Academy of Science, Wuhan 430072, China)
Received Sep.6, 2001; Supported by the National Natural Science Foundation of China (NSFC), and Young Mainstay Teachers’ Program of Chinese Educational Ministry.
Abstract The heat output of the growth metabolism of Tetrahymena pyriformis has been determined by using a LKB-2277 BioActivity Monitor at 25°C. From the thermogenic curves, it can be established that thermokinetic equation of their growth metabolism is Pt = Pt=0 exp(km t), dP / dt = km P1 ,with the order of growth metabolism n = 1. The experimental results indicate that the relationship between the metabolic power (P) and …