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排序方式: 共有128条查询结果,搜索用时 187 毫秒
121.
《Journal of Coordination Chemistry》2012,65(15):1263-1269
The interactions of cephalexin (Hcepha) with transition and d10 metal ions have been investigated. The complexes [M(cepha)Cl]nH2O [M?=?Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II)] were characterized by physicochemical and spectroscopic methods. The IR and 1H NMR spectra of the complexes suggest that cephalexin behaves as a monoanionic tridentate ligand. In vitro antibacterial activities of Hcepha and the complexes were tested. 相似文献
122.
Philip J. Parsons Jonathan Board Davide Faggiani Peter B. Hitchcock Lewis Preece Alexander J. Waters 《Tetrahedron》2010,66(33):6526-6075
A new and highly efficient route for the construction of a model for the synthesis of lactonamycin 1 is reported. The chemistry has been utilised for the synthesis of heterocyclic rings, and new reactions for the synthesis of dienes and alkynes are reported. 相似文献
123.
The synthesis of racemic cedarmycin B,an antibiotic from Streptomyces sp.TP-A0456 was achieved firstly fromγ- butyrolactone.The key step was a Barbier-type addition of 3-bromomethyl-5H-furan-2-one to formaldehyde mediated by zinc, which afforded the soleγ-addition product 4-hydroxymethyl-3-methylene-dihydrofuran-2-one.The final compound was confirmed by ~1H NMR,~(13)C NMR and HRMS. 相似文献
124.
125.
荧光光度法测定抗生素氧氟沙星 总被引:11,自引:2,他引:9
本文报道了采用荧光分光光度法测定喹喏酮类抗生素氧氟沙星,该方法有较高的灵敏度,在氧氟沙星浓度为0.500ppm至25.0ppm间,荧光强度与浓度有良好的线性关系,线性相关系数为0.9999,回收率为99.0%测定结果与紫外分光光度法测量结构无显著性差异。 相似文献
126.
Afaq Ullah KHAN Faheem SHAH Rafaqat Ali KHAN Bushra ISMAIL Asad Mohammad KHAN Haji MUHAMMAD 《Turkish Journal of Chemistry》2021,45(4):1201
Every year, tuberculosis affects the lungs of millions of people and rifampicin is the commonly used medicine for its treatment due to its antibiotic nature. The frequent use of rifampicin may lead to its increased concentration in the water resources. This research work is focused on the cloud point extraction (CPE) procedure for the preconcentration of rifampicin prior to its determination in water. The UV/vis spectrophotometric method was adapted for the measurement of rifampicin content after the phase separation. Triton-X 100 was used as the nonionic surfactant which contains hydrophilic polyethylene chain feasible for the extraction of analyte. Various analytical parameters that can affect the extraction efficacy were optimized to achieve linearity of the proposed method in the concentration range of 3.54–81.41 mgL–1. The Limit of detection and quantification were 1.261 and 4.212 mgL–1, respectively. The Preconcentration factor was 40 with relative standard deviation (%RSD) of 2.504%. The standard addition methodology was adopted for the validation of this procedure and effectively applied for the determination of rifampicin in real wastewater samples. 相似文献
127.
A luminescent lanthanide-organic framework [Eu2(adip)(H2adip)(DMF)2]·CH3OH ( 1 ) was synthesized by a solvothermal method using anthracene-based ligand 5,5’-(anthracene-9,10-diyl)diisophthalic acid (H4adip). 1 possesses a 3D coordination framework, which could be rationalized as a 4,8-connected 2-nodal (416612)(4462) topological network. 1 shows an excellent linear increase in fluorescence intensity as the pH value rises from 4.8 to 7.1. Particularly, the fluorescence enhancement percentage reaches 588% for each increase of pH value, which is the highest value recorded for fluorescence pH sensing materials, promoting the sensitivity of pH detection within the physiological pH range. In addition, 1 can also specifically recognize carbon disulfide biomarkers 2-thiothiazolidine-4-carboxylic acid (TTCA) and antibiotic aztreonam (ATM) by fluorescence quenching, with the KSV values of 1.02 × 105 L·mol–1 (0—10 μmol·L–1) and 4.67 × 105 L·mol–1 (0—50 μmol·L–1), the limit of detection (LOD) of 86 nmol·L–1 and 19 nmol·L–1, respectively. Among only a few cases reported, the detection sensitivities of 1 for both TTCA and ATM are the highest. The sensing mechanisms of pH, TTCA, and ATM are also discussed in detail. 相似文献
128.
Dr. Kai Yang Fei Xu Longji Zhu Dr. Hongzhe Li Prof. Qian Sun Prof. Aixin Yan Prof. Bin Ren Prof. Yong-Guan Zhu Prof. Li Cui 《Angewandte Chemie (International ed. in English)》2023,62(14):e202217412
Understanding evolution of antibiotic resistance is vital for containing its global spread. Yet our ability to in situ track highly heterogeneous and dynamic evolution is very limited. Here, we present a new single-cell approach integrating D2O-labeled Raman spectroscopy, advanced multivariate analysis, and genotypic profiling to in situ track physiological evolution trajectory toward resistance. Physiological diversification of individual cells from isogenic population with cyclic ampicillin treatment is captured. Advanced multivariate analysis of spectral changes classifies all individual cells into four subsets of sensitive, intrinsic tolerant, evolved tolerant and resistant. Remarkably, their dynamic shifts with evolution are depicted and spectral markers of each state are identified. Genotypic analysis validates the phenotypic shift and provides insights into the underlying genetic basis. The new platform advances rapid phenotyping resistance evolution and guides evolution control. 相似文献