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由硫脲壳聚糖和微量的AgNO3反应得到硫脲壳聚糖Ag+配合物。 通过红外光谱对其结构进行了表征。 研究了壳聚糖、硫脲壳聚糖、硫脲壳聚糖-Ag+配合物及AgNO3对大肠杆菌和金黄葡萄球菌的抑菌活性,并测定了其最低抑菌浓度(MIC)和最低杀菌浓度(MBC)。 结果表明,硫脲壳聚糖-Ag+配合物的抑菌活性强于壳聚糖和硫脲壳聚糖,且其MIC和MBC均为100 mg/L(游离Ag+含量为0.032 mg/L),低于AgNO3的MIC和MBC(均为120 mg/L)。 相似文献
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以水溶性低聚壳聚糖为原料,经水杨醛、香草醛、2,4-二羟基苯甲醛修饰后制得了三种低聚壳聚糖希夫碱钴配合物CS-Sal-Co、CS-Val-Co和CS-Dh-Co,采用FT-IR和ICP对其结构和金属含量进行了分析。首次采用BPR-硫脲催化光度法测定了三种钴配合物的抗.OH活性。结果表明:CS-Sal-Co对.OH的清除效果最好,清除率可达到95.41%;CS-Val-Co对.OH的清除作用较弱,清除率最大为46.77%;CS-Dh-Co对.OH清除率最大为58.50%。探讨了壳聚糖希夫碱钴配合物清除.OH的机理。 相似文献
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用体外抑菌法研究了O-羧甲基壳聚糖镧、O-羧甲基壳聚糖钕配合物对大肠杆菌(E.coli)、金黄色葡萄球菌(St.aureus)、阴沟肠杆菌(E.cloacae)、枯草芽孢杆菌(B.subtilis)、粪肠杆菌(E.faecalis)和肺炎克罗伯杆菌(S.pneumoniae)的抑菌活性。采用紫外光谱研究了两种O-羧甲基壳聚糖稀土配合物与小牛胸腺DNA的相互作用。结果表明:O-羧甲基壳聚糖稀土配合物均有抑菌活性,且O-羧甲基壳聚糖稀土配合物与DNA以静电作用为主,能使DNA双螺旋结构破坏。 相似文献
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We have previously reported the preparation of acetyl and benzoyl phenyl-thiosemicarbazone derivatives of chitosan and their antimicrobial activities. The purpose of this study was to further assess the relationship between chemical structure and antimicrobial activity of chloracetyl phenyl-thiosemicarbazone-chitosan. Ten new chloracetyl phenyl-thiosemicarbazone-chitosans were prepared, and their structures were characterized using FT-IR and elemental analysis. The synthesized compounds were tested against four species of bacteria and four crop-threatening pathogenic fungi. Different molecular weights and concentrations were evaluated. The antifungal activities of the synthesized compounds were related to the positive polarity of the N4 atom and the distribution of the electron atmosphere in the C=S group. All chitosan compounds had inhibitory effects when tested with bacteria. The minimum MIC and MBC with Escherichia coli were 7.03 and 56.25 μg mL?1, respectively. 相似文献
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El-Khawaga Ahmed M. Farrag Ayman A. Elsayed Mohamed A. El-Sayyad Gharieb S. El-Batal Ahmed I. 《Journal of Cluster Science》2021,32(5):1107-1119
Journal of Cluster Science - In this work, iron oxide nanoparticles (Fe3O4 NPs) were modified by chitosan (CS). Fe3O4 NPs were synthesized by co-precipitation method and their antimicrobial... 相似文献
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N. Raman R. Jeyamurugan S. Sudharsan K. Karuppasamy L. Mitu 《Arabian Journal of Chemistry》2013,6(2):235-247
The paper presents the synthesis of complex combinations of Cu(II) and Zn(II) with Schiff base obtained by the condensation reaction of 4-aminoantipyrine with benzaldehyde and 2-amino-3-methyl-butanoicacid. Structural features of synthesized compounds were determined by analytical and spectral techniques. Binding of synthesized complexes with calf thymus DNA (CT DNA) was studied by spectroscopic methods and viscosity measurements. Experimental results indicated the ability of the complexes to form adducts with DNA and to distort the double helix by changing the base stacking. Oxidative DNA cleavage activities of the complexes were studied with supercoiled (SC) pUC19 DNA using gel electrophoresis. The in vitro antimicrobial screening effects of the investigated compounds were monitored by the disk diffusion method. The synthesized Schiff base complexes exhibited higher antimicrobial activity than the respective free Schiff base. The in vitro cytotoxicity of synthesized complexes against Ehrlich ascites carcinoma (EAC) tumor model was investigated using trypan blue dye exclusion assay. The complexes possessed significant cytotoxic activity. 相似文献
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S. Sh. Rashidova R. Yu. Milusheva L. N. Semenova M. Yu. Mukhamedjanova N. L. Voropaeva S. Vasilyeva R. Faizieva I. N. Ruban 《Chromatographia》2004,59(11-12):779-782
Interpolymeric complexes have been obtained from citric pectin and chitosan, the latter synthesized from crab chitin. The composition and structure of complexes obtained from different ratios of the components were studied by IR spectroscopy, rheological investigation of gel structure, and mathematical modelling of system properties. Rheological investigation of the processes involved in the formation of interpolymeric complexes with gel structures from citric pectin and chitosan was conducted in moderately concentrated solutions containing different ratios of the components. It was shown that the toughness of the gel structures was determined by the ratio of the amounts of the heterogeneous polymers. The toughest product (τ=121.4 Pa) was obtained by use of equimolar quantities of pectin and chitosan. With deviation of the composition of the mixture from equimolar the toughness of the gel decreased. It is proposed that the polyelectrolyte pectin–chitosan complex with a network structure is formed at the expense of electrostatic interaction between positively charged amino groups at C-2 of the chitosan pyranose ring and negatively charged carboxyl groups at the C-5 of the pectin pyranose ring. 相似文献
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An ampholytic N-carboxyethyl chitosan (CEC), with various isoelectric points (IPs), was synthesized by grafting acrylic acid on chitosan utilizing Michael's reaction. Compared to native chitosan, CEC has enhanced water solubility and dramatically accelerated enzymatic degradation; the rate of degradation is proportional to the degree of substitution (DS). The results from turbidimetric titration and fluorescence studies revealed that CEC formed complexes with either hyaluronic acid (HA) or bovine serum albumin (BSA) within a certain pH range. The HA/CEC/BSA ternary complexes could be prepared by colloid titration with quantitative yield and BSA entrapment. The rate of BSA release from the complexes was affected by pH, ionic strength, DS of CEC, and the molecular weight (MW) of HA. The endurance of BSA release from the complexes could be extended up to 20 d by formulating them with high-MW HA and CEC with low DS.BSA release profiles from HA/CEC-2/BSA complexes. 相似文献
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Kulkarni AR Kulkarni VH Keshavayya J Hukkeri VI Sung HW 《Macromolecular bioscience》2005,5(6):490-493
Thiazolidinone derivatives (TDCs) were prepared by converting chitosan into chitosan's Schiff's bases (CSBs), followed by treatment with mercaptoacetic acid. Both CSBs and TDCs were tested for antimicrobial activity against four different bacteria. All TDCs showed comparatively better anti-microbial activity without much affecting basic physical properties of chitosan such as film-forming capacity, tensile strength, etc. This indicates that chitosan derivatives with a thiazolidinone moiety might be a better material for wound dressing. 相似文献
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In this study, benzenesulfonicacid‐1‐methylhydrazide (bsmh) derivatives such as 2‐hydroxy‐1‐naphtaldehydebenzenesulfonylhydrazone (Hnafbsmh) and its Ni(II), Pd(II), Pt(II), Cu(II), Co(II) complexes were synthesized. The structures of these complexes were investigated using elemental analyses (FT‐IR, LC‐MS, UV‐VIS), magnetic susceptibility and conductivity measurement techniques. The complexes were found to have general compositions [ML2]. All the synthesized complexes were evaluated in vitro as antimicrobial agents against representative strains of six gram‐positive and four gram‐negative bacteria and as an antifungal agent by disc diffusion methods. All the bacteria and fungi studied were screened against some commercial antibiotics to compare them with our chemical's zone diameters. 相似文献
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Biological contour,molecular docking and antiproliferative studies of DNA targeted histidine based transition metal(II) complexes: Invention and its depiction 下载免费PDF全文
A novel series of histidine derived transition metal complexes were synthesized and characterized by multispectral techniques such as UV‐Vis., FT IR, EPR, NMR, ESI‐mass analysis and other physico‐chemical methods like elemental analysis, molar conductivity, magnetic susceptibility. The synthesized compounds were attempted for their biological prospective. The biological studies involved are DNA interaction (binding and damage), antimicrobial, antioxidant, antiproliferative and molecular docking. DNA interaction studies were carried out with the help of UV‐Vis absorption titration, viscosity measurement and cyclic voltammetric techniques which revealed that the synthesized compounds could interact with CT‐DNA through intercalative binding mode. A gel electrophoresis assay demonstrated the ability of complexes to cleave the supercoiled pUC18 DNA. The antioxidant property shows that the metal complexes have preferable ability to scavenge hydroxyl radical than the ligand. Moreover, the antimicrobial assay indicates that these complexes are good antimicrobial agents against various pathogens. Furthermore, the in vitro antiproliferative activities of the complexes were examined on HeLa, Hep G2 and NIH 3 T3 cell lines using an MTT assay. The morphological changes were investigated using Hoechst 33258 staining apoptosis assay. In addition, molecular docking studies were executed to considerate the nature of binding of the synthesized complexes with protein and DNA. 相似文献
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Natarajan Raman Ramaraj Jeyamurugan Mariyyappan Subbulakshmi Raja Boominathan Chithu Ramakrishnan Yuvarajan 《Chemical Papers》2010,64(3):318-328
A novel series of Co(II), Ni(II), Cu(II), Zn(II), and VO(IV) complexes has been synthesized from the Schiff base derived from
4-[(3,4-dimethoxybenzylidene)amino]-1,5-dimethyl-2-phenyl-1,2-dihydropyrazol-3-one and 1,2-diaminobenzene. Structural features
were determined by analytical and spectral techniques. Binding of synthesized complexes with calf thymus DNA (CT DNA) was
studied by spectroscopic methods and viscosity measurements. Experimental results indicate that the complexes are able to
form adducts with DNA and to distort the double helix by changing the base stacking. Lower DNA affinity of the VO(IV) complex
is caused by the change of coordination geometry by the vanadyl ion resulting in a somewhat unfavorable configuration for
the DNA binding. Oxidative DNA cleavage activities of the complexes were studied with supercoiled (SC) pUC19 DNA using gel
electrophoresis; the mechanism studies revealed that the hydroxyl radical is likely to be the reactive species responsible
for the cleavage of pUC19 DNA by the synthesized complexes. The in vitro antimicrobial screening effects of the investigated
compounds were monitored by the disc diffusion method. The synthesized Schiff base complexes exhibit higher antimicrobial
activity than the respective free Schiff base. 相似文献