绿脓杆菌Pseudomonas aeruginosa BTE-1直接电催化特征

本文研究厌氧条件下产电绿脓杆菌P. aeruginosa BTE-1的电化学催化特征。研究结果表明,P. aeruginosa BTE-1菌株在厌氧条件下,不能分泌可充当电子介体的绿脓菌素,但可通过在电极表面形成生物膜呈现了直接电催化性能。P. aeruginosa BTE-1在电极表面形成生物膜与其在特定电极电位下向电极传递电子的过程直接相关,适宜的电位为+0.2 V (vs. SCE),电位过高可能会损害P. aeruginosa BTE-1细胞。室温范围内升高温度可增强P. aeruginosa BTE-1生物膜电催化活性,但过高的温度(>60℃)会抑制生物膜电催化活性。循环伏安曲线显示,在厌氧条件下形成的P. aeruginosa BTE-1生物膜,具有与典型产电菌株G. sulfurreducens相近的氧化还原电位(-0.4 V~ -0.2 V vs. SCE)。P. aeruginosa BTE-1生物膜可电催化酵母抽取物和葡萄糖,但不能电催化醋酸盐。     

基于芳基糠醛功能化巴比妥酸衍生物识别和分离Hg~(2+)/Fe~(3+)的新型荧光传感器（英文）

合成了一种新型的基于5-(3-硝基苯基)-呋喃-2-甲醛功能化的巴比妥酸衍生物传感器QS.通过~1H NMR, 13C NMR, MS等方法对QS进行了表征. QS的荧光光谱结果表明QS的二甲亚砜(DMSO)溶液在498 nm有最大荧光发射,在365 nm紫外灯下照射发出绿色荧光. QS对Hg~(2+)和Fe~(3+)的水溶液有不同的荧光检测能力, Hg~(2+)能使探针QS的荧光增强为橙色,Fe~(3+)使其荧光猝灭,实现了实时检测.传感器QS对Hg~(2+)和Fe~(3+)的荧光检测限分别为3.25×10~(-8)和4.0×10~(-8) mol·L~(-1).根据Job曲线和质谱研究得到QS与汞离子和铁离子化学计量比均为1∶1,提出了QS与Hg~(2+)和Fe~(3+)的可能结合模式.加入H 2P O4-能使含有Fe~(3+)的QS溶液(QS-Fe)荧光恢复,可用于Fe~(3+)的循环检测.此外,固体QS可从水溶液中吸附Hg~(2+)和Fe~(3+)(吸附率分别为92.0%和91.8%),具有较好的吸附能力.     

8-羟基喹啉-5-磺酸构筑的有机-无机配位化合物的合成、结构和性质研究

在溶剂热条件下,以8-羟基喹啉-5-磺酸为配体,合成了两个新的有机-无机配位化合物Mn（QS）（H2O）（1）和Co（QS）（H2O）2（2）（H2QS=8-hydroxylquinoline-5-sulfonic acid）,并且对他们进行了单晶X-射线解析.其中化合物1是一个具有金红石拓扑的三维开放骨架结构,化合物2是一个三维超分子结构.我们对这些化合物进行了粉末X射线,红外光谱,差热热重,荧光光谱和磁学性质的研究.     

The toxicity of Cu~(2+) to Microcystis aeruginosa using dielectric spectroscopy

Dielectric spectroscopy(DS) was utilized to investigate the toxicity of the Cu2+ solution to Microcystis aeruginosa.It was found that 0.04 mM Cu2+ had no effect on dielectric increment,whereas the Cu2+ concentrations above 0.1 mM decreased the value of Δε/Δε intact.The toxic effect of Cu2+ on M.aeruginosa cells was time-dependent and concentration-dependent.There was a threshold concentration between 0.04 mM and 0.1 mM,which affected the cell membrane,suggesting that Cu2+ at the concentrations higher than 0...     

Discovery of synergistic activity of fluoroquinolones in combination with antimicrobial peptides against clinical polymyxin-resistant Pseudomonas aeruginosa DK2

Polymyxin B(PB),as the last-line of defense against multidrug-resistant Gram-negative bacteria,has caused resistance to P.aeruginosa recently.Fortunately,synergistic treatment could preserve the last class of antibiotics and reduce the emergency of drug resistance.Here,we performed a screen of 970 approved drugs synergized with PB against the P.aeruginosa DK2,which is severely resistant to PB,MIC=512μg/mL.Encouragingly,we found fluoroquinolones could synergy with PB and achieved an obvious reduction in MIC of PB below the clinical susceptible breakpoint(2 μg/mL).Especially,gemifloxacin achieved the highest synergistic effect with PB,leading to a 4096-fold MIC reduction(reduced from512 μg/mL to 0.125 μg/mL).Furthermore,synergistic effect was also observed in the combination of gemifloxacin and colistin.Finally,outer membrane permeabilization assay showed that gemifloxacin could increase the permeability of bacterial cell membranes for P.aeruginosa which partly explained the synergy mechanism.These results indicate that fluoroquinolones represent attractive synergists to address the emerging threat of polymyxin-resistant infections.     

An eco-friendly water mediated synthesis of 1,2,3-triazolyl-2- aminopyrimidine hybrids as highly potent anti-bacterial agents

An elegant and efficient synthesis of novel 1,2,3-triazole fused 2-aminopyrimidine hybrids has been accomplished for the first time in the green solvent viz. water. The hybrid molecules exhibit significant anti-bacterial activity when screened against three human pathogens viz. Staphylococcus aureus, Pseudomonas aeruginosa and Klebsiella pneumoniae. In comparison to the commercially marketed drug tetracycline, some of them are equally potent and a few are more potent.     

咪唑取代的双羟基季铵盐的合成及抗菌性质研究

将咪唑基团与N-甲基二乙醇胺进行季铵化反应,经过重结晶纯化得到2-(2-羟乙基)-甲基-(1-甲基-1H-咪唑-2-亚甲基)氯化铵(QAS-1),以傅立叶变换红外光谱(FT-IR)、核磁共振(NMR)和飞行时间质谱(TOF-MS)等进行结构表征。并采用纸片法和振荡培养法初步研究了QAS-1对金黄色葡萄球菌(S.aureus)、甲型链球菌(α-H-tococcus)、大肠杆菌(E.coli)、绿脓杆菌(P.aeruginosa)等菌种的抗菌性能。结果显示,季铵盐QAS-1对这4种菌均显示较好的抗菌活性,特别是对革兰氏阴性菌(E.coli,P.aeruginosa)的杀菌效果更加显著,且优于阳性药(葡萄糖酸氯己定)。     

Study on the synthesis and antimicrobial activity of novel cationic porphyrins

A novel series of quaternary ammonium cationic derivatives based on tetrapyridyl-porphyrin was synthesized.All the compounds were evaluated for their in vitro antibacterial activities against S.aureus,E.coli and P.aeruginosa,and antifungal activities against C.albicans,where microorganisms were exposed and unexposed to the irradiation.The results revealed that some of these compounds,especially,3a and 4a displayed satisfactory antibacterial activity against Gram-positive bacteria S.aureus and moderate an...     

Novel dihydropyrazole derivatives linked with multi（hetero）aromatic ring： Synthesis and antibacterial activity

Eight novel heterocycle-substituted dihydropyrazole derivatives were synthesized and characterized by ESI-MS,~1H NMR and ~(13)C NMR.All of the compounds have been screened for their antibacterial potential in vitro against Bacillus subtilis, Staphylococcus aureus,Escherichia coli and Pseudomonas aeruginosa.The results show that compounds 9b,9g and 9h displayed significant activity with MIC values in the range of 0.39-1.562μg/mL against B.subtilis.     

Antibacterial behaviour of quaternized poly(vinyl chloride)-g-poly(4-vinyl pyridine) graft copolymers

Amphiphilic graft copolymers consisting of poly(vinyl chloride)(PVC) main chains and poly(4-vinyl pyridine)(P4VP) side chains were synthesized via atom transfer radical polymerization(ATRP) using direct initiation of chlorine atoms. The successful synthesis of PVC-g-P4 VP graft copolymers was confirmed by Fourier transform infrared spectroscopy(FTIR) and proton nuclear magnetic resonance(1H-NMR). Transmission electron microscope(TEM) and small angle X-ray scattering(SAXS) analysis showed that PVC-g-P4 VP exhibited microphase-separated, ordered structure with 37.6 nm of domain spacing, which was not observed in neat PVC. For antibacterial applications, the tertiary nitrogen atoms of PVC-gP4 VP was quaternized using 1-bromohexane, as confirmed by FTIR measurements. Bacteria including Escherichia coli(E. coli), Staphylococcus aureus(S. aureus), Bacillus cereus(B. cereus), and Pseudomonas aeruginosa(P. aeruginosa) were completely killed in 24 h on the quaternized PVC-g-P4VP(46% grafting) surface, indicating its excellent antibacterial behavior while it showed to be cytotoxic to mammalian cell.     

Multicomponent domino process for the synthesis of some novel 5-(arylidene)-3-((1-aryl-1H-1,2,3-triazol-4-yl)methyl)-thiazolidine-2,4-diones using PEG-400 as an efficient reaction medium and their antimicrobial evaluation

A series of novel thiazolidinedione-triazole hybrids were synthesized by one pot reaction between thiazolidine-2.4-dione,substituted aryl aldehydes,piopargyl bromide and substituted aryl azides using piperidine,CuSO_4· 5H_2O and sodium ascorbate as catalysts in PEG-400 as a highly efficient and green media.These thiazolidinedione-triazole hybrids were subjected to in vitro antibacterial activity against four strains namely.Staphylococcus aureus.Bacillus subtilis,Escherichia coli,Pseudomonas aeruginosa and antifungal activity against two fungal strains namely,Aspergillus niger and Aspergillus flavus.     

气质联用技术检测海绵共栖细菌中N-酰基高丝氨酸内酯类信号分子

近年来,许多学者提出微生物的化学防御即活性物质的代谢是由群体感应(Quorum sensing,QS)来调控的假说~([1]).N-酰基-高丝氨酸内酯(AHLs)类化合物是革兰氏阴性菌群体感应系统中最典型的一类信号分子.     

固溶体Ce1-xEuxO2-δ的151Eu Mssbauer谱和电性能研究

利用溶胶-凝胶方法在800 ℃灼烧10 h后, 合成了固溶体Ce1-xEuxO2-δ(x=0.05～0.5), 晶粒平均尺寸为60 nm左右, XRD分析表明固溶体的结构为单相立方萤石结构. M(o)ssbauer谱测试表明固溶体Ce1-xEuxO2-δ中Eu离子价态为+3价, 同质异能移IS值随掺杂量x增加而增大. Eu3+的四极劈裂QS值小于零, 表明Eu3+周围的晶体场是非对称的, QS的绝对值随掺杂量x增加而增大, 说明随掺杂量x增加, 晶体场对称性越差. 阻抗谱测试表明通过掺杂使固溶体Ce1-xEuxO2-δ的导电率得到很大提高, 电导率在x=0.2时达到最大值σ800 ℃=1.28×10-2 S·cm-1, 电导活化能达到最小值为Ea=0.72 eV.     

二茂铁基查耳酮系化合物的Mossbauer谱研究

本文合成了两个二茂铁基查耳酮系化合物3b-3eC5H5FeC5H4CO(CH=CH)nC6H5(n=1,2,3,4)和6a-6cC5H5FeC5H4(CH=CH)nCOC6H5(n=0,1,2)。为了研究这类三岔共轭体系的结构效应,我们用Mossbauer效应为探针, 研究了二茂铁基Fe核周围的电子云分布情况。并用同系因子(1/a)^1^/^N考查了Mossbauer谱参数QS和IS的同系递变规律。结果表明3系中的茂铁基只起代基作用; 6系中的茂铁基则为端基。3系中共轭链的增长引起QS值的减小, 可能是诱导效应所致, 并讨论了取代基的吸电子效应和茂环与铁核间距离对IS和QS值减小的影响。     

Synthesis and antibacterial activity of ethyl 2-amino-6-methyl-5-oxo- 4-aryl-5,6-dihydro-4H-pyrano[3,2-c]quinoline-3-carboxylate

The three-component reaction of 4-hydroxy-1-methyl-2(1H)-quinolinone, aromatic aldehydes and ethyl cyanoacetate was carried out in the presence of a catalytic amount of 4-dimethyl aminopyridine(DMAP) in aqueous ethanol. The reactions result in the formation of pyranoquinoline derivatives in excellent yields. Antibacterial activity has been evaluated against Gram positive and Gram negative bacteria for some of the synthesized compounds. The results indicated that these compounds are moderately effective against bacterial growth and their effectiveness is highest against Pseudomonas aeruginosa.     

Inhibitory effects of the extracts with different solvents from three compositae plants on cyanobacterium Microcystis aeruginosas

The algicidal activity of the terrestrial plants is a novel and promising means for alga control of eutrophic waters.In this study,three compositae plants — Artemisia annua(A.annua),Conyza canadensis(C.canadensis),and Erigeron annuus(E.annuus) were selected and antialgal activity of petroleum ether(PE),ethyl acetate(EA) and ethanol extracts of these plants on blue algae Microcystis aeruginosa was investigated.The result shows the EA extracts of these plants present the stronger inhibitory effects.The result...     

表面活性剂存在下,7-碘-8-羟基喹啉-5-磺酸与 Zn(Ⅱ)荧光配合反应的研究

由于CTMAB或Zeph的引入,Zn(Ⅱ)与7-碘-8-羟基喹啉-5-磺酸(7-I-H_2QS)荧光配合反应被明显地增敏了,荧光强度净增三倍多。主要原因是荧光量子效率的增大。λEX_(max),λEM_(max)和适宜酸度范围由二元体系的373nm,545nm,和pH6.8—7.4,分别移至396nm,526nm和pH3.8—4.8(CTMAB)或pH5.8—6.6(Zeph)。采用7-I-H_2QS作为光试剂,由于分子内重原子效应,使荧光强度和量子效率均比相应的H_2QS体系低,但适宜酸度范围明显地酸移,空白值很低。利用等吸点激发-校正发射谱积分面积比法测定了各体系的荧光量子效率。     

ACTA PHYSICO-CHIMICA SINICA Vol.17 No.1-12 2001 INDEXCLASSIFIED SUBJECT INDEX

I. THERMODYNAMICS, THERMOCHEMISTRY ANDSOLUTION CHEMISTRYReaction Mechanism between Ciprofloxacin Hydrochloride and Bovine Serum Albumin.....Shang ZC Yi PG Yu QS Lin RS(1)48Cluster in Dehydrogenation of Dodecane to Internal Dodecane in Supercritical Phase ..... Wei W Chan J Sun YH Zhong B(1)59DSC Study on the Thermal Hysteresis Activity of Plant Antifreeze Proteins ................. Zhou XL Chen TT Wang BH et al. (1)66Investigation of Thermal Decompositi…     

表面活性剂对金属荧光反应的增敏作用

研究了各种类型的表面活性剂对铪-栎精、锆-栎精、锡-桑色素、镁-8-羟基喹啉-5-磺酸(镁-H_QS)、锌-H_2QS、镉-H_2QS、铽-EDTA-磺基水杨酸体系荧光光谱的影响.结果表明:在适当的表面活性剂存在下,各种配合物的荧光强度均大大增强.确定了在有表面活性剂参与下三元配合物的最佳形成条件;以荧光法测定了这些荧光配合物的组成.用相对法测定了有表面活性剂和没有表面活性剂存在时荧光配合物的量子效率,并计算了在激发波长下各自的摩尔吸光系数.发现在有表面活性剂存在时,由于生成了有固定组成的三元离子缔合物,荧光配合物的量子效率和摩尔吸光系数都有不同程度的提高,从而大大增强了它们的荧光强度.讨论了表面活性剂胶束的作用以及表面活性剂的分子结构对荧光反应的影响.指出只有那些分子中带电荷基团与共轭大π键不相邻的表面活性剂才能对荧光反应起增敏作用.利用表面活性剂的增敏作用有可能建立一些高灵敏度的金属荧光分析法.     

二茂铁基查耳酮系化合物的Mssbauer谱研究

本文合成了两个二茂铁基查耳酮系化合物3b—3eC_5H_5FeC_5H_4CO(CH=CH)_nC_6H_5(n=1,2,3,4)和6a—6cC_5H_5FeC_5H_4(CH=CH)_nCOC_6H_5(n=0,1,2)。为了研究这类三岔共轭体系的结构效应,我们用Mssbauer效应作为探针,研究了茂铁基Fe核周围的电子云分布情况,并用同系因子(1/α)~(2/N)考查了Mossbauer谱参数QS和IS的同系递变规律,结果表明3系中的茂铁基只起代基作用;6系中的茂铁基则为端基,3系中共轭链的增长引起QS值的减小,可能是诱导效应所致,并讨论了取代基的吸电子效应和茂环与铁核间距离对IS和QS值减小的影响。