Lysozyme(EC3.2.1.17)plays an important role in the immune response;as a nonspecific immune factor,it can resist causative agents.Lysozyme can be divided into c-type and g-type in fish.In a previous study,through genom...Lysozyme(EC3.2.1.17)plays an important role in the immune response;as a nonspecific immune factor,it can resist causative agents.Lysozyme can be divided into c-type and g-type in fish.In a previous study,through genome-wide association analysis,the g-type lysozyme gene,which is named NaLyg in yellow drum(Nibea albiflora),was found to be a key candidate gene for disease resistance in response to Vibrio harveyi infection.The cDNA of NaLyg was 1025 bp,including four exons and three introns,and its open reading frame(ORF)had a full-length of 582 bp,encoding 193 amino acids.NaLyg was found to be conserved during evolution through bioinformatic analyses.The NaLyg protein possessed a sugar binding domain and three catalytic sites,including Glu71,Asp84 and Asp101.Quantitative qRT-PCR results confirmed that NaLyg gene mRNA was visibly increased after V.harveyi infection.The NaLyg protein purified by prokaryotic expression killed some gram-negative bacterial pathogens by inducing cell wall destruction,including V.harveyi,Aeromonas hydrophila and Edwardsiella tarda.Moreover,the NaLyg protein killed two gram-positive bacteria,Bacillus subtilis and Staphylococcus aureus.Taken together,the experimental results suggested that the NaLyg protein of N.albiflora played an important role in fighting bacterial infections.展开更多
Carboxymethyl starch/silver oxide nanocomposites(CMS-Ag_(2)O NCs)were successfully fabricated by modifying carboxymethyl starch(CMS)with Ag_(2)O obtained from an aqueous AgNO_(3)solution as silver source.Ag_(2)O nanop...Carboxymethyl starch/silver oxide nanocomposites(CMS-Ag_(2)O NCs)were successfully fabricated by modifying carboxymethyl starch(CMS)with Ag_(2)O obtained from an aqueous AgNO_(3)solution as silver source.Ag_(2)O nanoparticles(NPs)formed on the surface of CMS by ion exchange.Based on SEM images,the diameters of Ag_(2)O NPs were determined to be between 50 and 100 nm.From the XRD spectra of CMS-Ag_(2)O NCs,the new diffraction peaks appeared at 33.88°and 38.08°,which were attributed to the Ag_(2)O NPs.According to the XPS analysis,Ag 3d_(5/2)and Ag 3d_(3/2)peaks in CMS-Ag_(2)O NCs were fitted into two main peaks centered at 367.6 eV and 373.6 eV,which were attributed to Ag^(+).The antibacterial efficiencies of CMS-Ag_(2)O NCs against Escherichia coli,Staphylococcus aureus,Pseudoalteromonas tetraodonis,Micrococcus luteus,and Shewanella putrefaciens were determined to be 99.6%,99.7%,99.4%,99.5%,and 99.6%,respectively.The antibacterial efficiencies of CMS-Ag_(2)O NCs against the bacterial species were all greater than 99%.Therefore,these results indicated that CMS-Ag_(2)O NCs was highly effective as a bactericidal agent against multiple bacterial species.CMS-Ag_(2)O NCs can be further applied to antifouling coating.展开更多
Antibacterial activity of zinc oxide nanoparticles(Zn O-NPs) has received significant interest worldwide particularly by the implementation of nanotechnology to synthesize particles in the nanometer region. Many micro...Antibacterial activity of zinc oxide nanoparticles(Zn O-NPs) has received significant interest worldwide particularly by the implementation of nanotechnology to synthesize particles in the nanometer region. Many microorganisms exist in the range from hundreds of nanometers to tens of micrometers. Zn O-NPs exhibit attractive antibacterial properties due to increased specific surface area as the reduced particle size leading to enhanced particle surface reactivity. Zn O is a bio-safe material that possesses photo-oxidizing and photocatalysis impacts on chemical and biological species. This review covered Zn O-NPs antibacterial activity including testing methods, impact of UV illumination, Zn O particle properties(size, concentration, morphology, and defects), particle surface modification, and minimum inhibitory concentration. Particular emphasize was given to bactericidal and bacteriostatic mechanisms with focus on generation of reactive oxygen species(ROS) including hydrogen peroxide(H2O2), OH-(hydroxyl radicals), and O2-2(peroxide). ROS has been a major factor for several mechanisms including cell wall damage due to Zn O-localized interaction, enhanced membrane permeability, internalization of NPs due to loss of proton motive force and uptake of toxic dissolved zinc ions.These have led to mitochondria weakness, intracellular outflow, and release in gene expression of oxidative stress which caused eventual cell growth inhibition and cell death. In some cases, enhanced antibacterial activity can be attributed to surface defects on Zn O abrasive surface texture. One functional application of the Zn O antibacterial bioactivity was discussed in food packaging industry where Zn O-NPs are used as an antibacterial agent toward foodborne diseases. Proper incorporation of Zn O-NPs into packaging materials can cause interaction with foodborne pathogens, thereby releasing NPs onto food surface where they come in contact with bad bacteria and cause the bacterial death and/or inhibition.展开更多
Antimicrobial peptides (AMPs) are making headlines in science because they demonstrate superior microbicidal characteristics compared to synthetic and semi-synthetic antibiotics.
Four kinds of Ce3+ exchanged montmorillonites (Ce/MMTs) were prepared by an ion-exchange reaction, and characterized with energy dispersive X-ray analysis (EDX), X-ray difference (XRD), X-ray photoelectron spectroscop...Four kinds of Ce3+ exchanged montmorillonites (Ce/MMTs) were prepared by an ion-exchange reaction, and characterized with energy dispersive X-ray analysis (EDX), X-ray difference (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The surface properties and antibacterial activity of Ce/MMTs were also investigated. The chemical compositions of Ce/MMTs were determined, and the cerium of Ce/MMTs was confirmed to be present as trivalent cerium state. The d001 basal spacings of Ce/MMTs were enlarged with the enhancement of the cerium contents, and the particles were formed with irregular shape. On increasing the Ce contents of Ce/MMTs, the special surface areas were decreased, but the total pore volumes and the average pore sizes were increased. The antibacterial activity of Ce/MMTs is increased with increasing the cerium contents, and 1.5 g/L of Ce/MMT-3 containing 11.46wt.% of curium could remove all the Staphylococcus aureus and more than 99.9% of the Escherichia coli within 24.0 h of contact. Moreover, Ce/MMTs displayed bactericidal activity.展开更多
To investigate the scientific bases for t/te traditional use of Stachy-tarpheta angustifolia. Methods: In vitro antibacterial activity of the aqueous and ethanol extract of the plant was investigated using the agar cu...To investigate the scientific bases for t/te traditional use of Stachy-tarpheta angustifolia. Methods: In vitro antibacterial activity of the aqueous and ethanol extract of the plant was investigated using the agar cup plate diffusion method. Results: The ethanol extract of the plant showed antibacterial activity against Escherichia coli, Streptococcus faecalis, Shigella dysenterme, Slaphylococcus aureus (S. aureus) , Salmonella sp. , Pseudomonas aeruginosa and Neisseria gonor-r/iaeae, while the water extract was active against Escherichia coli, Streptococcus faecalis, Shigella dysenterme, Sta-phylococcus aureus and. Pseudomonas aeruginosa. The etlianol extract exhibited higher antibacterial activity than the water extract. The minimum inhibitory concentration (MIC) and minimum bactericidal, concentration (MBC} of the ethanol extract were 0. 65 mg/mt and 0. 85 mg/ml, respectively , against S. aureus. Treatment of the extract at higher temperature, 60℃ increased the sensitivity of the test organisms to the plant extract. Phytochemical analysis indicated t/tat the plant possesses tannins, saponins as well as phenols. Conclusion: A scientific basis exists that the plant possesses antibacterial activity and it could be a probable source of therapeutic agent.展开更多
A pair of new enantiomeric furoquinoline alkaloids,(±)-zanthonitidine A(1),together with nine known ones(2-10)were isolated from the radix of Zanthoxylum nitidum.Their chemical structures were elucidated based on...A pair of new enantiomeric furoquinoline alkaloids,(±)-zanthonitidine A(1),together with nine known ones(2-10)were isolated from the radix of Zanthoxylum nitidum.Their chemical structures were elucidated based on the extensive spectroscopic analysis.The racemic mixture of 1 was separated by chiral column chromatography,and the absolute configurations of (+)-1 and(-)-1 were determined by the comparison of experimental and calculated electronic circular dichroism spectra.Antibacterial activities of compounds 1-9 were evaluated,and compounds(+)-1,(-)-1,3,7 and 8 showed antibacterial activities against Bacillus subtilis,Enterococcus faecalis or Staphylococcus aureus.展开更多
A series of novel 4'-O-carbamoyl analogs of clarithromycin were synthesized and evaluated for their in vitro antibacterial activity. All of the desired compounds showed excellent activity against erythromycin-susc...A series of novel 4'-O-carbamoyl analogs of clarithromycin were synthesized and evaluated for their in vitro antibacterial activity. All of the desired compounds showed excellent activity against erythromycin-susceptible S.pneumoniae.Particularly,4-fluorobenzyl carbamate 7a demonstrated potent activity against erythromycin-resistant S.pneumoniae encoded by the mef gene,and remarkably improved activity against erythromycin-resistant S.pneumoniae encoded by the erm gene,and the erm and mef genes.展开更多
Eight novel heterocycle-substituted dihydropyrazole derivatives were synthesized and characterized by ESI-MS, ^1H NMR and ^13C NMR. All of the compounds have been screened for their antibacterial potential in vitro ag...Eight novel heterocycle-substituted dihydropyrazole derivatives were synthesized and characterized by ESI-MS, ^1H NMR and ^13C 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 0.39-1.562 μlmL against B. subtilis.展开更多
Three kinds of new layered perovskite compounds with Ruddlesden-Popper (R-P) phase, AgrNa2-xLa2Ti3O10 (x = 0.2, 0.3 and 0.5), were synthesized by an ion-exchange reaction of Na2La2Ti3O10 with AgNO3 solution. The s...Three kinds of new layered perovskite compounds with Ruddlesden-Popper (R-P) phase, AgrNa2-xLa2Ti3O10 (x = 0.2, 0.3 and 0.5), were synthesized by an ion-exchange reaction of Na2La2Ti3O10 with AgNO3 solution. The structures of the compounds were characterized by EDX and XRD, and their antibacterial activity and light-resistance property were evaluated. The results indicated that the molecular formula of AgxNa2-xLa2Ti3O10 (x = 0.2, 0.3 and 0.5) was confirmed, and that the crystalline structure of Na2La2Ti3O10 was not obviously affected by exchange of silver ion. The minimum inhibitory concentrations (MICs) of Ag0.3Na1.7La2Ti3O10 against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) were 180 μg/mL and 240 μg/mL, respectively, while its discoloration was not observed after 24 h light ageing test.展开更多
TiO 2 nanometer thin films with photocatalytic antibacterial activity were prepared by the sol-gel method on fused quartz and soda lime glass precoated with a SiO 2 layer.The thin films were characterized by X-ray p...TiO 2 nanometer thin films with photocatalytic antibacterial activity were prepared by the sol-gel method on fused quartz and soda lime glass precoated with a SiO 2 layer.The thin films were characterized by X-ray photoelectron spectroscopy (XPS),scanning electron microscopy (SEM),and X-ray diffraction (XRD).The results show that sodium and calcium diffusion into nascent TiO 2 film is effectively retarded by the SiO 2 layer precoated on the soda lime glass.The antibacterial activity of the films was determined.The crystalline of TiO 2 nanometer thin film has important effects on the antibacterial activity of the film.展开更多
Two new Schiff base benzoyl hydrazone compounds, C14H10FN3O3 (Ⅰ) and C14H10F2N2O (Ⅱ), have been synthesized and characterized by elemental analysis, IR, UV and X-ray single-crystal diffraction. Both compounds cr...Two new Schiff base benzoyl hydrazone compounds, C14H10FN3O3 (Ⅰ) and C14H10F2N2O (Ⅱ), have been synthesized and characterized by elemental analysis, IR, UV and X-ray single-crystal diffraction. Both compounds crystallize in monoclinic, space group P21/c with a = 7.0514(14), b = 25.928(5), c = 7.7099(15), β = 111.823(2)°, V = 1308.6(4)3, Z = 4, C14H10FN3O3, Mr = 287.25, Dc = 1.458 g/cm3, μ(MoKα) = 0.115 mm-1, F(000) = 592, the final R = 0.0841 and wR = 0.2489 for 1901 observed reflections (I 2σ(I)) for I; a = 11.232(3), b =12.735(4), c = 8.612(2) , β = 90.869(3)°, V = 1231.7(6)3, Z = 4, C14H10F2N2O, Mr = 260.24, Dc = 1.403 g/cm3, μ(MoKα) = 0.111 mm-1, F(000) = 536, the final R = 0.0453 and wR = 0.1085 for 1317 observed reflections (I 2σ(I)) for Ⅱ. The antibacterial activities of both compounds against two bacteria were first studied and one compound showed considerable antibacterial activity against K. Pneumonia and S. aureus.展开更多
A new Schiff base compound, 4,4′-hydrazine-1,2-diylidenebis(methanylylidene)- bis(2- ethoxyphenol) (C18H20N2O4), has been synthesized by the condensation of 3-ethoxy-4- hydroxybenzaldehyde and 80% hydrazine hyd...A new Schiff base compound, 4,4′-hydrazine-1,2-diylidenebis(methanylylidene)- bis(2- ethoxyphenol) (C18H20N2O4), has been synthesized by the condensation of 3-ethoxy-4- hydroxybenzaldehyde and 80% hydrazine hydrate in an ethanol solution. The compound was characterized by 1H NMR, MS and single-crystal X-ray diffraction. The crystal belongs to the monoclinic system, space group P21/n with a = 5.2421(5), b = 10.3700(8), c = 14.9906(11)A, β = 97.6030(10)°, Z = 2, V= 807.73(12) A, Dc = 1.350 g/cm3, Mr = 328.36, λ(MoKa) = 0.71073 A,μ = 0.096 mm-1, F(000) = 348, R = 0.041 and wR = 0.0136. The two benzene rings are coplanar. The molecule adopts an E,E configuration about the central C=N functional bonds. A total of 3938 unique reflections were collected, of which 1440 with I 〉 2σ(I) were observed. A different type of intermolecular hydrogen bond, O-H…N, exists in the crystal. The title complex molecules are connected through hydrogen bonds to generate a two-dimensional network. The preliminary antibacterial activity results showed that the title compound exhibits antibacterial activity against Staphylococcus aureus.展开更多
The nano-TiO_2 particles were prepared by liquid hydrolysis method and characterized using XRD. Its antibacterial activity against two representative bacterial, Escherichia eoli and Staphylococcus aureus, was also stu...The nano-TiO_2 particles were prepared by liquid hydrolysis method and characterized using XRD. Its antibacterial activity against two representative bacterial, Escherichia eoli and Staphylococcus aureus, was also studied. The experimental results showed that the nano-TiO_2 caleinated at 600-700℃ contained the obvious anatase phase and exerted exeeUent antibacterial activity. The feature of antibacterial activity of nano- TiO_2 was non-strains specificity and exerted best antibacterial activity at concentration of 0.8 g/L.展开更多
In recent years, fused heterocycles have been reported to possess important properties in synthesis and pharmacology. Especially, s-triazolo, 3,4-thiadiazole derivatives have been attracting much attention for chemist...In recent years, fused heterocycles have been reported to possess important properties in synthesis and pharmacology. Especially, s-triazolo, 3,4-thiadiazole derivatives have been attracting much attention for chemists and pharmacologists because they show broad spectra of biological activities, such as antifungal, antibacterial, hy-展开更多
Functional composite films were successfully prepared from cellulose, graphite(GP), and polyaniline(PANI) using a combination of physical and chemical processes. Cellulosewasdissolved in N-methylmorpholine-N-oxide mon...Functional composite films were successfully prepared from cellulose, graphite(GP), and polyaniline(PANI) using a combination of physical and chemical processes. Cellulosewasdissolved in N-methylmorpholine-N-oxide monohydrate(NMMO) and regenerated in water to form the matrix. GP was dispersed in the NMMO solvent prior to the dissolution of the cellulose, and PANI was deposited on the surfaces of the cellulose/GP films by in situ chemical polymerization. The structures of the PANI/cellusose/GP composite films were investigated using X-ray diffraction analysis, Fourier transform infrared spectroscopy, scanning electron microscopy(SEM), and SEM/energy-dispersive X-ray spectroscopy. The mechanical strengths, thermal stabilities, conductivities, and antibacterial activities of the films were studied in detail. The results showed that GP formed a multilayered structure in the cellulose matrix and that the PANI nanoparticles were tightly wrapped on the film surface. The film thickness increased from 40 mm to 100 mm after the addition of GP and PANI. The tensile strength of the composite films was 80~107 MPa, with the elongation at break being 3%~10%. The final residual weight of the composite films was as high as 65%, and the conductivity of the composite films reached 14.36 S/m. The cellulose matrix ensured that the films were flexible and exhibited desirable mechanical properties, while the GP filler significantly improved the thermal stability of the films. The PANI coating acted as a protective layer during burning and provided good electrical conductivity and antibacterial activity against Escherichia coli; both of these characteristics were slightly enhanced by the incorporation of GP. These PANI/cellulose/GP composite films should be suitable for use in electronics, antistatic packing, and numerous other applications.展开更多
A new ternary copper(Ⅱ) complex, [C43H27Cu2N7O5][C14H6CuN2O8]'6.5H2O, has been synthesized by the reaction of copper sulfate, 2,6-pyridinedicarboxylic acid and 1,10- phenanthroline (phen), and characterized by e...A new ternary copper(Ⅱ) complex, [C43H27Cu2N7O5][C14H6CuN2O8]'6.5H2O, has been synthesized by the reaction of copper sulfate, 2,6-pyridinedicarboxylic acid and 1,10- phenanthroline (phen), and characterized by elemental analysis, IR, UV and X-ray single-crystal diffraction. It crystallizes in triclinic, space group P1, with a = 14.379(5), b = 15.510(5), c = 15.835(6) A, a = 78.567(6), β = 63.594(6), y = 81.287(6)°, V= 3092.1(19) A3, C57H46Cn3N9O19.5, Mr = 1359.54, Z = 2, Dc = 1.446 Mg/m3, λ(MoKa) = 0.71073 A,μ = 1.101 mm^-1, F(000) = 1362, S = 1.071, the final R = 0.0718 and wR = 0.11960 for 10705 observer reflections (I 〉 2σ(I)). The structure unit of the title complex consisfs of a mononuclear part and a di-nuclear part, and the three copper ions show three coordination modes. Each 6-coordinated geometry of the Cu atom is a distorted octahedral coordination geometry. The 3D supramolecular system is formed by the hydrogen bond O-H-O and π-π stacking interaction between neighboring single cells. The antibacterial activity of the title complex is also studied.展开更多
Filamentous microalgae from genus Tribonema are promising sustainable sources of omega-7 palmitoleic acid,but their ability to accumulate this compound varies among species and depends on the initial nitrogen concentr...Filamentous microalgae from genus Tribonema are promising sustainable sources of omega-7 palmitoleic acid,but their ability to accumulate this compound varies among species and depends on the initial nitrogen concentration(INC)supply.In this study,the palmitoleic acid accumulation capacities of five Tribonema species were examined under three different INCs to select the alga species with the highest production.Results showed that a high INC was associated with increased palmitoleic acid accumulation but led to decreased biomass concentration in all tested species.In particular,T.minus grown at 18 mmol L^(−1)INC had the highest palmitoleic acid content(20.72%of dry weight)and productivity(90.88 mg L^(−1)d−1).The combination of alkali metal freezing precipitation(AMFP)and urea complexation successfully isolated and enriched palmitoleic acid from T.minus and obtained a purity of 80.11%and a yield of 7.39 g(100 g)^(−1) of algal powder.The compound was identified as(9Z)-hexadecenoic acid(C16:1ω-7).Antibacterial activity evaluation for the highly concentrated palmitoleic acid(10 mg mL^(−1))against Streptococcus agalactiae revealed the formation of a 12.10 mm-diameter inhibition zone and the minimum inhibitory concentration of 31.25μg mL^(−1),indicating that palmitoleic acid is an effective antibacterial agent.This study is the first to report that palmitoleic acid derived from T.minus can antagonize S.agalactiae,which further broadens the potential application of Tribonema biomass in green aquaculture.展开更多
Tetradecyldimethylbenzyl ammonium salt(TDMBA) cations were intercalated into sodium montmorillonite(Na-MMT) by an ion exchange reaction. The resulting TDMBA-MMT was characterized by Fourier-transform infrared spec...Tetradecyldimethylbenzyl ammonium salt(TDMBA) cations were intercalated into sodium montmorillonite(Na-MMT) by an ion exchange reaction. The resulting TDMBA-MMT was characterized by Fourier-transform infrared spectroscopy(FTIR), thermogravimetric analysis(TGA), and X-ray diffraction(XRD). Moreover, the antibacterial activity and water-resistance of TDMBA-MMT were investigated. The results show that TDMBA cations are intercalated into the Na-MMT. The onset temperature of decomposition of TDMBA cations in TDMBA-MMT is raised about 60 ℃ higher than that of tetradecyldimethylbenzyl ammonium chloride(TDMBACl), and the d(001) spacing enlarged from 1.23 nm to 2.10 nm. 0.1 mg/mL TDMBA-MMT is fully enough to kill all the Staphylococci aureus(S, aureus) and more than 99.99% of the Escherichia coli(E, coli) in a sample solution within 6.0 h touch, and the TDMBA-MMT also shows long acting properties.展开更多
基金supported by the National Natural Science Foundation of China(No.32072969)the National Key R&D Program of China(No.2022YFD2401002)+1 种基金the Natural Science Foundation of Fujian Province(No.2022 J01325)the Open Research Fund Program of Fujian Provincial Key Laboratory of Marine Fishery Resources and Eco-Environment(No.Z822280).
文摘Lysozyme(EC3.2.1.17)plays an important role in the immune response;as a nonspecific immune factor,it can resist causative agents.Lysozyme can be divided into c-type and g-type in fish.In a previous study,through genome-wide association analysis,the g-type lysozyme gene,which is named NaLyg in yellow drum(Nibea albiflora),was found to be a key candidate gene for disease resistance in response to Vibrio harveyi infection.The cDNA of NaLyg was 1025 bp,including four exons and three introns,and its open reading frame(ORF)had a full-length of 582 bp,encoding 193 amino acids.NaLyg was found to be conserved during evolution through bioinformatic analyses.The NaLyg protein possessed a sugar binding domain and three catalytic sites,including Glu71,Asp84 and Asp101.Quantitative qRT-PCR results confirmed that NaLyg gene mRNA was visibly increased after V.harveyi infection.The NaLyg protein purified by prokaryotic expression killed some gram-negative bacterial pathogens by inducing cell wall destruction,including V.harveyi,Aeromonas hydrophila and Edwardsiella tarda.Moreover,the NaLyg protein killed two gram-positive bacteria,Bacillus subtilis and Staphylococcus aureus.Taken together,the experimental results suggested that the NaLyg protein of N.albiflora played an important role in fighting bacterial infections.
基金supported by the National Key Research and Development Project(No.2019YFC0312103)the Open Fund of Shandong Key Laboratory of Corrosion Science(No.KLCS201905)。
文摘Carboxymethyl starch/silver oxide nanocomposites(CMS-Ag_(2)O NCs)were successfully fabricated by modifying carboxymethyl starch(CMS)with Ag_(2)O obtained from an aqueous AgNO_(3)solution as silver source.Ag_(2)O nanoparticles(NPs)formed on the surface of CMS by ion exchange.Based on SEM images,the diameters of Ag_(2)O NPs were determined to be between 50 and 100 nm.From the XRD spectra of CMS-Ag_(2)O NCs,the new diffraction peaks appeared at 33.88°and 38.08°,which were attributed to the Ag_(2)O NPs.According to the XPS analysis,Ag 3d_(5/2)and Ag 3d_(3/2)peaks in CMS-Ag_(2)O NCs were fitted into two main peaks centered at 367.6 eV and 373.6 eV,which were attributed to Ag^(+).The antibacterial efficiencies of CMS-Ag_(2)O NCs against Escherichia coli,Staphylococcus aureus,Pseudoalteromonas tetraodonis,Micrococcus luteus,and Shewanella putrefaciens were determined to be 99.6%,99.7%,99.4%,99.5%,and 99.6%,respectively.The antibacterial efficiencies of CMS-Ag_(2)O NCs against the bacterial species were all greater than 99%.Therefore,these results indicated that CMS-Ag_(2)O NCs was highly effective as a bactericidal agent against multiple bacterial species.CMS-Ag_(2)O NCs can be further applied to antifouling coating.
基金support from a research university Grant number 1001/PFIZIK/814174 of Universiti Sains Malaysia(USM)
文摘Antibacterial activity of zinc oxide nanoparticles(Zn O-NPs) has received significant interest worldwide particularly by the implementation of nanotechnology to synthesize particles in the nanometer region. Many microorganisms exist in the range from hundreds of nanometers to tens of micrometers. Zn O-NPs exhibit attractive antibacterial properties due to increased specific surface area as the reduced particle size leading to enhanced particle surface reactivity. Zn O is a bio-safe material that possesses photo-oxidizing and photocatalysis impacts on chemical and biological species. This review covered Zn O-NPs antibacterial activity including testing methods, impact of UV illumination, Zn O particle properties(size, concentration, morphology, and defects), particle surface modification, and minimum inhibitory concentration. Particular emphasize was given to bactericidal and bacteriostatic mechanisms with focus on generation of reactive oxygen species(ROS) including hydrogen peroxide(H2O2), OH-(hydroxyl radicals), and O2-2(peroxide). ROS has been a major factor for several mechanisms including cell wall damage due to Zn O-localized interaction, enhanced membrane permeability, internalization of NPs due to loss of proton motive force and uptake of toxic dissolved zinc ions.These have led to mitochondria weakness, intracellular outflow, and release in gene expression of oxidative stress which caused eventual cell growth inhibition and cell death. In some cases, enhanced antibacterial activity can be attributed to surface defects on Zn O abrasive surface texture. One functional application of the Zn O antibacterial bioactivity was discussed in food packaging industry where Zn O-NPs are used as an antibacterial agent toward foodborne diseases. Proper incorporation of Zn O-NPs into packaging materials can cause interaction with foodborne pathogens, thereby releasing NPs onto food surface where they come in contact with bad bacteria and cause the bacterial death and/or inhibition.
基金supported by grants from the Project of Jilin province Technology Platform(NO.20070210)the Young Research Fond of Jilin University
文摘Antimicrobial peptides (AMPs) are making headlines in science because they demonstrate superior microbicidal characteristics compared to synthetic and semi-synthetic antibiotics.
基金Project supported by the National Natural Science Foundation of China (20676049 and 20871058), the Foundation of Enterprise-University-Research Institute Cooperation from Guangdong Province and Ministry of Education of China (2007B090400105, 2008A010500005), the Natural Science Foundation of Guangdong Province of China (05200555 and 06104481) and the Open Foundation of Guangdong Provincial Key Laboratory of Applied Microbiology (SWKF200704)
文摘Four kinds of Ce3+ exchanged montmorillonites (Ce/MMTs) were prepared by an ion-exchange reaction, and characterized with energy dispersive X-ray analysis (EDX), X-ray difference (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The surface properties and antibacterial activity of Ce/MMTs were also investigated. The chemical compositions of Ce/MMTs were determined, and the cerium of Ce/MMTs was confirmed to be present as trivalent cerium state. The d001 basal spacings of Ce/MMTs were enlarged with the enhancement of the cerium contents, and the particles were formed with irregular shape. On increasing the Ce contents of Ce/MMTs, the special surface areas were decreased, but the total pore volumes and the average pore sizes were increased. The antibacterial activity of Ce/MMTs is increased with increasing the cerium contents, and 1.5 g/L of Ce/MMT-3 containing 11.46wt.% of curium could remove all the Staphylococcus aureus and more than 99.9% of the Escherichia coli within 24.0 h of contact. Moreover, Ce/MMTs displayed bactericidal activity.
文摘To investigate the scientific bases for t/te traditional use of Stachy-tarpheta angustifolia. Methods: In vitro antibacterial activity of the aqueous and ethanol extract of the plant was investigated using the agar cup plate diffusion method. Results: The ethanol extract of the plant showed antibacterial activity against Escherichia coli, Streptococcus faecalis, Shigella dysenterme, Slaphylococcus aureus (S. aureus) , Salmonella sp. , Pseudomonas aeruginosa and Neisseria gonor-r/iaeae, while the water extract was active against Escherichia coli, Streptococcus faecalis, Shigella dysenterme, Sta-phylococcus aureus and. Pseudomonas aeruginosa. The etlianol extract exhibited higher antibacterial activity than the water extract. The minimum inhibitory concentration (MIC) and minimum bactericidal, concentration (MBC} of the ethanol extract were 0. 65 mg/mt and 0. 85 mg/ml, respectively , against S. aureus. Treatment of the extract at higher temperature, 60℃ increased the sensitivity of the test organisms to the plant extract. Phytochemical analysis indicated t/tat the plant possesses tannins, saponins as well as phenols. Conclusion: A scientific basis exists that the plant possesses antibacterial activity and it could be a probable source of therapeutic agent.
基金supported by the National Natural Science Foundation of China(31470428,21702231)the National New Drug Innovation Major Project of China(2017ZX09309027)the Program for Jiangsu Province Innovative Research Team,the Fund for Introduction of High-level Talents from China Pharmaceu-tical University and the Fundamental Research Funds for the Central Universities(2632017PY19).
文摘A pair of new enantiomeric furoquinoline alkaloids,(±)-zanthonitidine A(1),together with nine known ones(2-10)were isolated from the radix of Zanthoxylum nitidum.Their chemical structures were elucidated based on the extensive spectroscopic analysis.The racemic mixture of 1 was separated by chiral column chromatography,and the absolute configurations of (+)-1 and(-)-1 were determined by the comparison of experimental and calculated electronic circular dichroism spectra.Antibacterial activities of compounds 1-9 were evaluated,and compounds(+)-1,(-)-1,3,7 and 8 showed antibacterial activities against Bacillus subtilis,Enterococcus faecalis or Staphylococcus aureus.
基金supported by Major R&D Program of New Drugs-National S&T Key Special Subject of China (No.2009ZX09103-115)National Natural Science Foundation of China(No.20872081)Natural Science Foundation of Shandong(No.Y2006C31)
文摘A series of novel 4'-O-carbamoyl analogs of clarithromycin were synthesized and evaluated for their in vitro antibacterial activity. All of the desired compounds showed excellent activity against erythromycin-susceptible S.pneumoniae.Particularly,4-fluorobenzyl carbamate 7a demonstrated potent activity against erythromycin-resistant S.pneumoniae encoded by the mef gene,and remarkably improved activity against erythromycin-resistant S.pneumoniae encoded by the erm gene,and the erm and mef genes.
基金the opening foundation of the Key Laboratory of Green Pesticide and Agricultural Bioengineering,Ministry of Education,Guizhou University,(No.2008GDGP0105)supported by the Young College Teachers Research Projects of Anhui Province(No.2008JQ1030)the Young College Teachers Research Projects of Anhui University of Technology(No.QZ200809).
文摘Eight novel heterocycle-substituted dihydropyrazole derivatives were synthesized and characterized by ESI-MS, ^1H NMR and ^13C 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 0.39-1.562 μlmL against B. subtilis.
文摘Three kinds of new layered perovskite compounds with Ruddlesden-Popper (R-P) phase, AgrNa2-xLa2Ti3O10 (x = 0.2, 0.3 and 0.5), were synthesized by an ion-exchange reaction of Na2La2Ti3O10 with AgNO3 solution. The structures of the compounds were characterized by EDX and XRD, and their antibacterial activity and light-resistance property were evaluated. The results indicated that the molecular formula of AgxNa2-xLa2Ti3O10 (x = 0.2, 0.3 and 0.5) was confirmed, and that the crystalline structure of Na2La2Ti3O10 was not obviously affected by exchange of silver ion. The minimum inhibitory concentrations (MICs) of Ag0.3Na1.7La2Ti3O10 against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) were 180 μg/mL and 240 μg/mL, respectively, while its discoloration was not observed after 24 h light ageing test.
文摘TiO 2 nanometer thin films with photocatalytic antibacterial activity were prepared by the sol-gel method on fused quartz and soda lime glass precoated with a SiO 2 layer.The thin films were characterized by X-ray photoelectron spectroscopy (XPS),scanning electron microscopy (SEM),and X-ray diffraction (XRD).The results show that sodium and calcium diffusion into nascent TiO 2 film is effectively retarded by the SiO 2 layer precoated on the soda lime glass.The antibacterial activity of the films was determined.The crystalline of TiO 2 nanometer thin film has important effects on the antibacterial activity of the film.
基金supported by the National Natural Science Foundation of China(No.81102791)
文摘Two new Schiff base benzoyl hydrazone compounds, C14H10FN3O3 (Ⅰ) and C14H10F2N2O (Ⅱ), have been synthesized and characterized by elemental analysis, IR, UV and X-ray single-crystal diffraction. Both compounds crystallize in monoclinic, space group P21/c with a = 7.0514(14), b = 25.928(5), c = 7.7099(15), β = 111.823(2)°, V = 1308.6(4)3, Z = 4, C14H10FN3O3, Mr = 287.25, Dc = 1.458 g/cm3, μ(MoKα) = 0.115 mm-1, F(000) = 592, the final R = 0.0841 and wR = 0.2489 for 1901 observed reflections (I 2σ(I)) for I; a = 11.232(3), b =12.735(4), c = 8.612(2) , β = 90.869(3)°, V = 1231.7(6)3, Z = 4, C14H10F2N2O, Mr = 260.24, Dc = 1.403 g/cm3, μ(MoKα) = 0.111 mm-1, F(000) = 536, the final R = 0.0453 and wR = 0.1085 for 1317 observed reflections (I 2σ(I)) for Ⅱ. The antibacterial activities of both compounds against two bacteria were first studied and one compound showed considerable antibacterial activity against K. Pneumonia and S. aureus.
基金Supported by the Fundamental Research Funds for the Central Universities (2012ZM0035)
文摘A new Schiff base compound, 4,4′-hydrazine-1,2-diylidenebis(methanylylidene)- bis(2- ethoxyphenol) (C18H20N2O4), has been synthesized by the condensation of 3-ethoxy-4- hydroxybenzaldehyde and 80% hydrazine hydrate in an ethanol solution. The compound was characterized by 1H NMR, MS and single-crystal X-ray diffraction. The crystal belongs to the monoclinic system, space group P21/n with a = 5.2421(5), b = 10.3700(8), c = 14.9906(11)A, β = 97.6030(10)°, Z = 2, V= 807.73(12) A, Dc = 1.350 g/cm3, Mr = 328.36, λ(MoKa) = 0.71073 A,μ = 0.096 mm-1, F(000) = 348, R = 0.041 and wR = 0.0136. The two benzene rings are coplanar. The molecule adopts an E,E configuration about the central C=N functional bonds. A total of 3938 unique reflections were collected, of which 1440 with I 〉 2σ(I) were observed. A different type of intermolecular hydrogen bond, O-H…N, exists in the crystal. The title complex molecules are connected through hydrogen bonds to generate a two-dimensional network. The preliminary antibacterial activity results showed that the title compound exhibits antibacterial activity against Staphylococcus aureus.
基金Funded by the Research Fund of Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province(No.AE201037the Foundation for Talent Recruitment of Yancheng Institute of Technology(No.XKR2011007)
文摘The nano-TiO_2 particles were prepared by liquid hydrolysis method and characterized using XRD. Its antibacterial activity against two representative bacterial, Escherichia eoli and Staphylococcus aureus, was also studied. The experimental results showed that the nano-TiO_2 caleinated at 600-700℃ contained the obvious anatase phase and exerted exeeUent antibacterial activity. The feature of antibacterial activity of nano- TiO_2 was non-strains specificity and exerted best antibacterial activity at concentration of 0.8 g/L.
文摘Extracts of 16 natural medicine powders {Galla chinensis,Malloti cortex,Cassiae semen,Sophorae radix,Myricae cortex,Crataegi fructus,Gambit,Mume fructus,Geranii herba,Phellodendri cortex,Coptidis rhizoma,Swertiae herba,and Cinnamomi cortex) were assayed for reactive oxygen concentrations using the peroxyoxalate chemiluminescent detection system.High luminescence intensity was observed in Galla chinensis,Geranii herba,Malloti cortex,Myricae cortex,and Cinnamomi cortex.Additional experiments identified the reactive oxygen species as hydrogen peroxide.Galla chinensis generated 2.4 × 10^(-4) mol/L hydrogen peroxide from a 1 mg/mL solution.In bacterial growth tests,Galla chinensis extract had antibacterial activity against Escherichia coli.Staphylococcus aureus,Bacteroides thetaiotaomicron,Campylobacter sputorum biovar sputorum.Streptococcus salivarius thermophilus,Lactobacillus casei,and Bifidobacterium longum infantis.This antibacterial activity was decreased by the addition of catalase.It revealed that hydrogen peroxide which Galla chinensis produced participated in antibacterial activity.
文摘In recent years, fused heterocycles have been reported to possess important properties in synthesis and pharmacology. Especially, s-triazolo, 3,4-thiadiazole derivatives have been attracting much attention for chemists and pharmacologists because they show broad spectra of biological activities, such as antifungal, antibacterial, hy-
基金financial support from the International S&T Cooperation Program of China (No.2015DFG31860)the National Science Foundation of China for the Key Projects (Nos.31430092 and 31110103902)
文摘Functional composite films were successfully prepared from cellulose, graphite(GP), and polyaniline(PANI) using a combination of physical and chemical processes. Cellulosewasdissolved in N-methylmorpholine-N-oxide monohydrate(NMMO) and regenerated in water to form the matrix. GP was dispersed in the NMMO solvent prior to the dissolution of the cellulose, and PANI was deposited on the surfaces of the cellulose/GP films by in situ chemical polymerization. The structures of the PANI/cellusose/GP composite films were investigated using X-ray diffraction analysis, Fourier transform infrared spectroscopy, scanning electron microscopy(SEM), and SEM/energy-dispersive X-ray spectroscopy. The mechanical strengths, thermal stabilities, conductivities, and antibacterial activities of the films were studied in detail. The results showed that GP formed a multilayered structure in the cellulose matrix and that the PANI nanoparticles were tightly wrapped on the film surface. The film thickness increased from 40 mm to 100 mm after the addition of GP and PANI. The tensile strength of the composite films was 80~107 MPa, with the elongation at break being 3%~10%. The final residual weight of the composite films was as high as 65%, and the conductivity of the composite films reached 14.36 S/m. The cellulose matrix ensured that the films were flexible and exhibited desirable mechanical properties, while the GP filler significantly improved the thermal stability of the films. The PANI coating acted as a protective layer during burning and provided good electrical conductivity and antibacterial activity against Escherichia coli; both of these characteristics were slightly enhanced by the incorporation of GP. These PANI/cellulose/GP composite films should be suitable for use in electronics, antistatic packing, and numerous other applications.
文摘A new ternary copper(Ⅱ) complex, [C43H27Cu2N7O5][C14H6CuN2O8]'6.5H2O, has been synthesized by the reaction of copper sulfate, 2,6-pyridinedicarboxylic acid and 1,10- phenanthroline (phen), and characterized by elemental analysis, IR, UV and X-ray single-crystal diffraction. It crystallizes in triclinic, space group P1, with a = 14.379(5), b = 15.510(5), c = 15.835(6) A, a = 78.567(6), β = 63.594(6), y = 81.287(6)°, V= 3092.1(19) A3, C57H46Cn3N9O19.5, Mr = 1359.54, Z = 2, Dc = 1.446 Mg/m3, λ(MoKa) = 0.71073 A,μ = 1.101 mm^-1, F(000) = 1362, S = 1.071, the final R = 0.0718 and wR = 0.11960 for 10705 observer reflections (I 〉 2σ(I)). The structure unit of the title complex consisfs of a mononuclear part and a di-nuclear part, and the three copper ions show three coordination modes. Each 6-coordinated geometry of the Cu atom is a distorted octahedral coordination geometry. The 3D supramolecular system is formed by the hydrogen bond O-H-O and π-π stacking interaction between neighboring single cells. The antibacterial activity of the title complex is also studied.
基金supported by the Jiangsu Provincial Natural Science Foundation(No.BK20200734)the Hubei Provincial Natural Science Foundation(No.2021CFB224)+3 种基金the Engineering Research Center for Tropical and Subtropical Aquatic Ecological Engineering,Ministry of Education,Jinan University,P.R.China(No.2021A0401)the Research and Innovation Initiatives of Wuhan Polytechnic University(WHPU)(No.2021Y06)the Hubei Key Laboratory for Processing and Transformation of Agricultural Products(WHPU,China)(No.2020HBSQGDKFB17)the Sinopec Joint Program of China Petroleum and Chemical Corporation(No.ST18005-2).
文摘Filamentous microalgae from genus Tribonema are promising sustainable sources of omega-7 palmitoleic acid,but their ability to accumulate this compound varies among species and depends on the initial nitrogen concentration(INC)supply.In this study,the palmitoleic acid accumulation capacities of five Tribonema species were examined under three different INCs to select the alga species with the highest production.Results showed that a high INC was associated with increased palmitoleic acid accumulation but led to decreased biomass concentration in all tested species.In particular,T.minus grown at 18 mmol L^(−1)INC had the highest palmitoleic acid content(20.72%of dry weight)and productivity(90.88 mg L^(−1)d−1).The combination of alkali metal freezing precipitation(AMFP)and urea complexation successfully isolated and enriched palmitoleic acid from T.minus and obtained a purity of 80.11%and a yield of 7.39 g(100 g)^(−1) of algal powder.The compound was identified as(9Z)-hexadecenoic acid(C16:1ω-7).Antibacterial activity evaluation for the highly concentrated palmitoleic acid(10 mg mL^(−1))against Streptococcus agalactiae revealed the formation of a 12.10 mm-diameter inhibition zone and the minimum inhibitory concentration of 31.25μg mL^(−1),indicating that palmitoleic acid is an effective antibacterial agent.This study is the first to report that palmitoleic acid derived from T.minus can antagonize S.agalactiae,which further broadens the potential application of Tribonema biomass in green aquaculture.
基金Supported by the National Natural Science Fundation of China(Nos.20676049,20871058 and 20971028)the Foundation of Enterprise-University-Research Institute Cooperation from Guangdong Province and Ministry of Education of China(Nos. 2007B090400105 and 2008A010500005)
文摘Tetradecyldimethylbenzyl ammonium salt(TDMBA) cations were intercalated into sodium montmorillonite(Na-MMT) by an ion exchange reaction. The resulting TDMBA-MMT was characterized by Fourier-transform infrared spectroscopy(FTIR), thermogravimetric analysis(TGA), and X-ray diffraction(XRD). Moreover, the antibacterial activity and water-resistance of TDMBA-MMT were investigated. The results show that TDMBA cations are intercalated into the Na-MMT. The onset temperature of decomposition of TDMBA cations in TDMBA-MMT is raised about 60 ℃ higher than that of tetradecyldimethylbenzyl ammonium chloride(TDMBACl), and the d(001) spacing enlarged from 1.23 nm to 2.10 nm. 0.1 mg/mL TDMBA-MMT is fully enough to kill all the Staphylococci aureus(S, aureus) and more than 99.99% of the Escherichia coli(E, coli) in a sample solution within 6.0 h touch, and the TDMBA-MMT also shows long acting properties.