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New Antibacterial Dihydropyrones Induced by Co-Culture of Penicillium crustosum PRB-2 and Penicillium citrinum HDN11-186
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作者 YU Guihong ZHOU Luning +1 位作者 WU Guangwei LI Dehai 《Journal of Ocean University of China》 CAS CSCD 2024年第1期216-220,共5页
Two new dihydropyrones,rhytismatones C(1)and D(2),and a known compound,penicillenol A1(3),were isolated from the co-culture broth of the deep-sea-derived fungus Penicillium crustosum PRB-2 and Suaeda salsa-derived end... Two new dihydropyrones,rhytismatones C(1)and D(2),and a known compound,penicillenol A1(3),were isolated from the co-culture broth of the deep-sea-derived fungus Penicillium crustosum PRB-2 and Suaeda salsa-derived endophytic fungus Peni-cillium citrinum HDN11-186.Their structures were elucidated through comprehensive analysis of nuclear magnetic resonance(NMR)spectra and mass spectra.The absolute configurations of new compounds were determined by calculating the electronic circular di-chroism(ECD)spectrum.UPLC-MS data showed that compounds 1–3 could only be detected in the media of co-culture,suggesting new biosynthetic pathways were activated in the co-cultured fungi.Compound 1 showed obvious antibacterial activities against Pro-teus sp.MMBC-1002 and Bacillus subtilis MMBC-1004 with minimum inhibitory concentration(MIC)both at 25μmolL^(-1). 展开更多
关键词 CO-CULTURE Penicillium crustosum Penicillium citrinum dihydropyrones antibacterial activity
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Molecular Characterization and Antibacterial Activity of a G-Type Lysozyme in Yellow Drum(Nibea albiflora)
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作者 XIAO Yao LI Jiacheng +2 位作者 TIAN Qianqian WU Baolan HAN Fang 《Journal of Ocean University of China》 CAS CSCD 2024年第2期477-486,共10页
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
关键词 Nibea albiflora innate immunity Vibrio harveyi g-type lysozyme antibacterial activity
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Superwetting Ag/α-Fe_(2)O_(3) anchored mesh with enhanced photocatalytic and antibacterial activities for efficient water purification
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作者 Jiakai Li Changpeng Lv +5 位作者 Jiajia Song Xiaoling Zhang Xizhen Huang Yingzhuo Ma Haijie Cao Na Liu 《Green Energy & Environment》 SCIE EI CAS CSCD 2024年第1期89-103,共15页
Superwetting materials have drawn unprecedented attention in the treatment of oily wastewater due to their preferable anti-fouling property and selective oil/water separation.However,it is still a challenge to fabrica... Superwetting materials have drawn unprecedented attention in the treatment of oily wastewater due to their preferable anti-fouling property and selective oil/water separation.However,it is still a challenge to fabricate multifunctional and environmentally friendly materials,which can be stably applied to purify the actual complicated wastewater.Here,a Ag/Ag/α-Fe_(2)O_(3) heterostructure anchored copper mesh was intentionally synthesized using a facile two-step hydrothermal method.The resultant mesh with superhydrophilicity and underwater superoleophobicity was capable of separating various oil/water mixtures with superior separation efficiency and high permeationflux driven by gravity.Benefiting from the joint effects of the smaller band gap of Ag/α-Fe_(2)O_(3) heterojunction,inherent antibacterial capacity of Ag/α-Fe_(2)O_(3) and Ag nanoparticles,favorable conductive substrate,as well as the hierarchical structure with superwettability,such mesh presented remarkably enhanced degradation capability toward organic dyes under visible light irradiation and antibacterial activity against both Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)compared with the pure Ag/α-Fe_(2)O_(3) coated mesh.Impressively,the mesh exhibited bifunctional water purification performance,in which organic dyes were eliminated simultaneously from water during oil/water separation in onefiltration process.More importantly,this mesh behaved exceptional chemical resistance,mechanical stability and long-term reusability.Therefore,this material with multifunctional integration may hold promising potential for steady water purification in practice. 展开更多
关键词 Superwetting Ag/α-Fe_(2)O_(3)heterostructure Enhanced photocatalytic and antibacterial activities Water purification Long-term reusability
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Semisynthetic Derivatives of Sissotrin Isolated from Trifolium baccarinii Chiov. (Fabaceae) and Evaluation of Their Antibacterial Activities
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作者 Donald Léonel Feugap Tsamo Cyrille Ngoufack Tagousop +2 位作者 Arnaud Joseph Nguetse Dongmo Laurence Voutquenne-Nazabadioko David Ngnokam 《Advances in Biological Chemistry》 CAS 2024年第1期27-39,共13页
Starting from sissotrin (1), a natural isoflavonoid isolated from Trifolium baccarinii (Fabaceae), one new semisynthetic derivative, 6-nitrobiochanin A (1b) and two known derivatives, 8-nitrobiochanin A (1a) and 2&quo... Starting from sissotrin (1), a natural isoflavonoid isolated from Trifolium baccarinii (Fabaceae), one new semisynthetic derivative, 6-nitrobiochanin A (1b) and two known derivatives, 8-nitrobiochanin A (1a) and 2",3",4",6"-tetraacetylsissotrin (1c) have been obtained after performing nitration and acetylation reactions. Their structures were assigned after interpretation of their spectrometric (HR-ESI-MS) and spectroscopic (NMR 1D and 2D) data and by comparison with those reported in the literature. The substrate as well as the semisynthetic derivatives were evaluated for their antibacterial activities against six strains. The results reveal that they are inactive or weakly active on the strains tested with the exception of 8-nitrobiochanin A (1a) which showed moderate activity (MIC = 62.5 μg∙mL<sup>−1</sup>) on Staphylococcus aureus ATCC 43300. 展开更多
关键词 Trifolium baccarinii ISOFLAVONOID NITRATION ACETYLATION antibacterial Activity
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Determination of reactive oxygen generated from natural medicines and their antibacterial activity 被引量:8
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作者 Noriko Tajima Makiko Takasaki +3 位作者 Haruka Fukamachi Takeshi Igarashi Yoshijiro Nakajima Hidetoshi Arakawa 《Journal of Pharmaceutical Analysis》 SCIE CAS 2016年第4期214-218,共5页
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 herb... 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. 展开更多
关键词 Galla Chinensis Natural medicines Hydrogen peroxide antibacterial activity
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Novel 18β-glycyrrhetinic acid amide derivatives show dual-acting capabilities for controlling plant bacterial diseases through ROS-mediated antibacterial efficiency and activating plant defense responses 被引量:2
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作者 SONG Ying-lian LIU Hong-wu +7 位作者 YANG Yi-hong HE Jing-jing YANG Bin-xin YANG Lin-li ZHOU Xiang LIU Li-wei WANG Pei-yi YANG Song 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2023年第9期2759-2771,共13页
Natural products have long been a crucial source of,or provided inspiration for new agrochemical discovery.Naturally occurring 18β-glycyrrhetinic acid shows broad-spectrum bioactivities and is a potential skeleton fo... Natural products have long been a crucial source of,or provided inspiration for new agrochemical discovery.Naturally occurring 18β-glycyrrhetinic acid shows broad-spectrum bioactivities and is a potential skeleton for novel drug discovery.To extend the utility of 18β-glycyrrhetinic acid for agricultural uses,a series of novel 18β-glycyrrhetinic acid amide derivatives were prepared and evaluated for their antibacterial potency.Notably,compound 5k showed good antibacterial activity in vitro against Xanthomonas oryzae pv.oryzae(Xoo,EC50=3.64 mg L–1),and excellent protective activity(54.68%)against Xoo in vivo.Compound 5k induced excessive production and accumulation of reactive oxygen species in the tested pathogens,resulting in damaging the bacterial cell envelope.More interestingly,compound 5k could increase the activities of plant defense enzymes including catalase,superoxide dismutase,peroxidase,and phenylalanine ammonia lyase.Taken together,these enjoyable results suggested that designed compounds derived from 18β-glycyrrhetinic acid showed potential for controlling intractable plant bacterial diseases by disturbing the balance of the phytopathogen’s redox system and activating the plant defense system. 展开更多
关键词 18β-glycyrrhetinic acid antibacterial activities defense enzyme activity reactive oxygen species
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Antibacterial Chitosan-Gelatin Microcapsules Modified with Green-Synthesized Silver Nanoparticles for Food Packaging 被引量:2
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作者 Long Li Yanan Lu +3 位作者 Yu Chen Jiayi Bian Li Wang Li Li 《Journal of Renewable Materials》 SCIE EI 2023年第1期291-307,共17页
Silver nanoparticles(Ag NPs)are an effective antibacterial agent,but their application in food packaging is limited due to their easy agglomeration and oxidation.In this study,antibacterial microcapsules were fabricat... Silver nanoparticles(Ag NPs)are an effective antibacterial agent,but their application in food packaging is limited due to their easy agglomeration and oxidation.In this study,antibacterial microcapsules were fabricated using Ginkgo biloba essential oil(GBEO)as core material and chitosan and type B gelatin biopolymer as capsule mate-rials.These antibacterial microcapsules were then modified with green-synthesized Ag NPs,blended into the bio-polymer polylactic acid(PLA),and finally formed as films.Physicochemical properties and antibacterial activity against Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)were evaluated.Results showed that the prepared antibacterial PLA films exhibited excellent antibacterial activity against foodborne pathogens.Its TVC exceeded the limit value of 7 log CFU/g at 7 days compared with the 5 days of pure PLA films.Therefore,these films can extend the shelf life of grass carp fillets by 2–3 days under refrigeration. 展开更多
关键词 Silver nanoparticles chitosan GELATIN MICROCAPSULES antibacterial activity food packaging
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Synthesis and Excellent Antibacterial Activity of Ag_(2)O-Loaded Carboxymethyl Starch Nanocomposites
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作者 WAN Lina YU Liangmin +1 位作者 HOU Jin ZHAO Xia 《Journal of Ocean University of China》 SCIE CAS CSCD 2023年第3期728-734,共7页
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
关键词 antibacterial activity silver oxide nanoparticles carboxymethyl starch
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Antioxidant,Anti-inflammatory,and Antibacterial Activities of Different Extracts from Polygonum capitatum
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作者 Bo TU Minghui HE +2 位作者 Yitong SHEN Xu ZHANG Yan LIN 《Medicinal Plant》 CAS 2023年第2期15-18,共4页
[Objectives]To investigate the antioxidant,anti-inflammatory and antibacterial activities of different extracts(aqueous,ethanol,ethyl acetate and n-butanol extracts)of Miao medicine Polygonum capitatum.[Methods]Eleven... [Objectives]To investigate the antioxidant,anti-inflammatory and antibacterial activities of different extracts(aqueous,ethanol,ethyl acetate and n-butanol extracts)of Miao medicine Polygonum capitatum.[Methods]Eleven batches of P.capitatum in Guizhou province were collected,and water,ethanol,ethyl acetate and n-butanol extracts were prepared by reflux extraction.Antioxidant activity was determined by radical scavenging capacity of 1,1 diphenyl-2-picyl hydrazine(DPPH),anti-inflammatory activity was screened by lipopolysaccharide(LPS)induced RAW264.7 cells to produce NO,and the minimum inhibitory concentration(MIC)was screened by broth microdilution method.[Results]When the concentration of ethyl acetate extract was 10 mg/L,the scavenging rate of DPPH ranged from 90%to 99%.The(MIC of the ethyl acetate extract against Staphylococcus aureus(SA),Pseudomonas aeruginosa(PA)and Escherichia coli(EC)was 0.18-0.65,0.13-0.82,and 0.15-0.78 g/L,respectively.In the anti-inflammatory activity,ethyl acetate extract inhibited NO production with inhibition rate of 70%.[Conclusions]The ethyl acetate extract and ethanol extract of Miao medicine P.capitatum have strong antioxidant,anti-inflammatory and antibacterial activities. 展开更多
关键词 Chinese herbal medicine Polygonum capitatum EXTRACT active site Antioxidant activity Anti-inflammatory activity antibacterial activity
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Analysis on Antibacterial, Detumescent and Antioxidant Activity of Huoshan Large-leaf Yellow Tea
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作者 Jinwu CHEN Wen HU +4 位作者 Yimeng LI Jiaojiao WANG Yafei LIU Yi LI Lulu QI 《Medicinal Plant》 CAS 2023年第4期1-5,共5页
[Objectives] To provide experimental basis for the effective development and utilization of Huoshan large-leaf yellow tea resources and the screening of safe and effective active ingredients of large-leaf yellow tea. ... [Objectives] To provide experimental basis for the effective development and utilization of Huoshan large-leaf yellow tea resources and the screening of safe and effective active ingredients of large-leaf yellow tea. [Methods] The active substances of Huoshan large-leaf yellow tea were extracted by hot-water extraction, and the freeze-dried powder of Huoshan large-leaf yellow tea was obtained by freeze drying. The antibacterial activity of the extract was preliminarily confirmed using the Oxford cup method, and its antimicrobial spectrum was analyzed using 14 strains. A xylene-induced mouse auricle swelling test was carried out to detect the swelling inhibition rate of the extract and analyze its in-vitro detumescent activity. Then, the antioxidant activity of the extract was identified through a DPPH free radical scavenging capacity test and a ferric reducing antioxidant power assay. [Results] The extract had significant inhibitory effects on various bacteria. The extract could effectively inhibit the growth of Escherichia coli, Staphylococcus aureus, Enterococcus hirae, Acinetobacter baumannii, Klebsiella pneumonia, Pseudomonas aeruginosa, Bacillus subtilis , and other strains. The diameter of the inhibition zone increased with the increase of sample concentration. The extract had a significant inhibitory effect on auricle swelling induced by xylene in mice. When the concentration of the drug reached 1.0 mg/mL, its inhibition rate on mouse auricle swelling reached 55.2% ( P <0.01), slightly lower than the swelling inhibition rate of the aspirin group (66.52%, P <0.01). The results of the antioxidant test showed that large-leaf yellow tea extract also had strong activity. Within the concentration range of 0.1-1.0 mg/mL, its DPPH radical scavenging rate increased with the increase of sample concentration. Within the concentration range of 0.1-1.0 mg/mL, its DPPH radical scavenging rate increased with the increase of sample concentration. When the concentration reached 1.0 mg/mL, the scavenging rate reached 69.75%. The Fe 3+ -reduction capacity of the extract also increased with the increase of sample concentration within the concentration range of 0.1-2.5 mg/mL. When the concentration was 2.5 mg/mL, the reducing power of the extract reached 1.43±0.04. However, its DPPH free radical scavenging rate and reducing power were slightly lower than the capacity of V C at the same concentration. [Conclusions] The extract of Huoshan large-leaf yellow tea obtained by hot-water extraction had strong activity in many aspects, including inhibiting the growth of various microbes, subsiding swelling in vitro and resisting oxidation. These experimental results provide certain guiding significance for the basic research of Huoshan large-leaf yellow tea extract, as well as experimental data support for the subsequent development of functional foods and drugs of Huoshan large-leaf yellow tea. 展开更多
关键词 Huoshan large-leaf yellow tea antibacterial activity DETUMESCENCE Antioxidant activity
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Green Synthesis and Antibacterial Properties of Silver Nanoparticles from Eugenia uniflora Fruit Extract
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作者 Melissa Moya Vanessa Bagnarello +1 位作者 Julio Mora Idalia Valerio 《Advances in Nanoparticles》 2023年第3期94-105,共12页
The synthesis of nanoparticles by biological methods using microorganisms, enzymes, or plant extracts has been suggested as a possible ecofriendly alternative to chemical and physical methods that involve the use of h... The synthesis of nanoparticles by biological methods using microorganisms, enzymes, or plant extracts has been suggested as a possible ecofriendly alternative to chemical and physical methods that involve the use of harmful reducing agents. Green synthesis of silver nanoparticles (AgNPs) was achieved using Eugenia uniflora ripe fruit extract, which was characterized by phytochemical screening revealing the presence of polyphenols (quinones, flavonoids, and tannins), reducing compounds, and terpenes. These excellent antioxidants reduced silver nitrate to give the AgNPs, which were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), and ζ potential analysis. The diameter of the AgNPs ranged from 10.56 ± 1.2 nm to 107.56 ± 5.7 nm. The antibacterial activity of the AgNPs was evaluated using a modification of the Kirby-Bauer technique with Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. The inhibition halos were 11.12 ± 0.02 mm, 13.96 ± 0.07 mm, and 11.29 ± 0.76 mm, respectively. The synthesis using E. uniflora is an ecofriendly and low cost method of obtaining silver nanoparticles that could be used in health sciences because of their activity against bacteria with antibiotic resistance. 展开更多
关键词 Eugenia uniflora Green Synthesis Silver Nanoparticles antibacterial Activity POLYPHENOLS
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Synthesis of Al2S3/MoS2 Nanocomposite by Electrochemical Method: Correlation for Photodegradation of Trichloroacetic Acid, Chloroacetic Acid, Acetic Acid and Study of Antibacterial Efficiency
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作者 Hiremarali Sathyanarayana Sindhushree Kodenakoppalu Mahadevappa Chaithra +1 位作者 Rayapura Thimmegowda Radhika Bellale Marigowda Venkatesha 《Modern Research in Catalysis》 2023年第1期1-24,共24页
Al<sub>2</sub>S<sub>3</sub>/MoS<sub>2</sub> nanocomposite has been synthesized through electrochemical method and characterized by UV-Visible spectroscopy, XRD, SEM and EDAX data. U... Al<sub>2</sub>S<sub>3</sub>/MoS<sub>2</sub> nanocomposite has been synthesized through electrochemical method and characterized by UV-Visible spectroscopy, XRD, SEM and EDAX data. UV-Visible spectroscopy measurements reveal that the Al<sub>2</sub>S<sub>3</sub>/MoS<sub>2</sub> nanocomposite has maximum absorption at 353.04 nm and this peak position reflects the band gap of particles and it is found to be 2.51 eV which was calculated using Tauc plot. X-Ray diffraction (XRD) reveals crystaline size to be 49.85 nm which was calculated using Williamson-Hall (W-H) plot method. Photocatalytic degradation of acetic acid, chloroacetic acid and trichloroacetic acid has been studied by volumetric method using NaOH solution. Photocatalytic degradation of chloroacetic acid and acetic acid follows first order kinetics. The photodegradation efficiency for Al<sub>2</sub>S<sub>3</sub>/MoS<sub>2</sub> nanocomposite was found to be ≈97.8%. A Taft linear free energy relationship is noted for the catalysed reaction with ρ* = 0.233 and indicating electron withdrawing groups enhance the rate. An isokinetic relation is observed with β = 358 K indicating that enthalpy factor controls the reaction rate. The result of this paper suggests the possibility of degradation of organic compounds, industrial effluants and toxic organic compounds by photodegradation process by ecofriendly Al<sub>2</sub>S<sub>3</sub>/ MoS<sub>2</sub>. The antibacterial activity of Al<sub>2</sub>S<sub>3</sub>/MoS<sub>2</sub> nanocomposite was investigated. These particles were shown to have an effective bactericide. 展开更多
关键词 Electrochemical Method Al2S3/MoS2 Nanoparticles Carboxylic Acids LFER antibacterial Activity
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Discovery and structure-activity relationship studies of novel tetrahydro-β-carboline derivatives as apoptosis initiators for treating bacterial infections
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作者 Shanshan Su Hongwu Liu +7 位作者 Junrong Zhang Puying Qi Yue Ding Ling Zhang Linli Yang Liwei Liu Xiang Zhou Song Yang 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第4期1259-1273,共15页
Developing and excavating new agrochemicals with highly active and safe is an important tactic for protecting crop health and food safety.In this paper,to discover the new bactericide candidates,we designed,prepared a... Developing and excavating new agrochemicals with highly active and safe is an important tactic for protecting crop health and food safety.In this paper,to discover the new bactericide candidates,we designed,prepared a new type of1,2,3,4-tetrahydro-β-carboline(THC)derivatives and evaluated the in vitro and in vivo bioactivities against the Xanthomonas oryzae pv.oryzae(Xoo),Xanthomonas axonopodis pv.citri(Xac),and Pseudomonas syringae pv.actinidiae(Psa).The in vitro bioassay results exhibited that most title molecules possessed good activity toward the three plant pathogenic bacteria,the compound A17 showed the most active against Xoo and Xac with EC50 values of 7.27 and 4.89 mg mL^(-1)respectively,and compound A8 exhibited the best inhibitory activity against Psa with EC50value of 4.87 mg mL^(-1).Pot experiments showed that compound A17 exhibited excellent in vivo antibacterial activities to manage rice bacterial leaf blight and citrus bacterial canker,with protective efficiencies of 52.67 and 79.79%at 200 mgmL^(-1),respectively.Meanwhile,compound A8 showed good control efficiency(84.31%)against kiwifruit bacterial canker at 200 mg mL^(-1).Antibacterial mechanism suggested that these compounds could interfere with the balance of the redox system,damage the cell membrane,and induce the apoptosis of Xoo cells.Taken together,our study revealed that tetrahydro-β-carboline derivatives could be a promising candidate model for novel broadspectrum bactericides. 展开更多
关键词 tetrahydro-β-carboline derivatives antibacterial activity ROS cell apoptosis
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Green Synthesis of Silver Nanoparticles Using Aqueous Orange and Lemon Peel Extract and Evaluation of Their Antimicrobial Properties
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作者 Amra Bratovcic Amna Dautovic 《Advances in Nanoparticles》 CAS 2024年第2期11-28,共18页
Green synthesis of silver nanoparticles (AgNPs) using aqueous extracts of orange and lemon peels, as a reducing agent, and silver nitrate salts as a source of silver ions is a promising field of research due to the ve... Green synthesis of silver nanoparticles (AgNPs) using aqueous extracts of orange and lemon peels, as a reducing agent, and silver nitrate salts as a source of silver ions is a promising field of research due to the versatility of biomedical applications of metal nanoparticles. In this paper, AgNPs were synthetized at different reaction parameters such as the type and concentration of the extracts, metal salt concentration, temperature, speed stirring, and pH. The antibacterial properties of the obtained silver nanoparticles against E. coli, as well as the physical and chemical characteristics of the synthesized silver nanoparticles, were investigated. UV-Vis spectroscopy was used to confirm the formation of AgNPs. In addition to green biogenic synthesis, chemical synthesis of silver nanoparticles was also carried out. The optimal temperature for extraction was 65˚C, while for the synthesis of AgNPs was 35˚C. The synthesis is carried out in an acidic environment (pH = 4.7 orange and pH = 3.8 lemon), neutral (pH = 7) and alkaline (pH = 10), then for different concentrations of silver nitrate solution (0.5 mM - 1 mM), optimal time duration of the reaction was 60 min and optimal stirring speed rotation was 250 rpm on the magnetic stirrer. The physical properties of the synthesized silver nanoparticles (conductivity, density and refractive index) were also studied, and the passage of laser light through the obtained solution and distilled water was compared. Positive inhibitory effect on the growth of new Escherichia coli colonies have shown AgNPs synthesized at a basic pH value and at a 0.1 mM AgNO<sub>3</sub> using orange or lemon peel extract, while for a 0.5 mM AgNO<sub>3 </sub>using lemon peel extract. 展开更多
关键词 Green Synthesis Silver Nanoparticles Orange and Lemon Peel Extract antibacterial Activity Escherichia coli
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Isolation and Experimental Study on Bacteriostasis of Bacillus haynesii
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作者 Jiedan Liao Mengbo Yu +4 位作者 Jiaming Li Zhiheng Xie Wanjun Gu Shuzhen Zhou Yi Ma 《Journal of Clinical and Nursing Research》 2024年第7期219-227,共9页
This experiment aims to isolate and inhibit three bacteria strains to provide candidate strains for the development and application of probiotics.Using bacterial morphological identification,16S rDNA sequence alignmen... This experiment aims to isolate and inhibit three bacteria strains to provide candidate strains for the development and application of probiotics.Using bacterial morphological identification,16S rDNA sequence alignment,and genetic evolution analysis,three strains were identified as Bacillus haynesii,named HP01,HD02,and HK03.Through biosurfactant activity tests,C-TAB tests,hemolysis tests,and antibacterial activity analyses,the results showed that all three strains of B.haynesii exhibited significant biosurfactant activity.Additionally,the solutions of the three strains demonstrated a pronounced antibacterial effect on Staphylococcus aureus.The resistance and safety of commonly used drugs were evaluated using the tablet diffusion method and a mouse feeding test.The results indicated that the three strains were not resistant to commonly used antibacterial drugs,and the oral bacterial solution was not pathogenic and had high safety in mice.The study concluded that all three B.haynesii strains met the basic conditions for use,with B.haynesii HP01 being the most promising candidate. 展开更多
关键词 Bacillus haynesii Separation identification antibacterial activity Safety
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Phytochemical Characterization and Evaluation of the Antibacterial Activity of Leaf Extracts of Mitragyna inermis (Willd.) O. Ktze on the in Vitro Growth of Clinical Strains Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa Involved in Gastro Enteritis
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作者 Monon Kone Youssouf Zanga Traore +4 位作者 Tidiane Kamagate Ahmont Landry Claude Kablan Abdoulaye Toure Karamoko Ouattara Adama Coulibaly 《Journal of Biosciences and Medicines》 2024年第6期101-113,共13页
Gastroenteritis constitutes a group of diarrheal diseases of infectious origin, responsible for absenteeism from work, morbidity and mortality, especially among aged people. This study aimed to evaluate the antibacter... Gastroenteritis constitutes a group of diarrheal diseases of infectious origin, responsible for absenteeism from work, morbidity and mortality, especially among aged people. This study aimed to evaluate the antibacterial activity of Mitragyna inermis extracts on the in vitro growth of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa involved in gastroenteritis. Phytochemical screening was carried out using two distinct methods. The detection of phytochemical compounds by tube coloring and chromatography on a thin layer of silica gel. The sensitivity of organisms was evaluated by the agar well method. The dilution method in liquid medium coupled with spreading on Mueller Hinton agar helped determine the CMB/MIC activity ratios. The investigations show that the extract has the best extraction yield (75.86% ± 0.20%) compared to the aqueous macerated (61.8% ± 0.08%) and decocted (66.6% ± 0.12%). These extracts contain several phytochemical compounds such as flavonoids, polyphenols, tannins, alkaloids, saponosides, coumarins and sterols and terpenes. These substances are endowed with biological activities and could be at the origin of antibacterial activity observed with M. inermis extracts. The analysis of antibacterial activity showed that the germs are sensitive to the extracts with inhibition diameters ranging from 8.30 ± 0.53 to 17.87 ± 0.58 mm. The ethanolic extract was the most active with diameters varying from 15.07 ± 0.62 to 17.87 ± 0.58 mm on all the germs tested. E. coli and S. aureus were the most sensitive germs to the extracts. P. aeruginosa was the least sensitive germ. Activity reports indicate that the extracts exert bactericidal activity on E. coli and S. aureus but bacteriostatic activity on P. aeruginosa. These results justify the use of M. inermis leaves in a traditional environment to treat gastroenteritis. 展开更多
关键词 Phytochemical Characterization antibacterial Activity Mitragyna inermis Gastro Enteritis
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Review on Zinc Oxide Nanoparticles: Antibacterial Activity and Toxicity Mechanism 被引量:84
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作者 Amna Sirelkhatim Shahrom Mahmud +5 位作者 Azman Seeni Noor Haida Mohamad Kaus Ling Chuo Ann Siti Khadijah Mohd Bakhori Habsah Hasan Dasmawati Mohamad 《Nano-Micro Letters》 SCIE EI CAS 2015年第3期219-242,共24页
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
关键词 antibacterial activity Zn O-NPs Toxicity mechanism Reactive oxygen species Zinc ions release Food antimicrobial
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Synthesis,Characterization and Antibacterial Properties of Rare Earth (Ce^(3+) ,Pr^(3+) ,Nd^(3+) ,Sm^(3+) ,Er^(3+) ) Complexes with L-Aspartic Acid and o-Phenanthroline 被引量:15
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作者 郁慧 何其庄 +1 位作者 杨静 郑文捷 《Journal of Rare Earths》 SCIE EI CAS CSCD 2006年第z2期4-8,共5页
Five novel ternary complexes of rare earth ions with L-Aspartic acid (Asp) and o-phenanthroline (Phen) were synthesized in ethanol aqueous solution. Their compositions were characterized by elemental analysis, molar c... Five novel ternary complexes of rare earth ions with L-Aspartic acid (Asp) and o-phenanthroline (Phen) were synthesized in ethanol aqueous solution. Their compositions were characterized by elemental analysis, molar conductance, FT-IR, Raman, UV-VIS and TG-DTA. The compositions of the complexes were confirmed to be: RE( Asp)3PhenCl3·3H2O (RE: Ce3+ , Pr3+ , Nd3+ , Sm3+ , Er3+ ). The antibacterial activity test shows that all these complexes exhibit excellent antibacterial ability against Escherichia coli, Staphylococcus aureus and Candida albicans. The antimicrobial spectrum of the complexes are broad. 展开更多
关键词 COMPLEXES O-PHENANTHROLINE L-Aspartic acid antibacterial activity rare earths
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In vitro antibacterial and free radical scavenging activity of green hull of Juglans regia 被引量:6
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作者 Pardeep Sharma G.Ravikumar +2 位作者 M.Kalaiselvi D.Gomathi C.Uman 《Journal of Pharmaceutical Analysis》 SCIE CAS 2013年第4期298-302,共5页
Abstract Antioxidant supplements from plants are vital to count the oxidative damage in cells. We assessed the antioxidants and antibacterial activity of green hull of Juglans regia in this study. According to our res... Abstract Antioxidant supplements from plants are vital to count the oxidative damage in cells. We assessed the antioxidants and antibacterial activity of green hull of Juglans regia in this study. According to our results the maximum antibacterial activity was observed in ethanolic extract when compared to other extract. So, the ethanolic extract was studied for antioxidant activity which exhibited high antiradical activity against DPPH, hydroxyl, and nitric oxide radicals. In conclusion, green hull of J. regia showed strong reducing power activity and total antioxidant capacity. The results justify the therapeutic application of plant in the indigenous system of medicine. 展开更多
关键词 Juglans regia Ethanolic extract ANTIOXIDANTS DPPH antibacterial activity
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Synthesis and evaluation of in vitro antibacterial activity of novel 2,5-disubstituted-l,3,4-thiadiazoles from fatty acids 被引量:7
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作者 Mudasir R.Banday Abdul Rauf 《Chinese Chemical Letters》 SCIE CAS CSCD 2008年第12期1427-1430,共4页
A series of new 1-(alkenoyl/hydroxyalkenoyl)-4-benzoyl-thiosemicarbazides 2a-d and 2-benzamide-5-alkenyl/hydroxyalk- enyl-1,3,4-thiadiazoles 3a-d were synthesized from fatty acid hydrazides. Structure of all these c... A series of new 1-(alkenoyl/hydroxyalkenoyl)-4-benzoyl-thiosemicarbazides 2a-d and 2-benzamide-5-alkenyl/hydroxyalk- enyl-1,3,4-thiadiazoles 3a-d were synthesized from fatty acid hydrazides. Structure of all these compounds was confirmed by IR, IH NMR, Sac NMR, mass spectra and elemental analysis. The bioassay results indicate that some compounds 2e, 2d, 3e and 3d have good antibacterial activity. 展开更多
关键词 Aroylthiosemicarbazide 1 3 4-THIADIAZOLE antibacterial activity
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