纳米银/植物源复合抗菌剂的制备及其抑菌性能的研究

以硝酸银作为银源,水溶性淀粉作保护剂,丙酮酸钠作还原剂,氨水提供碱性环境来制备纳米银胶,并以聚乙烯吡咯烷酮(PVP)作分散稳定剂,复配红景天提取液和无患子提取液制备出纳米银/植物源复合抗菌剂。实验结果表明,纳米银胶或植物提取液仅对部分细菌或霉菌有较强抑制效果,而复合抗菌剂对细菌、霉菌均有很强抑制效果。在湿巾液中添加0.5%复合抗菌剂时,其对大肠杆菌,金黄色葡萄球菌和白色念珠菌的抗菌效率可达99%,且经过常温六个月、高温55℃一个月保存后,其抗菌活性分别可达到95%、90%左右,表明复合抗菌剂具有较强的抗菌效率及抗菌稳定性。     

Bactericidal effect of a silica gel-supported porphyrinatoantimony(V) complex under visible light irradiation

In order to develop a bactericidal agent operating under visible light irradiation, a silica gel-supported dihydroxo(tetraphenylporphyrinato)antimony(V) complex (SbTPP/SiO₂) was prepared. The SbTPP/SiO₂ particles irradiated by fluorescent light in a test tube induced remarkable bactericidal activity for Escherichia coli cells. The bactericidal activity of the SbTPP/SiO₂ was affected by both the concentration of the SbTPP/SiO₂ and the light intensity. Under irradiation by visible light, the SbTPP/SiO₂ photocatalyst showed much superior bactericidal activity to the commercially available TiO₂. Moreover, under irradiation by sunlight, bactericidal activity of the SbTPP/SiO₂ was observed, and the bactericidal effect of the SbTPP/SiO₂ particles was effective for continuous treatment on a column photoreactor under fluorescent-light irradiation.     

纳米银胶/壳聚糖复合抗菌剂的制备及其在洗涤产品中抗菌性能

本文研究了纳米银胶/壳聚糖抗菌剂的制备及其形貌的表征分析,以大肠杆菌为代表菌株,研究了复合抗菌剂在洗涤产品中的抗菌效率及抗菌的稳定性,结果说明复合抗菌剂在洗涤产品中添加1.0%时,其抗菌效率达99%,经180 d长期分析,其抗菌活性仍保持95%左右。此外,复合抗菌剂对不同菌株的抗菌性能也均较强。     

Photocatalytic antibacterial effects on TiO2-anatase upon UV-A and UV-A/VIS threshold irradiation

Photocatalysis mediated by the anatase modification of titanium dioxide (TiO₂) has shown antibacterial effects in medical applications. The aim of this study was to investigate the possibility of expanding the excitation wavelengths for photocatalytic antibacterial effects from ultraviolet (UV) into the visible light range. After deposition of salivary pellicle and adhesion of Streptococcus gordonii on anatase, different irradiation protocols were applied to induce photocatalysis: ultraviolet A (UV-A) > 320 nm; ultraviolet/visible (UV-A/VIS) light > 380 nm and > 390 nm; and VIS light 400–410 nm. A quartz crystal microbalance with dissipation (QCM-D) tests and microscopic examination were used to observe the photoinduced antibacterial effects. Salivary pellicle could be photocatalytically decomposed under all irradiation protocols. In contrast, effective photocatalytic attack of bacteria could be observed by UV-A as well as by UV-A/VIS at 380 nm < λ < 390 nm only. Wavelengths above 380 nm show promise for in situ therapeutic antifouling applications.     

New synthesis of a porous Si/TiO2 photocatalyst: testing its efficiency and stability under visible light irradiation.

TiO(2) nanoparticles were directly coupled with porous silicon and this novel composite material shows very strong photocatalytic activity for the degradation of Rhodamine B with high photochemical stability under visible light irradiation.     

Synthesis and antibacterial activity of a new series of 3-[3-(substituted phenyl)-1-phenyl-1H-pyrazol-5-yl]-2H-chromen-2-one derivatives

A series of 3-[3-(substituted phenyl)-1-phenyl-1H-pyrazol-5-yl]-2H-chromen-2-one (4a–k) were synthesized by reaction of 3-[2,3-dibromo-3-(substituted phenyl)propanoyl]-2H-chromen-2-one (3 a-k) with phenyl hydrazine in presence of triethylamine in absolute ethanol, characterized by spectral data and screened for their in vitro antibacterial activity against gram-positive and gram-negative bacteria. Among the series, compounds 4d, 4h and 4i displayed an encouraging antibacterial activity profile as compared to reference standard drug ciprofloxacin against tested bacterial strains.     

一株海洋真菌Aspergillus jensenii LW128的次级代谢产物及其抗菌活性研究

【目的】研究一株西北太平洋深海沉积物来源真菌Aspergillus jensenii LW128的次级代谢产物及其抗菌活性。【方法】利用硅胶柱色谱(silica gel column chromatography)、凝胶柱色谱(Sephadex LH-20 column chromatography)和反相高效液相色谱(reversed-phase high-performance liquid chromatography, RP-HPLC)等方法对菌株的发酵粗提物进行分离纯化得到单体化合物;将核磁共振波谱(nuclear magnetic resonance, NMR)、质谱(mass spectrometry, MS)数据与相关文献报道数据进行比对后确定化合物结构;采用肉汤微量稀释法测定化合物的抗菌活性。【结果】从海洋真菌Aspergillus jensenii LW128中分离并鉴定了10个已知化合物,分别为diorcinol D(1)、diorcinol K(2)、diorcinol I(3)、(+)-(7S)-7-O-methylsydonic acid (4)、(+)-s...     

植物乳杆菌DY6主要抑菌代谢物的分析和鉴定

【背景】被广泛应用于食品和饲料等多个行业的乳酸菌已成为制作生物防腐剂的研究热点。【目的】探究抑菌性能良好的植物乳杆菌DY6的抑菌物质,为其进一步应用提供参考依据。【方法】对植物乳杆菌发酵液中抑菌物质的理化特性进行研究,采用GC-MS分析发酵上清液代谢物,通过多元统计学分析方法推测主要抑菌物质,抑菌物质通过半制备进行初步分离后用GC-MS鉴定。【结果】植物乳杆菌DY6对金黄色葡萄球菌、大肠杆菌、沙门氏菌都有较强的抑制作用。采用不同发酵时间的发酵液作为研究对象,测定发酵上清液的抑菌能力,发酵0-4 h上清液无抑菌能力,发酵至8 h抑菌能力逐步上升,发酵24-48 h发酵上清液抑菌能力趋于稳定,在48 h时抑菌能力最佳,抑菌直径为15.28mm。通过多元统计学分析乳酸菌发酵液差异标志物,发现主要差异物为有机酸(如乳酸、乙酸、丙酸等)和脂肪酸(如辛酸、癸酸等)。经过半制备液相分离发酵上清液得到的抑菌组分,主要有有机酸(如乳酸、乙酸、3-苯基乳酸、苯丙酸等)和脂肪酸(如癸酸、辛酸、壬酸等),另外还有少量的醛类和醇类物质。【结论】确定了植物乳杆菌DY6的抑菌物质主要为有机酸和脂肪酸,为其进一步防腐应用提供了理论基础。     

Synthesis of fluorescent and low cytotoxicity phenol formaldehyde resin (PFR)@Ag composites for cell imaging and antibacterial activity

Ag nanoparticles (NPs) were loaded onto the surface of phenol formaldehyde resin (PFR) NPs without any reducing agent. The as‐synthesized PFR@Ag composites have low cytotoxicity, which makes them promising antibacterial agents. Furthermore, the good fluorescence of PFR could be used for cell imaging. Copyright © 2015 John Wiley & Sons, Ltd.     

毛咀地星的抗氧化、抗菌和抗肿瘤活性和化学成分研究

毛咀地星是一种药用蘑菇,为了进一步开发利用毛咀地星,该研究探讨了毛咀地星乙醇提取物的抗氧化、抗菌和抗肿瘤活性,并采用硅胶柱色谱、制备薄层色谱和重结晶等方法,对毛咀地星乙醇提取物进行分离纯化,研究了其化学成分。结果表明:毛咀地星乙醇提取物多酚含量为10.53μg·mg~(-1),DPPH和·OH自由基清除能力的IC50值分别为91.35和148.76μg·m L~(-1);乙醇提取物对金黄葡萄球菌、大肠杆菌和枯草芽抱杆菌均无抑制作用;乙醇提取物在浓度为1 mg·m L~(-1)时,对燕麦镰刀菌的抑制率为36.11%;乙醇提取物在浓度为200μg·m L~(-1)时,对BG-803、NCI-H502和MDA-MB-231肿瘤细胞的抑制率分别为18.87%、17.71%和41.23%。并从乙醇提取物中分离纯化到6个化合物,根据理化性质和波谱数据分析,化合物结构分别鉴定为5α,8α-过氧化麦角甾-6,9(11),22-三烯-3β-醇(1)、5α,8α-过氧化麦角甾-6,22-二烯-3β-醇(2)、D-阿拉伯糖醇(3)、L-谷氨酸(4)、麦芽糖(5)和蔗糖(6),以上化合物均为首次从该菌中分离得到。     

Synthesis and antibacterial properties of new N4-acetylated hexahydro-2,7-dioxopyrido[2,3-f]quinoxaline-8-carboxylic acids

Direct interaction between 7-chloro-1-cyclopropyl-6-fluoro-8-nitro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid and primary α-amino acids (exemplified by glycine, alanine, and l-valine) in aqueous ethanolic NaHCO₃ at 70–80°C for 24–72?h produced the respective N-(4-oxoquinolin-7-yl)-α-amino acids (6a–c). The latter derivatives underwent reductive lactamization upon treatment with Na₂S₂O₄ in aqueous ethanol to afford moderate yields of the corresponding pyrido[2,3-f]quinoxaline-8-carboxylic acids (8a–c). Acetylation of 8a–c using acetyl chloride afforded N₄-acetylated hexahydro-2,7-dioxopyrido[2,3-f]quinoxaline-8-carboxylic acids (9a–c). The structures, assigned to these new heterocyclic products, are supported by analytical and spectral data. The synthesized compounds (6a–c/9a–c) showed appreciable antibacterial activity as compared with ciprofloxacin.     

In vitro antibacterial and cytotoxic activities of carvacrol and terpinen-4-ol against biofilm formation on titanium implant surfaces

Abstract

This study evaluated the antibacterial properties of carvacrol and terpinen-4-ol against Porphyromonas gingivalis and Fusobacterium nucleatum and its cytotoxic effects on fibroblast cells. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were examined. The minimum biofilm inhibition concentration (MBIC) was evaluated by XTT assay. Biofilm decontamination on titanium surfaces was quantified (CFU ml^?1), evaluated by confocal laser scanning microscopy (CLSM) and cytotoxic activity by MTT. The MIC and MBC for carvacrol were 0.007% and 0.002% for P. gingivalis and F. nucleatum, and 0.06% for terpinen-4-ol for both microorganisms. The MBIC for carvacrol was 0.03% and 0.06% for P. gingivalis and F. nucleatum, and for terpinen-4-ol was 0.06% and 0.24%. The results indicated anti-biofilm activity using carvacrol (0.26%, 0.06%) and terpinen-4-ol (0.95%, 0.24%) and showed cytotoxic activity similar to chlorohexidine (CHX). However, terpinen-4-ol (0.24%) showed higher cell viability than other treatments. Carvacrol and terpinen-4-ol showed antibacterial activity in respect of reducing biofilms. Moreover, CHX-like cytotoxicity was observed.     

In vitro antibacterial activity and physicochemical properties of a crude methanol extract of the larvae of the blow fly Lucilia cuprina

The emergence of multidrug‐resistant bacterial strains has prompted the reintroduction of maggot therapy in the treatment of chronic, infected wounds. Many previous studies have demonstrated the potent antibacterial activity of larval excretions/secretions of the blowfly Lucilia sericata (Meigen) (Diptera:Calliphoridae) against bacteria. However, the antibacterial activity of its sibling species, Lucilia cuprina (Wiedemann) (Diptera:Calliphoridae) against a wide range of pathogenic bacteria has never been determined. The aim of this study was to develop a new procedure to produce whole body extract of larvae of L. cuprina via methanol extraction as well as to demonstrate the in vitro antibacterial activity of this extract against seven selected wound pathogens (Staphylococcus aureus, methicillin‐resistant S. aureus, S. epidermidis, Streptococcus pyogenes, Klebsiella pneumoniae, Pseudomonas aeruginosa and Escherichia coli). The turbidimetric assay demonstrated that L. cuprina larval extract was significantly potent against all bacteria tested (P < 0.001). Additionally, colony‐forming unit (CFU), agar well diffusion and minimum inhibitory concentration assays have confirmed the apparent potency of larval extract against P. aeruginosa. The reconstituted larval extract was highly robust and thermally stable. These observations substantiated the feasibility of the methanol extraction method in the production of larval extract.     

Synthesis,spectral characterization,and in vitro antibacterial and antifungal activities of novel 1,3-thiazine-2-amines comprising morpholine nucleus

A collection of 4-(4-morpholinophenyl)-6-aryl-6H-1,3-thiazin-2-amines (20–28) were synthesized and their in vitro antimicrobial activity was investigated. Compound 21 against P. aeruginosa, 23 against B. subtilis, 24 against V. cholerae and P. aeruginosa, 26 against S. aureus and B. subtilis, 27 against B. subtilis and E. coli, and 28 against all tested bacterial strains exerted excellent antibacterial activity. Compound 20 against A. flavus and Rhizopus, 21, 26 against Rhizopus, 22, 27 against Mucor, 23 against A. flavus, 24 against both A. flavus and Mucor, 25 against all tested strains, and 28 against Rhizopus and M. gypseum exerted excellent antifungal activity.     

北桑寄生产黄酮内生菌的分离鉴定及其抗氧化和抑菌活性评价

【背景】北桑寄生(Loranthus tanakae)植物中黄酮类化合物成分含量较高,生物活性较好。由于植物资源短缺,导致其生物活性成分的研究受限。【目的】从北桑寄生中分离、筛选和鉴定产黄酮类化合物的内生菌,并评估其体外抗氧化和抑菌活性。【方法】以北桑寄生枝条为研究对象分离内生菌,通过显色反应和薄层色谱法(thin-layer chromatography,TLC)筛选产黄酮类化合物的内生菌,并采用NaNO₂-Al (NO₃)₃比色法测定其总黄酮含量。利用清除自由基和抑菌的体外实验来初步评估产黄酮内生菌的生物活性。【结果】共筛选出4株产黄酮内生菌,其中3株为内生真菌,1株为内生细菌,通过形态学和分子生物学方法将其分别鉴定为Botryosphaeria sp.(ZC020)、Phoma sp.(ZZ105)、Nemania sp.(ZS042)和Pseudomonas sp.(ZC026)。4株菌中ZC020和ZS042的总黄酮含量较高,分别为(44.58±0.72) mg/L和(31.98±0.18) mg/L (P<0.05,n=3),并且ZS042可产生与北桑寄生植物相同类型的黄酮类化合物。ZC026和ZS042表现出优异的抗氧化活性,其1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)和2,2''-联氮-二(3-乙基苯并噻唑啉-6-磺酸)二铵盐[2,2''-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt,ABTS]自由基清除率分别为72.85%±0.66%(ZC026)、57.01%±0.89%(ZS042)和85.36%±0.75%(ZC026)、88.17%±0.15%(ZS042)(P<0.05,n=3)。ZZ105对革兰氏阳性菌和革兰氏阴性菌均有抑制作用。【结论】从北桑寄生枝条中分离出4株产黄酮类化合物的内生菌,其中有一株为内生细菌。这项工作为北桑寄生黄酮类化合物的生产提供了新的资源,也为其他珍稀药用植物和材料的开发和保护提供了参考。     

九香虫血淋巴及其纯化蛋白抑菌活性的研究

对九香虫AsporgopuschinensisDallas血淋巴及其血淋巴蛋白质分离物的抗菌活性进行了研究,抗菌活性检测指示菌为大肠杆菌Escherichiacoli和金黄色葡萄球菌Staphilocalliesacereus。测定结果表明,九香虫血淋巴及其离心上清液都具有明显的抗菌活性。用凝胶过滤法从血淋巴蛋白分离提纯获得一种小分子肽,SDS PAGE电泳为单一带,分子量约为1～1 4 4kD。该小分子蛋白对大肠杆菌和金黄色葡萄球菌都有抑菌作用,与血淋巴对2种细菌的抗菌性一致,表明其是九香虫血淋巴中具抗菌作用的主要物质之一。     

Unexpected formation of 3-chloro-1-hydroxy-2,6-diarylpiperidin-4-ones: Synthesis,antibacterial and antifungal activities

New 3-chloro-1-hydroxy-2,6-diarylpiperidin-4-ones 18–22 were synthesized, characterized by melting point, elemental analysis, MS, FT-IR, one-dimensional NMR (¹H & ¹³C) spectroscopic data and evaluated for their in vitro antibacterial and antifungal activities. All the newly synthesized compounds exerted a wide range of antibacterial activities against the entire tested gram-positive and gram-negative bacterial strains except Escherichia coli. Compounds 21 and 22 exerted strong antifungal activities against Aspergillus flavus, mucor and Microsporum gypsuem. In addition, compound 20 was more potent against Rhizopus.