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Rohit K. Sharma Dr. Sandeep Sundriyal Dr. Nishima Wangoo Werner Tegge Dr. Rahul Jain Prof. 《ChemMedChem》2010,5(1):86-95
Synthetic antimicrobial peptides have recently emerged as promising candidates against drug‐resistant pathogens. We identified a novel hexapeptide, Orn‐D ‐Trp‐D ‐Phe‐Ile‐D ‐Phe‐His(1‐Bzl)‐NH2, which exhibits broad‐spectrum antifungal and antibacterial activity. A lead optimization was undertaken by conducting a full amino acid scan with various proteinogenic and non‐proteinogenic amino acids depending on the hydrophobic or positive‐charge character of residues at various positions along the sequence. The hexapeptide was also cyclized to study the correlation between the linear and cyclic structures and their respective antimicrobial activities. The synthesized peptides were found to be active against the fungus Candida albicans and Gram‐positive bacteria such as methicillin‐resistant Staphylococcus aureus and methicillin‐resistant Staphylococcus epidermidis, as well as the Gram‐negative bacterium Escherichia coli; MIC values for the most potent structures were in the range of 1–5 μg mL?1 (IC50 values in the range of 0.02–2 μg mL?1). Most of the synthesized peptides showed no cytotoxic effects in an MTT assay up to the highest test concentration of 200 μg mL?1. A tryptophan fluorescence quenching study was performed in the presence of negatively charged and zwitterionic model membranes, mimicking bacterial and mammalian membranes, respectively. The results of the fluorescence study demonstrate that the tested peptides are selective toward bacterial over mammalian cells; this is associated with a preferential interaction between the peptides and the negatively charged phospholipids of bacterial cells. 相似文献
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A series of novel cationic gemini surfactants [CnH2n+1–O–CH2–CH(OH)–CH2–N+(CH3)2–(CH2)2]2·2Br? [ 3a (n = 12), 3b (n = 14) and 3c (n = 16)] having a 2‐hydroxy‐1,3‐oxypropylene group [?CH2–CH(OH)–CH2–O–] in the hydrophobic chain have been synthesized and characterized. Their water solubility, surface activity, foaming properties, and antibacterial activity have been examined. The critical micelle concentration (CMC) values of the novel cationic gemini surfactants are one to two orders of magnitude smaller than those of the corresponding monomeric surfactants. Furthermore, the novel cationic gemini surfactants have better water solubility and surface activity than the comparable [CnH2n+1–N+(CH3)2–(CH2)2]2·2Br? (n‐4‐n) geminis. The novel cationic gemini surfactants 3a and 3b also exhibit good foaming properties and show good antibacterial and antifungal activities. 相似文献
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Nadia Ahmed Mohamed Mona Mohamed Fahmy 《International journal of molecular sciences》2012,13(9):11194-11209
Four novel hydrogels based on chitosan were synthesized via a cross-linking reaction of chitosan with different concentrations of oxalyl bis 4-(2,5-dioxo-2H-pyrrol- 1(5H)-yl)benzamide. Their structures were confirmed by fourier transform infrared X-ray (FTIR), scanning electron microscopy (SEM) and X-ray diffraction. The antimicrobial activities of the hydrogels against two crop-threatening pathogenic fungi namely: Aspergillus fumigatus (A. fumigatus, RCMBA 06002), and Aspergillus niger (A. niger, RCMBA 06106), and five bacterial species namely: Bacillis subtilis (B. subtilis, RCMBA 6005), Staphylococcus aureus (S. aureus, RCMBA 2004), Streptococcus pneumoniae (S. pneumonia, RCMB 000101) as Gram positive bacteria, and Salmonella typhimurium (S. typhimurium, RCMB 000104), and Escherichia coli (E. coli, RCMBA 5003) as Gram negative bacteria have been investigated. The prepared hydrogels showed much higher antimicrobial activities than that of the parent chitosan. The hydrogels were more potent in case of Gram-positive bacteria than Gram-negative bacteria. Increasing the degree of cross-linking in the hydrogels resulted in a weaker antimicrobial activity. 相似文献
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Forty‐three oxime derivatives were synthesized by allowing O‐benzylhydroxylamines to react with primary benzaldehydes or salicylaldehydes; these products were gauged as potential inhibitors of β‐ketoacyl‐(acyl‐carrier‐protein) synthase III (FabH). Among the 43 compounds, 38 are reported herein for the first time. These compounds were assayed for antimicrobial activities against Escherichia coli, Pseudomonas aeruginosa, Pseudomonas fluorescens, Bacillus subtilis, Staphylococcus aureus, and Enterococcus faecalis. Compounds with prominent antibacterial activities were tested for their E. coli FabH inhibitory activities. 3‐((2,4‐Dichlorobenzyloxyimino)methyl)benzaldehyde O‐2,4‐dichlorobenzyl oxime ( 44 ) showed the best antibacterial activity, with minimum inhibitory concentrations of 3.13–6.25 μg mL?1 against the tested bacterial strains, exhibiting the best E. coli FabH inhibitory activity, with an IC50 value of 1.7 mM . Docking simulations were performed to position compound 44 into the E. coli FabH active site in order to determine the most probable binding conformation. 相似文献
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以二茂铁、苯甲酸乙酯及水合肼为原料合成了乙酰二茂铁苯甲酰腙(AFZ),其结构通过IR、1 H NMR和元素分析予以确证,讨论了影响AFZ收率的三种因素;测定了AFZ无水乙腈溶液的循环伏安图和二甲亚砜溶液的抑菌活性。循环伏安实验表明,在扫描范围(-0.30~0.83V)内,AFZ出现了一对氧化还原峰;当扫描速度为100~500mV/s,其半波电位(E1/2)为0.514~0.538V;峰电流比(Ipa/Ipc)为1.605~1.630;峰电流(Ip)与扫描速度平方根(V1/2)呈良好的线性关系。抑菌试验表明,AFZ对大肠杆菌和金黄色葡萄球菌均有较好的抑菌活性。 相似文献
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Synthesis,Surface and Antimicrobial Activities of Cationic Gemini Surfactants with Semi-Rigid Spacers 下载免费PDF全文
Hai-lin Zhu Zhi-yong Hu Xue-mei Ma Jian-long Wang Duan-lin Cao 《Journal of surfactants and detergents》2016,19(2):265-274
Four cationic gemini surfactants featuring semi-rigid spacers were synthesized via a two-step process. The surface-active properties of these surfactants were investigated through surface tension and electrical conductivity measurement. The thermodynamic parameters of micellization were evaluated from electrical conductivity measurements at temperatures ranging from 293 to 313 K. The aggregation behavior of these synthesized gemini surfactants in water were investigated using dynamic light scattering and transmission electron microscopy. Further, the antimicrobial activities of these synthesized gemini surfactants against both Gram-positive and Gram-negative bacteria were also investigated. 相似文献
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Nabel A. Negm Ismail A. Aiad Salah M. Tawfik 《Journal of surfactants and detergents》2010,13(4):503-511
Eight novel uracil-based cationic surfactants containing Schiff base species were synthesized and characterized using elemental
analysis, FTIR, 1H-NMR and 13C-NMR spectroscopy. The surface activities of the synthesized Schiff bases and their cationic derivatives were determined
based on interfacial tension measurements and partition coefficient values in water/octanol system. The synthesized Schiff
bases and their cationic derivatives were evaluated as novel biocides against different bacteria and fungi strains. The results
showed that the biocidal activity of the synthesized Schiff bases was considerably increased by quaternization. The influence
of the cationic surfactants as biocides was increased by increasing the hydrophobic chain length and the presence of the methoxy
groups. The biocidal activity was also increased by increasing the partition coefficient in water/octanol system. The structure
and surface activity/biocidal activity of the different compounds were discussed. 相似文献
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Synthesis,Surface-Active Properties,and Antimicrobial Activities of New Neutral and Cationic Trimeric Surfactants 总被引:3,自引:1,他引:2
Marcelo C. Murguía Mariano D. Cristaldi Ayelén Porto José Di Conza Ricardo J. Grau 《Journal of surfactants and detergents》2008,11(1):41-48
Neutral and cationic series of new trimeric β-hydroxy amino or ammonium surfactants were synthesized via a two-step process
involving the Williamson etherification and regioselective oxirane ring opening with primary and tertiary amines, which afforded
good to excellent yields. The synthesized compounds were obtained in high purity by a simple purification procedure on column
chromatography. The critical micelle concentration (CMC), effectiveness of surface tension reduction (γ
CMC), surface excess concentration (Γ), and area per molecule at the interface (A) were determined and values indicate that the cationic series is characterized by good surface-active and self-aggregation
properties. The antimicrobial activities are reported for the first time against representative bacteria and fungi for trimeric
compounds. The antimicrobial potency was found to be dependent on the target microorganism (Gram-positive bacteria > fungi > Gram-negative
bacteria), as well as both the neutral or ionic nature (cationic > neutral) and alkyl chain length (tri-C12 > tri-C18 > tri-C8) of the compounds. The tri-C8 and tri-C18 compounds were found to be almost inactive and the tri-C12 compounds, the most potent antimicrobial surface-active agents from the synthesized series. The trimeric C12 cationic compound was found to be comparable to benzalkonium chloride against Gram-positive bacteria and fungi, in vitro.
The antimicrobial effectiveness of this new compound and the facile two-step procedure for synthesizing it with an excellent
overall yield (92%) provide a cost effective trimeric gemini surfactant.
相似文献
Ricardo J. GrauEmail: |
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Antimicrobial peptides (AMPs) are regarded as a new generation of antibiotics. Besides antimicrobial activity, AMPs also have antibiofilm, immune-regulatory, and other activities. Exploring the mechanism of action of AMPs may help in the modification and development of AMPs. Many studies were conducted on the mechanism of AMPs. The present review mainly summarizes the research status on the antimicrobial, anti-inflammatory, and antibiofilm properties of AMPs. This study not only describes the mechanism of cell wall action and membrane-targeting action but also includes the transmembrane mechanism of intracellular action and intracellular action targets. It also discusses the dual mechanism of action reported by a large number of investigations. Antibiofilm and anti-inflammatory mechanisms were described based on the formation of biofilms and inflammation. This study aims to provide a comprehensive review of the multiple activities and coordination of AMPs in vivo, and to fully understand AMPs to realize their therapeutic prospect. 相似文献
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利用微量肉汤稀释法测定3-对烯-1-胺(1)及其席夫碱衍生物(2a~2l)对革兰氏阳性菌金黄色葡萄球菌、革兰氏阴性菌肺炎克雷伯氏菌及真菌白色念珠菌的抑菌活性,并讨论了构效关系。结果表明:3-对烯-1-胺及其部分席夫碱衍生物对这3种菌具有一定的抑菌活性,其中化合物1对金黄色葡萄球菌的抑菌活性最强,最小抑菌浓度(MIC)值为56.25 mg/L;化合物2h和2i对肺炎克雷伯氏菌的抑菌活性最强,MIC值均为112.5 mg/L;化合物2l对白色念珠菌的抑菌活性最强,MIC值为28.125 mg/L。构效关系分析结果表明:向3-对烯-1-胺席夫碱衍生物中引入Br、Cl等卤素后,能显著增强抑菌活性;含有吡啶环的3-对烯-1-胺席夫碱衍生物对真菌白色念珠菌的抑菌活性明显要高于含呋喃环、吡咯环或噻吩环的3-对烯-1-胺席夫碱衍生物。 相似文献
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以胺和氨基酸乙酯与氯代乙酰氯反应,合成了N-烷基(芳基)或N,N-二烷基-2-氯乙酰胺和α-氯乙酰氨基酸乙酯二类植物生长调节剂。 相似文献
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以孕烯醇酮为原料,通过对孕烯醇酮的C-17 ''支链进行化学修饰,设计合成了18个甾核的C-17 ''-支链为苯并咪唑基取代的甾体化合物,通过IR、1H NMR、13C NMR和HRMS 对化合物进行了结构表征,采用溴化噻唑蓝四氮唑(MTT)法测试了这些化合物对人口腔上皮癌细胞(KB)、宫颈癌细胞(HeLa)、人肝癌细胞(HepG)、人鼻咽癌细胞(CNE-2)、乳腺癌细胞(BT474)、卵巢癌细胞(SKOV3)的体外抑制活性。结果表明,部分化合物具有中等程度的活性,其中氟基取代的苯并咪唑甾体化合物5c和6c对人体卵巢癌细胞(SKOV3)具有良好的选择性抑制作用,IC50 (半抑制浓度)值分别为(15.4±3.8)和(9.2±0.5)μmol/L。该类化合物可为设计开发新型抗肿瘤药物提供参考。 相似文献
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In the context of the new life-threatening COVID-19 pandemic caused by the SARS-CoV-2 virus, finding new antiviral and antimicrobial compounds is a priority in current research. Pyridine is a privileged nucleus among heterocycles; its compounds have been noted for their therapeutic properties, such as antimicrobial, antiviral, antitumor, analgesic, anticonvulsant, anti-inflammatory, antioxidant, anti-Alzheimer’s, anti-ulcer or antidiabetic. It is known that a pyridine compound, which also contains a heterocycle, has improved therapeutic properties. The singular presence of the pyridine nucleus, or its one together with one or more heterocycles, as well as a simple hydrocarbon linker, or grafted with organic groups, gives the key molecule a certain geometry, which determines an interaction with a specific protein, and defines the antimicrobial and antiviral selectivity for the target molecule. Moreover, an important role of pyridine in medicinal chemistry is to improve water solubility due to its poor basicity. In this article, we aim to review the methods of synthesis of pyridine compounds, their antimicrobial and antiviral activities, the correlation of pharmaceutical properties with various groups present in molecules as well as the binding mode from Molecular Docking Studies. 相似文献
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The most challenge task in the building up of surface-active molecules is maximizing their surface activity with good biological activity. A nonionic surfactant (N-isatin-EO m-C n where m is 5, 7 and 9 ethylene glycol units and n is 8, 10 and 12) is achieved by first reacting isatin with chloroacetic acid and then with different types of ethoxylated (C8–C12) fatty alcohols that possess 5, 7 and 9 ethylene oxide units. The prepared surfactants were characterized by FTIR and 1H NMR to confirm the structure. The surface activity, biodegradability, antimicrobial, and antifungal activity of the surfactants were evaluated. In addition, quantum chemical calculations and computations of oral bioavailability were performed. The obtained data show that all the synthesized compounds had good surface activity, biodegradability and biological activity. 相似文献
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以4-苯甲氧基苯肼盐酸盐为原料,经过3步反应,以较高产率合成了9个新型吲哚-3-羧酸类化合物,其结构均经IR、1HNMR、13CNMR和ESI-MS表征确认。初步葡萄糖消耗活性试验表明,所合成化合物均对Hep G2细胞有一定的促葡萄糖消耗活性,其中化合物2-甲基-1-(4-甲氧基苯磺酰基)-5-苄氧基-吲哚-3-丙酸、2-甲基-1-(4-甲基苯磺酰基)-5-苄氧基-吲哚-3-丙酸及2-甲基-1-(4-硝基苯磺酰基)-5-苄氧基-吲哚-3-丁酸的促葡萄糖消耗活性强于先导化合物GY3与阳性对照二甲双胍,值得进一步深入研究。 相似文献
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仙人掌提取物的抑菌作用 总被引:12,自引:1,他引:12
分别对食用仙人掌(OpuntiaMiloaAlta)和野生仙人掌 (OpuntiadilleniiHaw)提取物进行了抑菌作用、最低抑菌和杀菌条件的研究。实验结果表明:野生仙人掌提取物对大肠杆菌和枯草芽孢杆菌有明显的抑制作用,食用仙人掌提取物的抑菌作用效果不明显。野生仙人掌乙醇提取物 (odh)最小抑菌质量分数分别为:大肠杆菌w(odh) =2. 5%,枯草芽孢杆菌w(odh) =5%;最低杀菌质量分数分别为:大肠杆菌w(odh) =5%,枯草芽孢杆菌w(odh) =10%。此外,正交实验的最佳抑菌条件为:提取物w(odh) =10%,提取剂φ(乙醇) =85%,pH=4 5。 相似文献
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Murat Arslan A. Yasemin Öztop Nurettin Şahiner 《Polymer-Plastics Technology and Engineering》2017,56(12):1295-1306
Acrylamide/4-vinyl pyridine hydrogels were synthesized by radiation polymerization technique using a γ-irradiator. The prepared radiation-synthesized acrylamide/4-vinyl pyridine hydrogels were then treated using a modifying agent with aromatic functional group. The modifying agent used in the modification of acrylamide/4-vinyl pyridine hydrogels was the N-aromatic alkyl quaternizing agent of chloromethyl benzene. The functional group on the modified acrylamide/4-vinyl pyridine hydrogels was confirmed with Fourier transform infrared (FTIR) spectrometry. Thermal analysis, surface morphology investigation, and swelling of the modified and unmodified hydrogels were completed. The antibacterial and antifungal activities of the modified and unmodified hydrogels were also tested against gram-positive Staphylococcus aureus (ATCC 25923); two gram-negative Escherichia coli (ATCC 25922), and Pseudomonas aeruginosa (ATCC 27853) human pathogenic bacteria and a fungal strain—Candida albicans (ATCC 10231) for their MBC values. It was found that acrylamide/4-vinyl pyridine hydrogels do not possess biocidal properties, whereas the modified form of acrylamide/4-vinyl pyridine?chloromethyl benzene showed highly bactericidal characteristics. 相似文献
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