A new dihydrobenzofuran derivative from the endophytic fungus Botryosphaeria mamane PSU-M76

One new dihydrobenzofuran derivative, botryomaman (1), was isolated from the broth extract of the endophytic fungus Botryosphaeria mamane PSU-M76 along with six known compounds, 2,4-dimethoxy-6-pentylphenol, (R)-(-)-mellein, primin, cis-4-hydroxymellein, trans-4-hydroxymellein and 4,5-dihydroxy-2-hexenoic acid. The structures were assigned by spectroscopic methods. All compounds were tested for antibacterial activity against Staphylococcus aureus ATCC 25923 and methicillin-resistant S. aureus SK1. Primin showed the best activity against both strains with equal MIC values of 8 microg/ml.     

Synthesis of Novel Flavanone Derivatives and Their Anti Staphylococcus aureus Evaluation

The authors synthesized two novel flavanones bearing iso-pentenyl side chain and evaluated their anti Staphylococcus aureus(S. aureus) activity. The target compounds 7a[2-5'-(1",2"-dimethylallyl)-2'-methoxy-4',5,7-tetrahydroxyflavanone] and 7b[2-5'-(1",2"-dimethylallyl)-3'-methoxy-4',5,7-tetrahydroxyflavanone] were synthesized respectively through total four steps starting from 2,4,6-trihydroxy acetophenone(3) and the corresponding iso-pentenyl substituted benzaldehyde(1), in which the 1,2-dimethyl-2-propenyl group had been introduced previously via abnormal Claisen rearrangement. The bioactivities of the two flavanones against S. aureus strains ATCC 25923, 29213, and MRSA 252 were evaluated, showing the same minimum inhibitory concentration(MIC) value of 16 μg/mL.     

Synthesis, antibacterial and antifungal activities of 3-aryl-5-(pyridin-3-yl)-4,5-dihydropyrazole-1-carbothioamide derivatives

A new series of 3-aryl-5-(pyridin-3-yl)-1-thiocarbamoyl-2-pyrazoline derivatives (4a-j) were prepared by the reaction of azachalcons 3a-j with thiosemicarbazide in ethanolic sodium hydroxide. The structure of synthesized compounds were confirmed by ¹H NMR and Mass spectral data. Their antibacterial activities against Escherichia coli (CTP 7624), Staphylococcus aureus (ATCC 6538), Staphylococcus epidermidis (ATCC 12229), Pseudomonas aeruginosa (ATCC 9027), Bacillus subtilis (ATCC 1156) and Micrococcus luteus (ATCC 9341) were investigated. Antifungal activity of compounds against Candida albicans and Candida globrata were found to be inactive. Compounds 4a-j were also evaluated for antituberculosis activity against Mycobacterium tuberculosis H ₃₇ Rv (ATCC 27294) in BACTEC 12B using a broth microdilution assay and Microplate Alamar Blue Assay (MABA). The preliminary results showed that compounds 4e, 4d and 4g had 87%, 93% and 92% inhibitory effect respectively.     

In vitro inhibitory properties of ferrocene-substituted chalcones and aurones on bacterial and human cell cultures

Two series of ten chalcones and ten aurones, where ferrocene replaces the C ring and with diverse substituents on the A ring were synthesized. The compounds were tested against two antibiotic-sensitive bacterial strains, E. coli ATCC 25922 and S. aureus ATCC 25923, and two antibiotic-resistant strains, S. aureus SA-1199B and S. epidermidis IPF896. The unsubstituted compound and those with methoxy substitution showed an inhibitory effect on all bacterial strains at minimum inhibitory concentrations ranging between 2 and 32 mg L(-1). For four of these compounds, the effect was bactericidal, as opposed to bacteriostatic. The corresponding organic aurones did not show growth inhibition, underscoring the role of the ferrocene group. The methoxy-substituted aurones and the unsubstituted aurone also showed low micromolar (IC(50)) activity against MRC-5 non-tumoral lung cells and MDA-MB-231 breast cancer cells, suggesting non-specific toxicity.     

Facile preparation of antibacterial polymer coatings via thiol-yne click photopolymerization

Novel antibacterial polymer coatings were prepared by a facile thiol-yne click photopolymerization of 1-propargyl-3-alkyl-1,3-diazanyl-2,4-cyclopentadiene bromide ([PAIM]Br) and tetra(3-mercapto-propionate) pentaerythritol (PETMP) (2:1 molar ratio) using 2,2-dimethoxy-2-phenylacetophenone (DMPA) as initiator. The antibacterial activity of the coatings was tested against Staphylococcus aureus (ATCC 292130) and Escherichia coli (ATCC 25922) by the dynamic shake method. The evaluation results revealed the antibacterial polymer coatings exhibited excellent inhibitory activity against S. aureus and E. coli, especially for S. aureus.     

Antimicrobial activity and pollen composition of honey samples collected from different provinces in Turkey

The antibacterial activity of honey samples from different sources were collected and investigated against Bacillus cereus, Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 27736, Morganella morganii, Micrococcus luteus NRRL B-4375, Escherichia coli ATCC 35218, and Candida albicans. Pathogens exhibited different sensitivities towards the honey samples. The results showed that majority of the honey samples (75%) generally inhibitied the bacteria tested. The honey samples which were obtained from Izmir (samples 1 and 2) proved more effective as inhibitors against P. aeruginosa, E. coli, and S. aureus. The honey which was obtained from Mu?la (sample 5) exhibited high anticandidal activity on C. albicans. A comparison of the honey samples on the basis of pollen content revealed that they were heterofloral, and samples which had highest antibacterial activity against P. aeruginosa, E. coli, and S. aureus were dominated by pollen from Chenopodiaceae/Amaranthaceae (sample 1), and Trifolium, Trigonella, Cyperaceae, Zea mays and Anthemis taxa (sample 2). The honey proved more effective on bacteria than antibiotics.     

Bioassay-guided purification and identification of antimicrobial components in Chinese green tea extract

The Chinese green tea extract was found to strongly inhibit the growth of major food-borne pathogens, Escherichia coli O157:H7, Salmonella Typhimurium DT104, Listeria monocytogenes, Staphylococcus aureus, and a diarrhoea food-poisoning pathogen Bacillus cereus, by 44-100% with the highest activity found against S. aureus and lowest against E. coli O157:H7. A bioassay-guided fractionation technique was used for identifying the principal active component. A simple and efficient reversed-phase high-speed counter-current chromatography (HSCCC) method was developed for the separation and purification of four bioactive polyphenol compounds, epicatechin gallate (ECG), epigallocatechin gallate (EGCG), epicatechin (EC), and caffeine (CN). The structures of these polyphenols were confirmed with mass spectrometry. Among the four compounds, ECG and EGCG were the most active, particularly EGCG against S. aureus. EGCG had the lowest MIC90 values against S. aureus (MSSA) (58 mg/L) and its methicilin-resistant S. aureus (MRSA) (37 mg/L). Scanning electron microscopy (SEM) studies showed that these two compounds altered bacterial cell morphology, which might have resulted from disturbed cell division. This study demonstrated a direct link between the antimicrobial activity of tea and its specific polyphenolic compositions. The activity of tea polyphenols, particularly EGCG on antibiotics-resistant strains of S. aureus, suggests that these compounds are potential natural alternatives for the control of bovine mastitis and food poisoning caused by S. aureus.     

Facile green one‐pot synthesis of novel thiazolo[3,2‐a]pyrimidine derivatives using Fe3O4@l‐arginine and their biological investigation as potent antimicrobial agents

Thiazolopyrimidine derivatives are well known because of their excellent therapeutic properties. In this investigation, an effective one‐pot three‐component method is described for the synthesis of novel 2‐[(Z )‐1‐(substituted phenyl)methylidine]‐7‐methyl‐3‐oxo‐5‐(substituted phenyl)‐2,3‐dihydro‐5H ‐thiazolo[3,2‐a]pyrimidine‐6‐carboxilic acid tert ‐butyl ester derivatives by condensation reaction of 3,4‐dihydropyrimidine‐2(1H )‐thiones, various aromatic aldehydes and chloroacetyl chloride under reflux conditions in the presence of Fe₃O₄@l ‐arginine nanoparticles as a magnetically reusable and eco‐friendly catalyst with short reaction times and moderate yields. The chemical structures of all synthesized compounds were determined using infrared, ¹H NMR and ¹³C NMR spectroscopies. In vitro antimicrobial activities of 3,4‐dihydropyrimidine‐2(1H )‐thiones and newly fused thiazolo[3,2‐a]pyrimidine derivatives were examined using the well diffusion method against diverse pathogenic strains, namely Staphylococcus aureus ATCC 6538, S. epidermidis ATCC 12228, Escherichia coli ATCC 8739 and Pseudomonas aeruginosa ATCC 9027 (bacteria), Candida albicans ATCC 10231 (yeast) and Aspergillus niger ATCC 16404 (fungus). The compounds having 2‐hydroxy, 4‐hydroxy, 2‐chloro and 4‐chloro groups attached to the phenyl ring on the pyrimidine and 4‐CH₃, 4‐OCH₃ and 3‐NO₂ groups attached to benzylidine on the thiazolo moiety showed significant antibacterial activity.     

Synthesis and Evaluation of Novel [1,2,4]Triazolo[1,5‐c]quinazoline Derivatives as Antibacterial Agents

A series of new 2‐aryl‐5‐methyl‐[1,2,4]triazolo[1,5‐c ]quinazoline derivatives ( 5a – 5g ) have been synthesized by the reaction of 3‐amino‐2‐methylquinazolin‐4‐(3H )‐one ( 3 ) with aromatic nitriles in potassium tert ‐butoxide under reflux conditions. 3‐Amino‐2‐methylquinazolin‐4‐(3H )‐one ( 3 ) was synthesized by the reaction 2‐methyl‐4H ‐benzo[d ][1,3]oxazin‐4‐one ( 2 ) with hydrazine hydrate. The chemical structure of products was confirmed by IR, ¹H, ¹³C NMR and elemental analysis. These compounds were screened for antibacterial [Staphylococcus aureus (ATCC 25923), Bacillus cereus (ATCC 11778), Micrococcus luteus (ATCC 9341), Escherichia coli (ATCC 25922), and Pseudomonas aeruginosa (ATCC 27853)] activities, using the zone inhibition method.     

新型1,2,4-三唑糖苷衍生物的合成及体外抗菌活性测试

以取代1,2,3-噻二唑为原料,合成了一系列未见文献报道的含有1,2,3-噻二唑、1,2,4-三唑的双杂环类硫苷化合物(6a~6d)。 目标化合物的结构经过1H NMR、13C NMR和IR等技术手段表征确认,重点对比了含西弗碱化合物5与还原后化合物6的抗菌活性变化。 体外抑菌测试结果显示,所有化合物对大肠杆菌、金黄色葡萄球菌和白色念珠菌均表现出较好的抑制活性,含有西弗碱化合物5的抗菌活性普遍优于还原后化合物6,其中化合物5d表现出很强的抗菌活性,其最小抑菌浓度优于市售抗菌药氟康唑;所有目标化合物对白色念珠菌的最小抑菌浓度均小于或等于32 mg/L。     

Three antibacterial naphthoquinone analogues from cultured mycobiont of lichen Astrothelium sp.

<正>A new naphthoquinone compound named 7-hydroxyl-8-methoxyltrypethelone 3 together with two known compounds trypethelone 1 and trypethelone methyl ether 2 was isolated from cultured mycobiont of Astrothelium sp.The structures were elucidated by 1D and 2D NMR spectroscopic analysis as well as comparison with those reported in literatures.Compound 1 displayed significant antibacterial activity against Bacillus subtilis(ATCC 6633),and showed modest antibacterial activity against Staphylococcus aureus col(MRSA)(CGMCC 1.2465),while compounds 2 and 3 showed modest antibacterial activity against Enterococcus faecalis 850E(CGMCC 1.2135) and S.aureus col(MRSA)(CGMCC 1.2465).     

Gallomyrtucommulones G and H,New Phloroglucinol Glycosides,from Bioactive Fractions of Myrtus communis against Staphylococcus Species

Myrtaceae family is a continuous source of antimicrobial agents. In the search for novel antimicrobial agents against Staphylococcus species, bioactive fractions of Myrtus communis L., growing in the Sardinia island (Italy) have been investigated. Their phytochemical analysis led us to isolate and characterize four alkylphloroglucinol glycosides (1–4), three of them gallomyrtucommulones G–H (1,2), and myrtucommulonoside (4) isolated and characterized for the first time. The structures of the new and known compounds, endopreroxide G3 (5), myricetin-3-O-glycosides (6,7) were determined based on the spectroscopic evidence including 1D-/2D-NMR and HR-MS spectrometry. Enriched fractions as well as pure compounds were tested for their antimicrobial activity by broth micro-dilution assay against Staphylococcus epidermidis and S. aureus. Results reported herein demonstrated that gallomyrtucommulone G (1) showed a selective antimicrobial activity against both S. aureus strains (ATCC 29213 and 43300) until 16 μg/mL while gallomyrtucommulone D (3) showed the best growth inhibition value at 64 μg/mL.     

Solvent-free microwave extraction and hydrodistillation of essential oils from endemic Origanum husnucanbaseri H. Duman, Aytac & A. Duran: comparison of antibacterial activity and contents

The essential oils (EOs) obtained by solvent-free microwave extraction (SFME) and hydrodistillation (HD) from endemic Origanum husnucanbaseri H. Duman, Aytac & A. Duran were investigated using the gas chromatography-mass spectrometry system. The main constituents of both oils obtained from SFME and HD from O. husnucanbaseri are borneol (15.2-12.8%), α-terpineol (12.3-10.8%) and trans-sabinene hydrate (11.8-9.92%). The EO obtained from SFME contained substantially higher amounts of oxygenated compounds and lower amounts of monoterpenes than that from HD. The antibacterial activities of the EOs from SFME and HD were evaluated by the disc diffusion method against six bacterial strains. The EO extracted by SFME was more effective than the EO extracted by HD against the tested bacteria, except for Klebsiella pneumoniae American type culture collection (ATCC) 13883. Streptococcus pyogenes ATCC 19615 and Staphylococcus aureus ATCC 25923 in particular were more sensitive against the EO extracted by SFME.     

Composition and antimicrobial activity of Seseli globiferum essential oil

The essential oil from aerial parts of Seseli globiferum Vis. obtained by hydrodistillation with Clevenger-type apparatus was analyzed by GC-MS. Twenty-eight compounds were identified, representing 99.4% of the total oil. The main components of the oil were sabinene (38.0%), alpha-pinene (21.2%) and beta-phellandrene (13.5%). The microbial growth inhibitory properties of the isolated essential oil were determined using the broth microdilution method against seven bacterial species: Salmonella typhimurium (ATCC 13311), Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), Enterobacter cloacae (clinical isolates), Bacillus cereus (clinical isolates), Staphylococcus aureus (ATCC 25923), Staphylococcus epidermidis (ATCC 12228), Micrococcus flavus (ATCC 10240) and three fungal species: Aspergillus niger (ATCC 6275), Aspergillus versicolor (ATCC 11730), Trichoderma viride (IAM 5061) and Penicillium funiculosum (ATCC 36839). The essential oil showed activity against bacteria P. aeruginosa, followed by M flavus, L. monocytigenes and E. coli, and all investigated fungal species.     

苯并异噻唑啉酮类化合物的合成与活性研究

通过烷基醇与固体三光气(BTC)反应后加入1,2-苯并异噻唑啉-2(3H)-酮(BIT)继续反应的“一锅法”制备了8种未见文献报道的2-(苯并异噻唑啉-3-酮-2-基)甲酸酯类化合物.化合物结构经IR、1HNMR和元素分析确认,并且对枯草芽孢杆菌、金黄色葡萄球菌、嗜水单细胞菌和大肠杆菌进行了初步抑菌活性实验,实验结果表...     

Preparation and Spectral and Biological Investigation of vic-Dioxime Ligands Containing Piperazine Moiety and Their Mononuclear Transition-Metal Complexes

Two vic-dioxime ligands, N-(4-benzylpiperazine-1-yl) p-tolylglyoxime (L¹H₂) and N,N′-bis(4-benzylpiperazine-1-yl) glyoxime (L²H₂), containing piperazine moieties were synthesized, and their Ni(II), Cu(II), Co(II) and Zn(II) complexes were obtained. The ligands were characterized by elemental analysis, Fourier transform–infrared (FT-IR), ultraviolet–visible NMR (¹H, ¹³C, and heteronuclear multiple-bond correlation), and electrospray ionization (ESI) mass spectrometry. The isolated complexes were characterized by a combination of elemental analysis, IR, UV-vis, and ESI mass spectrometry and in the case of Ni(II) and Zn(II) complexes by ¹H and ¹³C NMR spectroscopy. The electrochemical behaviors of the ligands and their complexes were studied by cyclic voltammetry (CV) in dimethylsulfoxide solution containing tetrabutylammoniumtetrafluoroborate (TBATFB). The antibacterial activity was also studied against S. aureus ATCC 25923, S. aureus ATCC 29213, S. mutans RSHM 676, E. faecalis ATCC 29212, E. coli ATCC 25922, and P. aeruginosa ATCC 27853. The antimicrobial test results indicated that all the compounds have good antibacterial activity against P. auriginosa ATCC 27853 bacteria and were as effective as ampicilin.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resources: Full experimental and spectral details.]     

Synthesis,Characterization, and Antibacterial Activity of Novel (1H‐Benzo[d]imidazole‐2‐yl)‐6‐(diethylamino)‐3H‐one‐xanthene,Phenoxazine, and Oxazine

A series of novel (1H‐benzo[d]imidazole‐2‐yl)‐6‐(diethylamino)‐3H‐one‐xanthene, phenoxazine, and oxazine derivatives have been synthesized from 2‐(2′,4′‐dihydroxyphenyl) benzimidazole intermediate. Synthesized compounds 8a , 8b , 8c , 8d are fluorescent in solution, photophysical properties of compounds were studied and results revealed that compounds absorb and emit in UV–visible region with good fluorescence quantum yield. Synthesized compounds are thermally stable up to 300°C. The antibacterial activities of the synthesized compounds were studied by the well‐diffusion method. Escherichia coli (ATTC‐25922), Staphylococcus aureus (ATCC‐25923), Micrococcus (ATCC‐4698), and Bacillus subtilis (ATCC‐55422) were used to investigate the antibacterial activities.     

Chemical composition and in vitro antibacterial activity of the essential oil of Phthirusa adunca from Venezuelan Andes

In this paper, preliminary studies on the chemical characterization of Phthirusa adunca Meyer essential oil, obtained by hydrodistillation, is presented. The separation of the components was performed by GC-MS. Twenty-three compounds (94.5% of the sample) were identified of which the three major ones (76% of the sample) were beta-phellandrene (38.1%), germacrene D (26.8%) and beta-pinene (11.5%). The essential oil showed a broad spectrum of activity against Salmonella Typhi CDC 57 (100 microg/mL), Staphylococcus aureus ATCC 25923 (200 microg/mL), Enterococcus faecalis ATCC 29212 (250 microg/mL), Escherichia coli ATCC 25922 y Klebsiella pneumoniae ATCC 23357 (500 microg/mL). This is the first report on the composition and activity of the essential oil of this species.     

Microbial screening of novel synthesized formazans having amide linkagesΦ

Formazans 5(a‐j) have been prepared by the condensation between schiff base 3 and diazonium salt of substituted 2‐amino benzothiazole 4(a‐j) . The intermediate schiff base 3 was synthesized by the condensation of p‐nitrobenzolyhydrazide 1 with thiophene‐2‐aldehyde 2 . All the compounds have been screened for their antifungal activity against Candida albicans (ATCC‐64550), Candida krusei (ATCC‐14243) and Candida parapsilosis (ATCC‐22019) and antibacterial activity against Escherchia coli (ATCC‐6538), Staphylococcus aureus (ATCC‐6538), Pseudomonas aeruginosa (ATCC‐1539) and Bacillus substilis (ATCC‐6633). The structures of the synthesised compounds 5(a‐j) have been characterized on the basis of their elemental analysis and spectral data (UV, IR, ¹H NMR, ¹³C NMR and Mass).