scholarly journals New Benzofuranoids and Phenylpropanoids from the Mangrove Endophytic Fungus, Aspergillus sp. ZJ-68

Marine Drugs ◽  
2019 ◽  
Vol 17 (8) ◽  
pp. 478 ◽  
Author(s):  
Runlin Cai ◽  
Hongming Jiang ◽  
Zhenming Zang ◽  
Chunyuan Li ◽  
Zhigang She
Keyword(s):  
Inhibitory Activity ◽  
Pathogenic Bacteria ◽  
Data Interpretation ◽  
Antibacterial Activities ◽  
Vitro Assay ◽  
E Coli ◽  
Ic50 Value ◽  
Aspergillus Sp ◽  
New Compounds

Three new benzofuranoids, asperfuranoids A–C (1–3), two new phenylpropanoid derivatives (6 and 7), and nine known analogues (4, 5, and 8–14) were isolated from the liquid substrate fermentation cultures of the mangrove endopytic fungus Aspergillus sp. ZJ-68. The structures of the new compounds were determined by extensive spectroscopic data interpretation. The absolute configurations of 1–3 were assigned via the combination of Mosher’s method, and experimental and calculated electronic circular dichroism (ECD) data. Compounds 4 and 5 were a pair of enantiomers and their absolute configurations were established for the first time on the basis of their ECD spectra aided with ECD calculations. All isolated compounds (1–14) were evaluated for their enzyme inhibitory activity against α-glucosidase and antibacterial activities against four pathogenic bacteria (Staphylococcus aureus, Escherichia coli, Bacillus subtilis, and Pseudomonas aeruginosa). Among them, compound 6 exhibited potent inhibitory activity against α-glucosidase in a standard in vitro assay, with an IC50 value of 12.4 μM, while compounds 8 and 11 showed activities against S. aureus, E. coli, and B. subtilis, with MIC values in the range of 4.15 to 12.5 μg/mL.

scholarly journals Novel Thiosemicarbazone Derivatives: In Vitro and In Silico Evaluation as Potential MAO-B Inhibitors

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6640
Author(s):  
Derya Osmaniye ◽  
Berkant Kurban ◽  
Begüm Nurpelin Sağlık ◽  
Serkan Levent ◽  
Yusuf Özkay ◽  
...  
Keyword(s):  
Inhibitory Activity ◽  
Active Sites ◽  
Docking Study ◽  
Fluorometric Method ◽  
Mao B ◽  
Micromolar Concentration ◽  
Ic50 Value ◽  
Competitive Inhibitors ◽  
New Compounds

MAO-B inhibitors are frequently used in the treatment of neurodegenerative diseases such as Parkinson’s and Alzheimer’s. Due to the limited number of compounds available in this field, there is a need to develop new compounds. In the recent works, it was shown that various thiosemicarbazone derivatives show hMAO inhibitory activity in the range of micromolar concentration. It is thought that benzofuran and benzothiophene structures may mimic structures such as indane and indanone, which are frequently found in the structures of such inhibitors. Based on this view, new benzofuran/benzothiophene and thiosemicarbazone hybrid compounds were synthesized, characterized and screened for their hMAO-A and hMAO-B inhibitory activity by an in vitro fluorometric method. The compounds including methoxyethyl substituent (2b and 2h) were found to be the most effective agents in the series against MAO-B enzyme with the IC50 value of 0.042 ± 0.002 µM and 0.056 ± 0.002 µM, respectively. The mechanism of hMAO-B inhibition of compounds 2b and 2h was investigated by Lineweaver–Burk graphics. Compounds 2b and 2h were reversible and non-competitive inhibitors with similar inhibition features as the substrates. The Ki values of compounds 2b and 2h were calculated as 0.035 µM and 0.046 µM, respectively, with the help of secondary plots. The docking study of compound 2b and 2h revealed that there is a strong interaction between the active sites of hMAO-B and analyzed compound.

scholarly journals Antibacterial Activities and Characterization of Novel Inhibitors of LpxC

2002 ◽  
Vol 46 (6) ◽  
pp. 1793-1799 ◽  
Author(s):  
John M. Clements ◽  
Fanny Coignard ◽  
Ian Johnson ◽  
Stephen Chandler ◽  
Shilpa Palan ◽  
...  
Keyword(s):  
Burkholderia Cepacia ◽  
Lipid A ◽  
Antibacterial Activities ◽  
Vitro Assay ◽  
Gram Negative ◽  
E Coli ◽  
Antibacterial Target ◽  
Derivatives Of

ABSTRACT Lipid A is the hydrophobic anchor of lipopolysaccharide (LPS) and forms the major lipid component of the outer monolayer of the outer membrane of gram-negative bacteria. Lipid A is required for bacterial growth and virulence, and inhibition of its biosynthesis is lethal to bacteria. UDP-3-O-(R-3-hydroxymyristoyl)-N-acetylglucosamine deacetylase (LpxC) is a metalloenzyme that catalyzes the second step in the biosynthesis of lipid A. Inhibitors of LpxC have previously been shown to have antibiotic activities. We have screened a metalloenzyme inhibitor library for antibacterial activities against an Escherichia coli strain with reduced LpxC activity. From this screen, a series of sulfonamide derivatives of the α-(R)-amino hydroxamic acids, exemplified by BB-78484 and BB-78485, have been identified as having potent inhibitory activities against LpxC in an in vitro assay. Leads from this series showed gram-negative selective activities against members of the Enterobacteriaceae, Serratia marcescens, Morganella morganii, Haemophilus influenzae, Moraxella catarrhalis, and Burkholderia cepacia. BB-78484 was bactericidal against E. coli, achieving 3-log killing in 4 h at a concentration 4 times above the MIC, as would be predicted for an inhibitor of lipid A biosynthesis. E. coli mutants with decreased susceptibility to BB-78484 were selected. Analysis of these mutants revealed that resistance arose as a consequence of mutations in the fabZ or lpxC genes. These data confirm the antibacterial target of BB-78484 and BB-78485 and validate LpxC as a target for gram-negative selective antibacterials.

Synthesis and Antibacterial Evaluation of Thiouracil Derivatives Contain-ing 1,2,4-Triazolo[1,5-a]Pyrimidine

2020 ◽  
Vol 17 ◽  
Author(s):  
Penglei Cui ◽  
Di Zhang ◽  
Xiumin Guo ◽  
Shujing Ji ◽  
Qingmei Jiang
Keyword(s):  
Staphylococcus Aureus ◽  
Bacillus Subtilis ◽  
Inhibitory Activity ◽  
Bacillus Amyloliquefaciens ◽  
Antibacterial Activities ◽  
Inhibitory Activities ◽  
New Compounds ◽  
Thiouracil Derivatives ◽  
Antibacterial Evaluation

: A series of new thiouracil compounds containing 1,2,4-triazolo[1,5-a]pyrimidine were designed and synthesized. The in vitro antibacterial activities of the new compounds against Bacillus amyloliquefaciens, Staphylococcus aureus and Bacillus subtilis were tested. The results showed that some of the new compounds had strong inhibitory activities against the tested bacteria. At the concentration of 50 μg/mL, the compound 12d had broad and the highest inhibitory activity with the 100% inhibition against the three tested strains, the same as norfloxacin which was used as the control.

scholarly journals IN SILICO AND IN VITRO ASSAY OF HGV ANALOGUE AS ANTIBACTERIAL

2019 ◽  
pp. 78-85
Author(s):  
Bambang Wijianto ◽  
RITMALENI . ◽  
HARI PURNOMO ◽  
ARIEF NURROCHMAD
Keyword(s):  
In Silico ◽  
Aldol Condensation ◽  
Antibacterial Activities ◽  
In Vitro Assay ◽  
Dilution Method ◽  
Qsar Study ◽  
Vitro Assay ◽  
E Coli ◽  
Parameterized Model

Objective: The objective of this research was to design a new analogue compound, hexagamavunon (HGV). Methods: New design of analogue compound, HGV, was performed by QSAR study using BuildQSAR program. In this QSAR study, parameterized model (PM3) method using the Polak-Ribière algorithm was applied to calculate the optimal geometric structures of the used compounds. The new analogue compound, HGV had been synthesized using aldol condensation reaction. The assay of antibacterial activities was performed using the dilution method. Molecular operating environment (MOE) program was used for protocol docking. Results: The results of QSAR study reveal the good relationship of antibacterial activities. The in vitro antibacterial activities of 2,6-bis((E)-3,5-dibromo-4-hydroxybenzylidene) cyclohexan-1-one (A113) indicates the good potential to against S. aureus, B. subtilis and E. coli with IC50 27.3 μg/ml, 30.9 μg/ml, 32 μg/ml respectively. This is in accordance with the in silico evaluation showing that 2,6-bis((E)-3,5-dibromo-4-hydroxybenzylidene) cyclohexan-1-one has lower docking score than both amoxicillin and cefoxitin do as the native ligand of receptor 3MZE. Conclusion: Based on in silico and in vitro assay, 2,6-bis((E)-3,5-dibromo-4-hydroxybenzylidene) cyclohexan-1-one (A113) has good antibacterial activities against S. aureus, B. subtilis, and E. coli.

Resorcylic Acid Lactones Produced by an Endophytic Penicillium ochrochloron Strain from Kadsura angustifolia

Planta Medica ◽  
2020 ◽  
Author(s):  
Hong Chuan Song ◽  
Dan Qin ◽  
Hai Yang Liu ◽  
Jin Yan Dong ◽  
Chuan You ◽  
...  
Keyword(s):  
Spectroscopic Analysis ◽  
Tumor Cell Line ◽  
Antibacterial Activities ◽  
Preparative Hplc ◽  
Solid Culture ◽  
Ic50 Value ◽  
Resorcylic Acid Lactones ◽  
New Compounds ◽  
First Time

AbstractFour new β-resorcylic acid lactones, including penochrochlactone A (2), 4-O-desmethyl-aigialomycin B (4), and penochrochlactones C and D (5 and 6), two compounds isolated from a natural source for the first time, 5α, 6β-acetonide-aigialomycin B (1) and penochrochlactone B (3), together with six known compounds, aigialomycin F (7), aigialomycins A, B, and D (8–10), zeaenol (11), and oxozeaenol (12), were isolated from a mycelial solid culture of the endophytic fungus Penicillium ochrochloron SWUKD4.1850 from the medicinal plant Kadsura angustifolia by sequential purification over silica gel, Sephadex LH-20 column chromatography, and preparative HPLC. Their structures were elucidated by extensive spectroscopic analysis and chemical conversions. In addition, all the new compounds were evaluated for their cytotoxic and antibacterial activities in vitro. Penochrochlactone C (5) displayed moderate cytotoxicity against the HeLa tumor cell line with an IC50 value of 9.70 µM. In the antibacterial assays, compounds 4 – 6 exhibited moderate activities against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa with MIC values between 9.7 and 32.0 µg/mL.

Acetate Kinase (AcK) is Essential for Microbial Growth and Betel-derived Compounds Potentially Target AcK, PhoP and MDR Proteins in M. tuberculosis, V. cholerae and Pathogenic E. coli: An in silico and in vitro Study

2019 ◽  
Vol 18 (31) ◽  
pp. 2731-2740 ◽  
Author(s):  
Sandeep Tiwari ◽  
Debmalya Barh ◽  
M. Imchen ◽  
Eswar Rao ◽  
Ranjith K. Kumavath ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
In Silico ◽  
Pathogenic Bacteria ◽  
In Vitro Study ◽  
Docking Studies ◽  
Acetate Kinase ◽  
E Coli ◽  
Pathogenic Escherichia Coli ◽  
Novel Target

Background: Mycobacterium tuberculosis, Vibrio cholerae, and pathogenic Escherichia coli are global concerns for public health. The emergence of multi-drug resistant (MDR) strains of these pathogens is creating additional challenges in controlling infections caused by these deadly bacteria. Recently, we reported that Acetate kinase (AcK) could be a broad-spectrum novel target in several bacteria including these pathogens. Methods: Here, using in silico and in vitro approaches we show that (i) AcK is an essential protein in pathogenic bacteria; (ii) natural compounds Chlorogenic acid and Pinoresinol from Piper betel and Piperidine derivative compound 6-oxopiperidine-3-carboxylic acid inhibit the growth of pathogenic E. coli and M. tuberculosis by targeting AcK with equal or higher efficacy than the currently used antibiotics; (iii) molecular modeling and docking studies show interactions between inhibitors and AcK that correlate with the experimental results; (iv) these compounds are highly effective even on MDR strains of these pathogens; (v) further, the compounds may also target bacterial two-component system proteins that help bacteria in expressing the genes related to drug resistance and virulence; and (vi) finally, all the tested compounds are predicted to have drug-like properties. Results and Conclusion: Suggesting that, these Piper betel derived compounds may be further tested for developing a novel class of broad-spectrum drugs against various common and MDR pathogens.

scholarly journals Antimicrobial Efficacy and Spectrum of Phosphorous-Fluorine Co-Doped TiO2 Nanoparticles on the Foodborne Pathogenic Bacteria Campylobacter jejuni, Salmonella Typhimurium, Enterohaemorrhagic E. coli, Yersinia enterocolitica, Shewanella putrefaciens, Listeria monocytogenes and Staphylococcus aureus

Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1786
Author(s):  
György Schneider ◽  
Bettina Schweitzer ◽  
Anita Steinbach ◽  
Botond Zsombor Pertics ◽  
Alysia Cox ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Campylobacter Jejuni ◽  
Food Industry ◽  
Pathogenic Bacteria ◽  
Antibacterial Activities ◽  
Tio2 Nps ◽  
E Coli ◽  
Foodborne Pathogenic Bacteria ◽  
And Staphylococcus Aureus ◽  
Co Doped

Contamination of meats and meat products with foodborne pathogenic bacteria raises serious safety issues in the food industry. The antibacterial activities of phosphorous-fluorine co-doped TiO2 nanoparticles (PF-TiO2) were investigated against seven foodborne pathogenic bacteria: Campylobacter jejuni, Salmonella Typhimurium, Enterohaemorrhagic E. coli, Yersinia enterocolitica, Shewanella putrefaciens, Listeria monocytogenes and Staphylococcus aureus. PF-TiO2 NPs were synthesized hydrothermally at 250 °C for 1, 3, 6 or 12 h, and then tested at three different concentrations (500 μg/mL, 100 μg/mL, 20 μg/mL) for the inactivation of foodborne bacteria under UVA irradiation, daylight exposure or dark conditions. The antibacterial efficacies were compared after 30 min of exposure to light. Distinct differences in the antibacterial activities of the PF-TiO2 NPs, and the susceptibilities of tested foodborne pathogenic bacterium species were found. PF-TiO2/3 h and PF-TiO2/6 h showed the highest antibacterial activity by decreasing the living bacterial cell number from ~106 by ~5 log (L. monocytogenes), ~4 log (EHEC), ~3 log (Y. enterolcolitca, S. putrefaciens) and ~2.5 log (S. aureus), along with complete eradication of C. jejuni and S. Typhimurium. Efficacy of PF-TiO2/1 h and PF-TiO2/12 h NPs was lower, typically causing a ~2–4 log decrease in colony forming units depending on the tested bacterium while the effect of PF-TiO2/0 h was comparable to P25 TiO2, a commercial TiO2 with high photocatalytic activity. Our results show that PF-co-doping of TiO2 NPs enhanced the antibacterial action against foodborne pathogenic bacteria and are potential candidates for use in the food industry as active surface components, potentially contributing to the production of meats that are safe for consumption.

scholarly journals Flavone-Rich Fractions and Extracts from Oroxylum indicum and Their Antibacterial Activities against Clinically Isolated Zoonotic Bacteria and Free Radical Scavenging Effects

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1773
Author(s):  
Patchima Sithisarn ◽  
Piyanuch Rojsanga ◽  
Pongtip Sithisarn
Keyword(s):  
Antibacterial Activities ◽  
Inhibitory Effect ◽  
Total Flavonoid ◽  
Total Phenolic ◽  
Antibacterial Effects ◽  
E Coli ◽  
Young Fruit ◽  
Oroxylum Indicum ◽  
Zoonotic Bacteria

Oroxylum indicum extracts from the seeds collected from Lampang and Pattani provinces in Thailand, and young fruits and flowers exhibited in vitro display antioxidant and antibacterial activities against clinically isolated zoonotic bacteria including Staphylococcus intermedius, Streptococcus suis, Pseudomonas aeruginosa, β-hemolytic Escherichia coli and Staphylococcus aureus. The orange crystals and yellow precipitates were obtained from the preparation processes of the seed extracts. The orange-red crystals from the seeds collected from Lampang province exhibited strong in vitro 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging effects (EC50 value = 25.99 ± 3.30 μg/mL) and antibacterial effects on S. intermedius and β-hemolytic E. coli while the yellow precipitate from the same source exhibited only antioxidant activity. Quantitative analysis of phytochemicals in O. indicum samples by spectrophotometric and HPLC techniques showed that they contained different amounts of total phenolic, total flavonoid and three major flavones; baicalin, baicalein and chrysin contents. Young fruit extract, which contained low amounts of flavone contents, still promoted antibacterial effects against the tested bacteria with IC50 values lower than 1 mg/mL and MIC values between 4 to 10 mg/mL in S. intermedius, S. aureus and S suis while higher IC50 and MIC values against P. aeruginosa and β-hemolytic E. coli were found. From scanning electron microscopy, the extract of the young fruit of O. indicum promoted morphological changes in the bacterial cells by disrupting the bacterial cell walls, inducing leakage of the cellular content, and generating the abnormal accumulation of cells. The mechanism of action of the extract for this antibacterial effect may be the disruption of the cell membrane and abnormal cell aggregations. Regression analysis of the results suggests the correlation between total phenolic and total flavonoid contents and antioxidant and antibacterial effects. Baicalin was found to have a high correlation with an inhibitory effect against β-hemolytic E. coli while three unidentified peaks, which could be flavones, showed high correlations with an inhibitory effect against S. intermedius, S. suis, P. aeruginosa and S. aureus.

scholarly journals Tantalum doped SiO2-CaO-P2O5 based bioactive glasses: Investigation of in vitro bioactivity and antibacterial activities

2020 ◽  
Vol 6 (1) ◽  
pp. 10-22
Author(s):  
Zakaria Tabia ◽  
Sihame Akhtach ◽  
Khalil El Mabrouk ◽  
Meriame Bricha ◽  
Khalid Nouneh ◽  
...  
Keyword(s):  
Antibacterial Activities ◽  
Silica Matrix ◽  
Morphological Properties ◽  
Metallic Ions ◽  
X Ray Diffraction ◽  
Bioactive Glasses ◽  
E Coli ◽  
Fourier Transformed Infrared Spectroscopy ◽  
Electron Scanning Microscopy

AbstractMultifunctionality can be achieved for bioactive glasses by endowing them with multiple other properties along with bioactivity. One way to address this topic is by doping these glasses with therapeutic metallic ions. In this work, we put under investigation a series of bioactive glasses doped with tantalum. We aim to study the effect of tantalum, on the structure, bioactivity and antibacterial property of a ternary bioactive glass composition based on SiO2-CaO-P2O5. Fourier Transformed Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD) and Electron Scanning Microscopy (SEM) were used to assess the structural and morphological properties of these glasses and monitor their changes after in vitro acellular bioactivity test. Antibacterial activity was tested against gram positive and negative bacteria. Characterization results confirmed the presence of calcium carbonate crystallites along with the amorphous silica matrix. The assessment of bioactivity in SBF indicated that all compositions showed a fast bioactive response after only six hours of immersion period. However, analytical characterization revealed that tantalum introduced a slight latency in hydroxyapatite deposition at higher concentrations (0.8-1 %mol). Antibacterial test showed that tantalum ions had an inhibition effect on the growth of E. coli and S. aureus. This effect was more pronounced in compositions where mol% of tantalum is superior to 0.4%. These results proved that tantalum could be used, in intermediate proportions, as a promising multifunctional dopant element in bioactive glasses for bone regeneration applications.

scholarly journals Monoclonal antibodies specific to a Ca2+-bound form of lipocortin I distinguish its Ca2+-dependent phospholipid-binding ability from its ability to inhibit phospholipase A2

1990 ◽  
Vol 269 (3) ◽  
pp. 709-715 ◽  
Author(s):  
H Hayashi ◽  
M K Owada ◽  
S Sonobe ◽  
K Domae ◽  
T Yamanouchi ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Phospholipase A2 ◽  
Inhibitory Activity ◽  
Biological Effects ◽  
Free Form ◽  
E Coli ◽  
Phospholipid Binding ◽  
Ef Hand

Lipocortin I, a Ca2(+)-and phospholipid-binding protein without EF-hand structures, has many biological effects in vitro. Its actual role in vivo, however is unknown. We obtained and characterized five monoclonal antibodies to lipocortin I. Two of these monoclonal antibodies (L2 and L4-MAbs) reacted with the Ca(+)-bound form of lipocortin I, but not with the Ca2(+)-free form, both in vivo and in vitro. Lipocortin I required greater than or equal to 10 microM-Ca2+ to bind the two antibodies, and this Ca2+ requirement was not affected by phosphatidylserine. L2-MAb abolished the phospholipase A2 inhibitory activity of lipocortin I and inhibited its binding to Escherichia coli membranes and to phosphatidylserine in vitro. L4-MAb abolished the phospholipase A2 inhibitory activity of lipocortin I, but did not affect its binding to E. coli membranes or to phosphatidylserine. These findings indicated that the inhibition of phospholipase A2 by lipocortin I was not simply due to removal or capping of the substrates in E. coli membranes. Furthermore, an immunofluorescence study using L2-MAb showed the actual existence of Ca2(+)-bound form of lipocortin I in vivo.

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