Preparation, antibacterial effects and enzymatic degradation of 5-fluorouracil nucleosides

1980 ◽  
Vol 45 (11) ◽  
pp. 3217-3230 ◽  
Author(s):  
Beatrice Schwarz ◽  
Dieter Cech ◽  
Antonín Holý ◽  
Jan Škoda
Keyword(s):  
Enzymatic Degradation ◽  
Allyl Bromide ◽  
Antibacterial Effect ◽  
Structural Features ◽  
Enzymatic Cleavage ◽  
Cell Free Extract ◽  
Antibacterial Effects ◽  
E Coli ◽  
Sugar Moiety ◽  
Derivatives Of

Reaction of perbenzoylated aldopentafuranosyl derivatives of uracil with fluorine in acetic acid afforded perbenzoylated 5-fluorouracil nucleosides. Their methanolysis gave the following free nucleosides of 5-fluorouracil: β-D-ribofuranoside (Id), 2-deoxy-β-D-ribofuranoside (IId), their enantiomers VIII and IX, α-D-ribofuranoside (XIII), 2-deoxy-α-D-ribofuranoside (XV), β-D-arabinofuranoside (IV) and its L-enantiomer X, β-D-xylofuranoside (V) and its α-D-anomer XI, α-L-lyxofuranoside (VI) and 2-deoxy-α-L-lyxofuranoside (VII) and the enantiomers of the latter two compounds, XII and XIV, respectively. Analogously were obtained 5-deoxy-β-D-ribofuranoside (III), β-D-ribopyranoside (XVI) and 1-(S)-(2,3-dihydroxypropyl)-5-fluorouracil (XVIIc). 1-Allyl-5-fluorouracil (XVIII) was prepared by reaction of allyl bromide with 2,4-bis(trimethylsilyloxy)-5-fluoropyrimidine. The cell-free extract from Escherichia coli cleaves all the 5-fluorouracil nucleosides in which the nucleoside carbon atom has the R-configuration and the 3'-hydroxyl of the sugar moiety is in trans-relation to the base. Compounds which have not these structural features are resistant. Besides nucleosides which on enzymatic cleavage afford 5-fluorouracil, also the non-cleavable 1-(2-deoxy-β-L-ribofuranosyl)-5-fluorouracil (IX), 1-(2-deoxy-α-D-ribofuranosyl)-5-fluorouracil (XV) and 1-(2-deoxy-α-D-lyxofuranosyl)-5-fluorouracil (XIV) exhibit an antibacterial effect towards E. coli (ID50 1.0-2.5 . 10-5 M). This effect can be reversed by 2'-deoxyuridine but not by thymidine.

scholarly journals Uji Efek Antibakteri Chromodoris dianae terhadap Bakteri Escherichia coli dan Staphylococcus aureus

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Eflentina Kipimbob ◽  
Robert Bara ◽  
Pemsi M. Wowor ◽  
Jimmy Posangi
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Experimental Study ◽  
Antibacterial Effect ◽  
Inhibition Zone ◽  
Positive Control ◽  
Antibacterial Effects ◽  
E Coli ◽  
Mean Diameter ◽  
The Mean

Abstract: This study was aimed to evaluate the antibacterial effect of Chromodoris dianae on E.coli and S. aureus. This was an experimental study. Samples of Chromodoris dianae was taken from Bunaken waters by diving. Extract of Chromodoris dianae was obtained by using maceration technique with 96% etanol. Antibacterial activity of this extract was tested by using the Kirby-Bauer method. The results showed that the mean diameter of the inhibition zone of E. coli was 22.3±1.5 mm and of S. aureus was 23.0±1.0 mm; both were were less than of ciprofloxacin as the positive control repeated for three times. Conclusionn: Chromodoris dianae has antibacterial effects on the growth of Escherichia coli and Staphylococcus aureus.Keywords: Chromodoris dianae, Staphylococcus aureus, Escherichia coli Abstrak: Penelitian ini bertujuan untuk melihat adanya efek antibakteri dari Chromodoris dianae terhadap bakteri E.coli dan S. aureus. Jenis penelitian ialah eksperimental. Sampel Chromodoris dianae diambil dari perairan Bunaken dengan cara menyelam. Ekstrak Chromodoris dianae dibuat dengan cara maserasi menggunakan etanol 96%. Pengujian aktivitas antibakteri dilakukan dengan menggunakan metode Kirby-Bauer. Hasil penelitian menunjukkan adanya zona hambat terhadap E. coli dan S. aureus dengan rerata diameter 22,3±1,5 mm dan 23,0±1,0 mm, yang lebih kecil daripada rerata diameter kontrol positif siprofloksasin pada tiga kali pengulangan. Simpulan: Chromodoris dianae memiliki efek antibakteri terhadap pertumbuhan bakteri Staphylococcus aureus dan Escherichia coli.Kata kunci: Chromodoris dianae, Staphylococcus aureus, Escherichia coli

Antibacterial effect of verjuice against food-borne pathogens

2019 ◽  
Vol 121 (10) ◽  
pp. 2265-2276
Author(s):  
Nilgün Öncül ◽  
Şeniz Karabiyikli
Keyword(s):  
Food Safety ◽  
Antimicrobial Agents ◽  
Antibacterial Effect ◽  
Antibacterial Effects ◽  
Content Type ◽  
E Coli ◽  
Food Borne Pathogens ◽  
Food Borne ◽  
Resistant Microorganism

Purpose Nowadays, natural products are preferred for food safety and preservation due to the demand of consumers. The industrial methods which have been in use for a long period of time have had an adverse impact on organoleptic properties of foods or on human health. The purpose of this paper is to investigate the antibacterial effects of unripe grape products on natural and inoculated micro-flora of lettuce as an alternative functional and natural antibacterial agent for consumers and food industry. Design/methodology/approach The antibacterial effects of products on initial micro-flora of lettuce were detected. The lettuce samples were treated with products for different treatment times (0, 5 and 10 min). The antibacterial effects of products against inoculated micro-flora on lettuce were obtained. Lettuce samples were separately inoculated with food-borne pathogens (~4 log CFU/g) and treated with products for the same treatment periods. Findings Unripe grape products decreased the initial micro-flora by approximately 1 log CFU/g in 5 min. Unripe grape products dramatically inhibited the inoculated E. coli on lettuce samples right after the treatment. Majority of the unripe grape products decreased the number of S. Typhimurium and L. monocytogenes to an undetectable level in 5 min. S. aureus was the most resistant microorganism among the tested cultures. It was concluded based on the conspicuous results on the inhibition of E. coli, S. Typhimurium and L. monocytogenes that unripe grape products can be considered as natural antimicrobial agents for food safety. Originality/value This study is also valuable since it enables the in situ testing of the potential usage of unripe grape products against food-borne pathogens.

β-Lactamase inactivation by mechanism-based reagents

1980 ◽  
Vol 289 (1036) ◽  
pp. 309-319 ◽  
Keyword(s):  
Enzyme Activity ◽  
Mode Of Action ◽  
Structural Features ◽  
Irreversible Loss ◽  
E Coli ◽  
Mechanistic Pathway ◽  
Hydrolysis Of ◽  
Derivatives Of ◽  
Enzyme Intermediate ◽  
Acyl Derivatives

The mechanistic pathway followed by the E. coli R TEM ß-lactamase has been studied with a view to clarifying the mode of action of a number of recently discovered inactivators of the enzyme. There is clear evidence that the ß-lactamase-catalysed hydrolysis of the 7-a-methoxycephem, cefoxitin, proceeds via an acyl-enzyme intermediate. An analysis of the inactivation reactions of all the known ß-lactam derivatives that result in irreversible loss of enzyme activity permits the identification of three structural features required for a ß-lactamase inactivator. The application of these principles suggests a new group of mechanism-based inactivators of the enzyme: the sulphones of N -acyl derivatives of 6-ß-aminopenicillanic acid that are themselves poor substrates for the enzyme. These sulphones are powerful inactivators of the ß-lactamase.

Preparation of analogues of cytosine and 2-pyrimidinone nucleosides and their effect on bacterial (Escherichia coli A 19) cytidine aminohydrolase

1985 ◽  
Vol 50 (2) ◽  
pp. 393-417 ◽  
Author(s):  
Antonín Holý ◽  
Anita Ludziša ◽  
Ivan Votruba ◽  
Kateřina Šedivá ◽  
Helmut Pischel
Keyword(s):  
Hydroxy Group ◽  
Necessary Conditions ◽  
Heterocyclic System ◽  
Similar Type ◽  
Open Chain ◽  
Heterocyclic Base ◽  
Basic Character ◽  
E Coli ◽  
Sugar Moiety ◽  
Derivatives Of

The set of compounds investigated as substrates and inhibitors of bacterial cytidine aminohydrolase (EC 3.5.4.5) consists of cytidine analogues modified in the heterocyclic base or the sugar moiety and analogues of the similar type derived from l-(β-D-ribofuranosyl)-2-pyrimidone (I) and its isomers. The latter group of compounds includes also open-chain derivatives of neutral and acidic character. These compounds were prepared by novel synthetic procedures. Minimum necessary conditions for the structure of an inhibitor of cytidine aminohydrolase from E. coli A 19 include: a heterocyclic system containing an Rf-N-CO-N(H) fragment of a basic character in which Rf denotes a β-D-aldopentafuranoside with a 3-hydroxy group of ribo-configuration; the 5-hydroxy group of the sugar moiety may bear a substituent, except a phosphomonoester function. The heterocyclic base may also bear substituents in positions other than α to the nucleoside bond which do not reduce substantially the basicity of the system and do not change the conformation of the nucleoside molecule.

The Assessment of Chitosan Solutions Effects on Bacterial Strains

2018 ◽  
Vol 69 (6) ◽  
pp. 1485-1488
Author(s):  
Marioara Nicoleta Filimon ◽  
Roxana Popescu ◽  
Adrian Sinitean ◽  
Paula Maniu ◽  
Gabi Dumitrescu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Streptococcus Pyogenes ◽  
Legionella Pneumophila ◽  
Antibacterial Effect ◽  
Antibacterial Properties ◽  
Bacterial Strains ◽  
Antibacterial Effects ◽  
E Coli ◽  
Bacterial Cell Viability ◽  
And Staphylococcus Aureus

The interest in the antimicrobial actions of chitosan is due to its multiple properties and effects. The aim of the study was to assess the potential antibacterial effects of chitosan applied on 7 bacterial strains: Escherichia coli, Streptococcus pyogenes, Pseudomonas aeruginosa, Enterococcus faecalis, Clostridium perfringens, Legionella pneumophila and Staphylococcus aureus. Six different concentrations of chitosan were dissolved in 1% acetic acid, following two working protocols (Kirby-Bauer method and testing for bacterial cell viability). The sensitivity of tested bacterial strains following the effect of exposure to chitosan decreased as follows: E. coli] L. pneumophila] S. aureus] S. pyogenes] C. perfringens] P. aeruginosa] E. faecalis. The inhibition rates for the bacterial strains E. faecalis, S. pyogenes and S. aureus highlighted again the strong antibacterial properties of this product. Conclude that the chitosan presents a different antibacterial effect against several bacterial strains of interest directly with the employed concentrations.

Structure-Activity Relationship and Antimicrobial Evaluation of N-Phenylpyrazole Curcumin Derivatives

2020 ◽  
Vol 16 (4) ◽  
pp. 481-488
Author(s):  
Heli Sanghvi ◽  
Satyendra Mishra
Keyword(s):  
Antibacterial Activity ◽  
Gram Negative Bacteria ◽  
Pyrazole Derivatives ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Curcumin Derivatives ◽  
Structure Activity ◽  
Electron Donating Groups ◽  
Derivatives Of

Background: Curcumin, one of the most important pharmacologically significant natural products, has gained significant consideration among scientists for decades since its multipharmacological activities. 1, 3-Dicarbonyl moiety of curcumin was found to be accountable for the rapid degradation of curcumin molecule. The aim of present work is to replace 1, 3-dicarbonyl moiety of curcumin by pyrazole and phenylpyrazole derivatives with a view to improving its stability and to investigate the role of substitution in N-phenylpyrazole curcumin on its antibacterial activity against both Gram-positive as well as Gram-negative bacteria. Methods: Pyrazole derivatives of curcumin were prepared by heating curcumin with phenyhydrazine/ substituted phenyhydrazine derivatives in AcOH. The residue was purified by silica gel column chromatography. Structures of purified compounds were confirmed by 1H NMR and Mass spectroscopy. The synthesized compounds were evaluated for their antibacterial activity by the microdilution broth susceptibility test method against gram positive (S. aureus) and gram negative (E. coli). Results: Effects of substitution in N-phenylpyrazole curcumin derivatives against S. aureus and E. coli were studied. The most active N-(3-Nitrophenylpyrazole) curcumin (12) exhibits twenty-fold more potency against S. aureus (MIC: 10μg/mL)) and N-(2-Fluoroophenylpyrazole) curcumin (5) fivefold more potency against E. coli (MIC; 50 μg/mL) than N-phenylpyrazole curcumin (4). Whereas, a remarkable decline in anti-bacterial activity against S. aureus and E. coli was observed when electron donating groups were incorporated in N-phenylpyrazole curcumin (4). Comparative studies of synthesized compounds suggest the effects of electron withdrawing and electron donating groups on unsubstituted phenylpyrazole curcumin (4). Conclusion: The structure-activity relationship (SAR) results indicated that the electron withdrawing and electron donating at N-phenylpyrazole curcumin played key roles for their bacterial inhibitory effects. The results of the antibacterial evaluation showed that the synthesized pyrazole derivatives of curcumin displayed moderate to very high activity in S. aureus. In conclusion, the series of novel curcumin derivatives were designed, synthesized and tested for their antibacterial activities against S. aureus and E. coli. Among them, N-(3-Nitrophenylpyrazole curcumin; 12) was most active against S. aureus (Gram-positive) and N-(2-Fluoroophenylpyrazole) curcumin (5) against E. coli (Gram-negative) bacteria.

Gold Nanoparticle Biosynthesis by E. coli and Conjugation with Streptomycin and Evaluation of its Antibacterial Effect

2014 ◽  
Vol 10 (4) ◽  
pp. 553-561 ◽  
Author(s):  
Samaneh Mazdeh ◽  
Hossein Motamedi ◽  
Azim Khiavi ◽  
Mohammad Mehrabi
Keyword(s):  
Gold Nanoparticle ◽  
Antibacterial Effect ◽  
E Coli ◽  
Nanoparticle Biosynthesis

scholarly journals Synergistic antibacterial combination of Lavandula latifolia Medik. essential oil with camphor

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Nursenem Karaca ◽  
Görkem Şener ◽  
Betül Demirci ◽  
Fatih Demirci
Keyword(s):  
Staphylococcus Aureus ◽  
Essential Oil ◽  
Antibacterial Effect ◽  
Synergistic Effects ◽  
Pharmaceutical Formulations ◽  
Human Pathogens ◽  
Broth Microdilution ◽  
Antibacterial Effects ◽  
Lavandula Latifolia

AbstractCombination of various compounds and essential oils for pharmaceutical formulations withdraw attention. In this present study, it was aimed to evaluate the in vitro potential synergistic antibacterial effect of Lavandula latifolia (spike lavender) essential oil with camphor by using the checkerboard method against the human pathogens; Staphylococcus aureus and Listeria monocytogenes. Pharmacopoeia quality L. latifolia essential oil and racemic camphor were analyzed and verified by GC-FID and GC/MS, simultaneously. In vitro antibacterial activity of essential oil and camphor (MIC range: 0.16–20 mg/mL) and standard antimicrobial clarithromycin (MIC range: 0.125–16 μg/mL) were carried out by broth microdilution against S. aureus and L. monocytogenes standard strains, respectively. Resulting antibacterial effects were evaluated for their fractional inhibitory concentrations (FICs) as antagonistic, additive and synergistic effects. The analytical results showed that the major component of essential oil was linalool (45.2%) and 1,8-cineole (25.6%). Antibacterial effects of essential oil were determined as MIC 1.25–5 mg/mL. As a result of the experiments, L. latifolia essential oil–camphor combinations were identified as “synergistic (FIC ≤ 0.5), and additive (0.5 < FIC ≤ 1)” in the respective combinations, suggesting further evaluation for formulations for potential antimicrobial applications in food and pharmaceuticals.

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 A genetically detoxified derivative of heat-labile Escherichia coli enterotoxin induces neutralizing antibodies against the A subunit.

1994 ◽  
Vol 180 (6) ◽  
pp. 2147-2153 ◽  
Author(s):  
M Pizza ◽  
M R Fontana ◽  
M M Giuliani ◽  
M Domenighini ◽  
C Magagnoli ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Cholera Toxin ◽  
Neutralizing Antibodies ◽  
Site Directed Mutagenesis ◽  
Directed Mutagenesis ◽  
E Coli ◽  
Heat Labile ◽  
A Subunit ◽  
Adp Ribosyltransferase ◽  
Derivatives Of

Escherichia coli enterotoxin (LT) and the homologous cholera toxin (CT) are A-B toxins that cause travelers' diarrhea and cholera, respectively. So far, experimental live and killed vaccines against these diseases have been developed using only the nontoxic B portion of these toxins. The enzymatically active A subunit has not been used because it is responsible for the toxicity and it is reported to induce a negligible titer of toxin neutralizing antibodies. We used site-directed mutagenesis to inactivate the ADP-ribosyltransferase activity of the A subunit and obtained nontoxic derivatives of LT that elicited a good titer of neutralizing antibodies recognizing the A subunit. These LT mutants and equivalent mutants of CT may be used to improve live and killed vaccines against cholera and enterotoxinogenic E. coli.

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