scholarly journals Properties of β-lactamases produced by three species of mycobacteria

1968 ◽  
Vol 107 (5) ◽  
pp. 675-682 ◽  
Author(s):  
J. E. Kasik ◽  
Lin Peacham
Keyword(s):  
Mycobacterium Smegmatis ◽  
Extracellular Fluid ◽  
Gram Negative Bacteria ◽  
Cephalosporin C ◽  
Gram Positive ◽  
Intact Cells ◽  
Gram Negative ◽  
Substrate Specificities ◽  
High Concentrations ◽  
Derivatives Of

1. Mycobacterium smegmatis (N.C.T.C. 8158), M. fortuitum and M. phlei (MPI) produce a constitutive β-lactamase that has penicillinase and cephalosporinase activity. 2. The β-lactamases of these three species of acid-fast bacteria were mainly cell-bound, only small amounts of activity being liberated into the extracellular fluid. The total β-lactamase activity of these mycobacteria was much lower than that of certain Gram-positive organisms, but comparable with that reported for species of Gram-negative bacteria. 3. The β-lactamases of intact cells of the mycobacteria were not freely accessible to any of the substrates tested, but the apparent crypticity factor to benzylpenicillin was greater than that to cephaloridine and cephalosporin C. 4. Attempts to induce β-lactamase activity in M. smegmatis and M. phlei failed even with high concentrations of inducer. 5. The β-lactamases obtained from the three species of mycobacteria showed different substrate specificities, including different relative activities as cephalosporinases and penicillinases respectively. 6. Certain derivatives of 6-aminopenicillanic acid and 7-aminocephalosporanic acid were found to be resistant to hydrolysis by β-lactamases of M. smegmatis and M. fortuitum. 7. The β-lactamase of M. smegmatis was competitively inhibited by a number of β-lactamase-resistant derivatives of 6-aminopenicillanic acid, but not by similar derivatives of 7-aminocephalosporanic acid.

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.

scholarly journals Improved Derivatives of Bactenecin, a Cyclic Dodecameric Antimicrobial Cationic Peptide

1999 ◽  
Vol 43 (5) ◽  
pp. 1274-1276 ◽  
Author(s):  
Manhong Wu ◽  
Robert E. W. Hancock
Keyword(s):  
Amino Acid ◽  
Antimicrobial Peptide ◽  
Tryptophan Residue ◽  
Gram Negative Bacteria ◽  
Cationic Peptide ◽  
Gram Positive ◽  
Antimicrobial Spectrum ◽  
Gram Negative ◽  
Derivatives Of

ABSTRACT Both linear and cyclic derivatives of the cyclic 12-amino-acid antimicrobial peptide bactenecin were designed based on optimization of amphipathicity and charge location. In general, increasing the number of positive charges at the N and C termini and adding an extra tryptophan residue in the loop not only increased the activities against both gram-positive and gram-negative bacteria but also broadened the antimicrobial spectrum.

scholarly journals Synthesis and Evaluation of Antimicrobial Activity of Nitrones from Derivatives of Aryl-Substituted Dihydroisoquinoline

2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Mouna Bouzid ◽  
Raed Abdennabi ◽  
Mohamed Damak ◽  
Majed Kammoun
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
High Purity ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Derivatives Of

This paper describes the synthesis of a series of dihydroisoquinoline nitrones by isomerization of the corresponding oxaziridines. Nitrones4a–cwere obtained in excellent yields and high purity by a simple and effective method from the isomerization of oxaziridines. The synthesized compounds were also evaluated for their antibacterial activity against Gram-positive and Gram-negative bacteria and fungus.

scholarly journals Synthesis and Biologically Important of 2-Mercaptobenthiazole (MBT)-Clubbed Chalcone Derivatives

2016 ◽  
Vol 63 ◽  
pp. 83-89
Author(s):  
Falguni Bhabhor ◽  
K. Satish ◽  
Hiren Variya ◽  
Vikram Panchal
Keyword(s):  
Elemental Analysis ◽  
Antimicrobial Properties ◽  
Spectral Characterization ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Chalcone Derivatives ◽  
H Nmr ◽  
Derivatives Of

In this present work base catalyzed method used for formation of Chalcone of (E)-4-(3-(4-hydroxyphenyl) acryloyl)-5-methyl-2(p-tolyl)-1H-pyrazol-3(2H)-one (II) reacted with derivatives of S-benzo [d] thiol-2yl-2-chloroethanethioate (Ia-f) resulted in formation of corresponding derivatives of (E)-S-benzo [d] thiazol-2-yl 2-(4-(3-(5-methyl-3oxo-2(p-tolyl)-2,3-dihydro-1H-pyrazol-4-yl)-3-oxoprop-1-en-1-yl) phenoxy) etanethioate (IIIa-f) was confirmed by spectral characterization such as IR,1H NMR, LC-MS and elemental analysis. The compounds were screened for their antimicrobial properties against a broad panel Gram-positive and Gram-negative bacteria as well as fungi.

Antibacterial activity of high concentrations of carvedilol against Gram-positive and Gram-negative bacteria

2018 ◽  
Vol 51 (3) ◽  
pp. 458-467 ◽  
Author(s):  
Katarzyna Zawadzka ◽  
Przemysław Bernat ◽  
Aleksandra Felczak ◽  
Sylwia Różalska ◽  
Katarzyna Lisowska
Keyword(s):  
Antibacterial Activity ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
High Concentrations

Effect of Polypropylene Imine Nanocomposite on Gram-Positive and Gram-Negative Bacteria

2020 ◽  
Vol 18 (2) ◽  
pp. 115-120
Author(s):  
Bashir Mohammadpour ◽  
Mohammad A. Boshagh ◽  
Bagher Hayati ◽  
Leila Farhadi ◽  
Hajar Kashefi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotube ◽  
Staphylococcus Epidermidis ◽  
Mycobacterium Smegmatis ◽  
Pathogenic Bacteria ◽  
Gram Negative Bacteria ◽  
Low Carbon ◽  
Gram Positive ◽  
Gram Negative ◽  
Transmission Electron

Background: Nosocomial infection is a serious threat to hospitalized patients in healthcare when last-resort antibiotics do not act against pathogenic bacteria. Aims: The aim of this study was to study the effect of Polypropylene imine nanocomposite (PPI/CNT) on Gram-Positive and Gram-Negative bacteria. Methods: PPI/CNT component was produced. Surface morphology and structure of PPI/CNT were analyzed by Fourier-transform infrared (FTIR), Scanning Electron Microscopy (SAM) and Transmission Electron Microscopy (TEM). Minimum Inhibitory Concentration (MIC) of PPI/CNT was determined against various bacteria. Results: FTIR showed strong and wider peak binding molecules in the CNT/COOH and PPI/CNT component. PPI/CNT component was denser in comparison to low carbon nanotube according to SAM test. TEM images showed that carbon nanotube was covered by PPI dots. The lowest MIC concerns polymer particles for Staphylococcus epidermidis were 0.0025 μM/ml and Mycobacterium smegmatis 0.005 μM/ml. Conclusion: Our result indicated that PPI/CNT nanocomposite had good activity against Gram-positive and Gram-negative bacteria. Some of the gram-negative bacteria were tolerant up to highest concentration. With more investigations, it can be used as a new antibacterial component.

New synthesis of oxime-type beta-lactam antibiotics

1989 ◽  
Vol 54 (6) ◽  
pp. 1734-1745 ◽  
Author(s):  
Martin Mandel ◽  
Ludvík Novák ◽  
Miroslav Rajšner ◽  
Jiří Holubek ◽  
Vladislava Holá
Keyword(s):  
Phosphorus Pentachloride ◽  
Gram Negative Bacteria ◽  
Beta Lactam ◽  
Gram Positive ◽  
Gram Negative ◽  
Beta Lactam Antibiotics ◽  
New Synthesis ◽  
Trimethylsilyl Derivatives ◽  
Derivatives Of

Reaction of anhydrous acids II with phosphorus pentachloride afforded hydrochlorides of chlorides III which were used in acylations of N,O-bis(trimethylsilyl) derivatives of 6-aminopenicillanic and 7-aminodeacetoxycephalosporanic acid. Change of the (Z)-configuration of the alkoxyimino group during the synthesis was observed only in the methoxyimino series. The prepared penicillins IV are effective against gram-positive as well as gram-negative bacteria.

Rapid demonstration of septic or infectious arthritis due to Gram-negative bacteria

1992 ◽  
Vol 50 (1) ◽  
pp. 686-687
Author(s):  
Jacob S. Hanker ◽  
Paul R. Gross ◽  
Beverly L. Giammara
Keyword(s):  
Chronic Arthritis ◽  
Blood Cultures ◽  
Gram Negative Bacteria ◽  
Infectious Arthritis ◽  
Bacterial Arthritis ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Blood cultures are positive in approximately only 50 per cent of the patients with nongonococcal bacterial infectious arthritis and about 20 per cent of those with gonococcal arthritis. But the concept that gram-negative bacteria could be involved even in chronic arthritis is well-supported. Gram stains are more definitive in staphylococcal arthritis caused by gram-positive bacteria than in bacterial arthritis due to gram-negative bacteria. In the latter situation where gram-negative bacilli are the problem, Gram stains are helpful for 50% of the patients; they are only helpful for 25% of the patients, however, where gram-negative gonococci are the problem. In arthritis due to gram-positive Staphylococci. Gramstained smears are positive for 75% of the patients.

In-vitro Antioxidant and Antibacterial Activity of Methanolic Extract of Shorea robusta Gaertn. F. Resin

2016 ◽  
Vol 6 (4) ◽  
pp. 68
Author(s):  
Sushma Vashisht ◽  
Manish Pal Singh ◽  
Viney Chawla
Keyword(s):  
Antibacterial Activity ◽  
Methanolic Extract ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Disc Diffusion ◽  
Gram Positive ◽  
Gram Negative ◽  
Shorea Robusta ◽  
Dose Dependent ◽  
Resin Extract

The methanolic extract of the resin of Shorea robusta was subjected to investigate its antioxidant and antibacterial properties its utility in free radical mediated diseases including diabetic, cardiovascular, cancer etc. The methanol extract of the resin was tested for antioxidant activity using scavenging activity of DPPH (1,1-diphenyl-2-picrylhydrazil) radical method, reducing power by FeCl3 and antibacterial activity against gram positive and gram negative bacteria using disc diffusion method. The phytochemical screening considered the presence of triterpenoids, tannins and flavoniods. Overall, the plant extract is a source of natural antioxidants which might be helpful in preventing the progress of various oxidative stress mediated diseases including aging. The half inhibition concentration (IC50) of resin extract of Shorea robusta and ascorbic acid were 35.60 µg/ml and 31.91 µg/ml respectively. The resin extract exhibit a significant dose dependent inhibition of DPPH activity. Antibacterial activity was observed against gram positive and gram negative bacteria in dose dependent manner.Key Words: Shorea robusta, antioxidant, antibacterial, Disc-diffusion, DPPH.

Antibacterial activity of magnesium oxide nanoparticles prepared by Calcination method

2019 ◽  
Vol 10 (03) ◽  
Author(s):  
Elaf Ayad Kadhem ◽  
Miaad Hamzah Zghair ◽  
Sarah , Hussam H. Tizkam, Shoeb Alahmad Salih Mahdi ◽  
Hussam H. Tizkam ◽  
Shoeb Alahmad
Keyword(s):  
Antibacterial Activity ◽  
Magnesium Oxide ◽  
Diffusion Method ◽  
Oxide Nanoparticles ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Magnesium Oxide Nanoparticles ◽  
Agar Disc

magnesium oxide nanoparticles (MgO NPs) were prepared by simple wet chemical method using different calcination temperatures. The prepared NPs were characterized by Electrostatic Discharge (ESD), Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD). It demonstrates sharp intensive peak with the increase of crystallinty and increase of the size with varying morphologies with respect to increase of calcination temperature. Antibacterial studies were done on gram negative bacteria (E.coli) and gram positive bacteria (S.aureus) by agar disc diffusion method. The zones of inhibitions were found larger for gram positive bacteria than gram negative bacteria, this mean, antibacterial MgO NPs activity more active on gram positive bacteria than gram negative bacteria because of the structural differences. It was found that antibacterial activity of MgO NPs was found it has directly proportional with their concentration.

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