Coprinol, a New Antibiotic Cuparane from a Coprinus Species

2001 ◽  
Vol 56 (1-2) ◽  
pp. 31-34 ◽  
Author(s):  
Martin Johansson ◽  
Olov Sterner ◽  
Harald Labischinski ◽  
Timm Anke

Abstract Coprinol, a new antibacterial cuparane, was isolated from fermentations of a Coprinus sp. Its biological activities were investigated and its structure was elucidated by spectroscopic methods. The new antibiotic exhibited activitiy against multidrug-resistant Gram -positive bacteria in vitro. Two derivatives were synthesized and their activities compared to the parent compound.

2001 ◽  
Vol 45 (5) ◽  
pp. 1422-1430 ◽  
Author(s):  
Suzanne Chamberland ◽  
Johanne Blais ◽  
Monica Hoang ◽  
Cynthia Dinh ◽  
Dylan Cotter ◽  
...  

ABSTRACT RWJ-54428 (MC-02,479) is a new cephalosporin with a high level of activity against gram-positive bacteria. In a broth microdilution susceptibility test against methicillin-resistant Staphylococcus aureus (MRSA), RWJ-54428 was as active as vancomycin, with an MIC at which 90% of isolates are inhibited (MIC90) of 2 μg/ml. For coagulase-negative staphylococci, RWJ-54428 was 32 times more active than imipenem, with an MIC90 of 2 μg/ml. RWJ-54428 was active against S. aureus, Staphylococcus epidermidis, and Staphylococcus haemolyticus isolates with reduced susceptibility to glycopeptides (RWJ-54428 MIC range, ≤0.0625 to 1 μg/ml). RWJ-54428 was eight times more potent than methicillin and cefotaxime against methicillin-susceptible S. aureus (MIC90, 0.5 μg/ml). For ampicillin-susceptible Enterococcus faecalis (including vancomycin-resistant and high-level aminoglycoside-resistant strains), RWJ-54428 had an MIC90 of 0.125 μg/ml. RWJ-54428 was also active against Enterococcus faecium, including vancomycin-, gentamicin-, and ciprofloxacin-resistant strains. The potency against enterococci correlated with ampicillin susceptibility; RWJ-54428 MICs ranged between ≤0.0625 and 1 μg/ml for ampicillin-susceptible strains and 0.125 and 8 μg/ml for ampicillin-resistant strains. RWJ-54428 was more active than penicillin G and cefotaxime against penicillin-resistant, -intermediate, and -susceptible strains ofStreptococcus pneumoniae (MIC90s, 0.25, 0.125, and ≤0.0625 μg/ml, respectively). RWJ-54428 was only marginally active against most gram-negative bacteria; however, significant activity was observed against Haemophilus influenzae andMoraxella catarrhalis (MIC90s, 0.25 and 0.5 μg/ml, respectively). This survey of the susceptibilities of more than 1,000 multidrug-resistant gram-positive isolates to RWJ-54428 indicates that this new cephalosporin has the potential to be useful in the treatment of infections due to gram-positive bacteria, including strains resistant to currently available antimicrobials.


2020 ◽  
Vol 10 (5) ◽  
pp. 274-292
Author(s):  
Rohit Kumar ◽  
Sushil Kumar ◽  
Mohammad Asif Khan

Recently a series of Schiff bases of diphenylamine derivatives have been synthesized and evaluated in vitro for their antibacterial activity against pathogenic both Gram-positive bacteria B. subtitles and Gram-negative bacteria E. coli using ciprofloxacin as standard drug at conc. of 50 μg/ml and 100 μg/ml. Literature review revels that chalcones possesses various biological activities like antimicrobial, antiviral, anti-inflammatory, anticancer and sedative etc. Therefore the present study was designed on synthesis and pharmacological evaluation of 2-(4-(3 (Substituted Phenyl) Acryloyl) Phenoxy)-N, N Diphenylacetamides. Target compound was synthesized by reaction of chloroacetylchloride with diphenylamine to afford 2-chloro-N, N-diphenylacetamide which further by reaction with substituted Chalcones and characterized following recrystallization and evaluated for anti-microbial potential through cup-diffusion method. In results, the target compounds were tested for activity against B. Subtilis, E.Coli and C. albicans. The chalcones having the lipophilic 4-chloro group (RKCT2) showed the greatest antimicrobial activity (zone of inhibition 20 & 22 mm against. B. subtilis, E. Coli, C. Albicans respectively. It suggests further researchers to go through anti-microbial evaluations against a more varieties of bacteria and fungi. Keywords: Schiff bases of diphenylamine derivatives, antibacterial activity, Gram-positive bacteria, 2-(4-(3 (Substituted Phenyl) Acryloyl) Phenoxy)-N, N Diphenylacetamides


1997 ◽  
Vol 41 (6) ◽  
pp. 1260-1268 ◽  
Author(s):  
M Tanaka ◽  
M Hohmura ◽  
T Nishi ◽  
K Sato ◽  
I Hayakawa

The in vitro antibacterial activity of DU-6681a, a parent compound of DZ-2640, against gram-positive and -negative bacteria was compared with those of penems and cephalosporins currently available. MICs at which 90% of the isolates are inhibited (MIC90s) of the compound for clinical isolates of methicillin-susceptible and -resistant Staphylococcus aureus and Staphylococcus epidermidis, including methicillin-susceptible and -resistant strains, were 0.10, 25, and 12.5 microg/ml, respectively. DU-6681a inhibited the growth of all strains of Streptococcus pyogenes and of penicillin-susceptible and -insusceptible Streptococcus pneumoniae at 0.006, 0.025, and 0.20 microg/ml, respectively, and MIC90s of the compound were 6.25 and >100 microg/ml for Enterococcus faecalis and Enterococcus faecium, respectively. MIC90s of DU-6681a were 0.20, 0.10, and 0.025 microg/ml for Haemophilus influenzae, Moraxella catarrhalis, and Neisseria gonorrhoeae, respectively. For Pseudomonas aeruginosa, the MIC50 and MIC90 of DU-6681a were 25 and 50 microg/ml, respectively. DU-6681a activity was not affected by different media, varied inoculum size (10(4) to 10(7) CFU), or the addition of human serum but was decreased under acidic conditions against gram-negative bacteria, under alkaline conditions against gram-positive bacteria, and in human urine, as was the activity of the other antibiotics tested. The frequency of spontaneous resistance to DU-6681a was less than or equal to those of the reference compounds. Time-kill curve studies demonstrated the bactericidal action of DU-6681a against S. aureus, S. pneumoniae, Escherichia coli, and H. influenzae.


2003 ◽  
Vol 47 (5) ◽  
pp. 1689-1693 ◽  
Author(s):  
Ian A. Critchley ◽  
Renée S. Blosser-Middleton ◽  
Mark E. Jones ◽  
Clyde Thornsberry ◽  
Daniel F. Sahm ◽  
...  

ABSTRACT The activity of daptomycin was assessed by using 6,973 gram-positive bacteria isolated at 50 United States hospitals in 2000 and 2001. Among the isolates of Streptococcus pneumoniae (n = 1,163) collected, the rate of penicillin resistance was 16.1%; rates of oxacillin resistance among Staphylococcus aureus isolates (n = 1,018) and vancomycin resistance among Enterococcus faecium isolates (n = 368) were 30.0 and 59.5%, respectively. Multidrug-resistant (MDR) phenotypes (isolates resistant to three or more different chemical classes of antimicrobial agents) accounted for 14.2% of S. pneumoniae isolates, 27.1% of S. aureus isolates, and 58.4% of E. faecium isolates. For all gram-positive species tested, MICs at which 90% of the isolates tested were inhibited (MIC90s) and MIC ranges for directed-spectrum agents (daptomycin, quinupristin-dalfopristin, and linezolid) were identical or highly similar for isolates susceptible or resistant to other agents or MDR. Daptomycin had a MIC90 of 0.12 μg/ml for both penicillin-susceptible and -resistant isolates of S. pneumoniae. Against oxacillin-resistant S. aureus daptomycin had a MIC90 of 0.5 μg/ml, and it had a MIC90 of 4 μg/ml against both vancomycin-susceptible and -resistant E. faecium. The MIC90s for daptomycin and other directed-spectrum agents were unaffected by the regional or anatomical origin of isolates or patient demographic parameters (patient age, gender, and inpatient or outpatient care). Our results confirm the gram-positive spectrum of activity of daptomycin and that its activity is independent of susceptibility or resistance to commonly prescribed and tested antimicrobial agents. This study may serve as a baseline to monitor future changes in the susceptibility of gram-positive species to daptomycin following its introduction into clinical use.


2010 ◽  
Vol 54 (9) ◽  
pp. 3974-3977 ◽  
Author(s):  
Michelle M. Butler ◽  
John D. Williams ◽  
Norton P. Peet ◽  
Donald T. Moir ◽  
Rekha G. Panchal ◽  
...  

ABSTRACT Antimicrobial susceptibilities of 233 Gram-positive and 180 Gram-negative strains to two novel bis-indoles were evaluated. Both compounds were potent inhibitors of Gram-positive bacteria, with MIC90 values of 0.004 to 0.5 μg/ml. One bis-indole, MBX 1162, exhibited potent activity against all Gram-negative strains, with MIC90 values of 0.12 to 4 μg/ml, even against high-level-resistant pathogens, and compared favorably to all comparator antibiotics. The bis-indole compounds show promise for the treatment of multidrug-resistant clinical pathogens.


Marine Drugs ◽  
2018 ◽  
Vol 16 (8) ◽  
pp. 289 ◽  
Author(s):  
Decha Kumla ◽  
José Pereira ◽  
Tida Dethoup ◽  
Luis Gales ◽  
Joana Freitas-Silva ◽  
...  

A previously unreported chromene derivative, 1-hydroxy-12-methoxycitromycin (1c), and four previously undescribed chromone derivatives, including pyanochromone (3b), spirofuranochromone (4), 7-hydroxy-6-methoxy-4-oxo-3-[(1E)-3-oxobut-1-en-1-yl]-4H-chromene-5-carboxylic acid (5), a pyranochromone dimer (6) were isolated, together with thirteen known compounds: β-sitostenone, ergosterol 5,8-endoperoxide, citromycin (1a), 12-methoxycitromycin (1b), myxotrichin D (1d), 12-methoxycitromycetin (1e), anhydrofulvic acid (2a), myxotrichin C (2b), penialidin D (2c), penialidin F (3a), SPF-3059-30 (7), GKK1032B (8) and secalonic acid A (9), from cultures of the marine sponge- associated fungus Penicillium erubescens KUFA0220. Compounds 1a–e, 2a, 3a, 4, 7–9, were tested for their antibacterial activity against Gram-positive and Gram-negative reference and multidrug-resistant strains isolated from the environment. Only 8 exhibited an in vitro growth inhibition of all Gram-positive bacteria whereas 9 showed growth inhibition of methicillin-resistant Staphyllococus aureus (MRSA). None of the compounds were active against Gram-negative bacteria tested.


2020 ◽  
Vol 16 (8) ◽  
pp. 1112-1123
Author(s):  
Othman Hamed ◽  
Oswa Fares ◽  
Shaima Taleeb ◽  
Ghaleb Adwan ◽  
Haythem Saadeh ◽  
...  

Background: Curcumin is a safe, versatile natural product with unlimited number of biological activities and a precursor for various heterocyclic compounds. Objective: The present study was aimed to the development of a curcumin based antimicrobial reagent with high potency against gram-positive and gram-negative bacteria. Methods: Herein we report a simple and convenient one step method for synthesizing a series of 1,4-benzodiazepines via condensation cyclization reaction between curcumin and various 1,2- phenylenediamine in refluxed ethanol. Results: A series of new 1,4-benzodiazepins were synthesized and their structures were supported by FT-IR, 1H NMR, 13C NMR, and mass spectral analysis. Synthesized 1,4-benzodiazepins were evaluated for their in vitro antimicrobial activity against gram positive (S. aureus and S. epidermidis) and gram negative (E. coli and P. aeruginosa) bacteria. They exhibited low to high potency against the tested organisms. In particular, dichlorinated 1,4-benzodiazepine 9 exhibited a remarkable potency against the gram-positive bacteria S. aureus (MIC: 3.125 μg mL-1, MBC: 12 μg mL-1). It showed a higher potency than most of the tested reference drugs. Compound 9 showed the medium activity against E. coli. Genotoxic study revealed that, benzodiazepines 9 attacked the DNA of E. coli strains and damaged it. The potency of compound 9, could be attributed to the multiple chlorine atoms present on the aromatic ring. Conclusion: Some of the synthesized curcumin based benzodiazepines showed excellent potency against gram positive bacteria. These benzodiazepines could be a great candidate as a future antimicrobial agent.


Antibiotics ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 36 ◽  
Author(s):  
Andrea Vila Domínguez ◽  
Rafael Ayerbe Algaba ◽  
Andrea Miró Canturri ◽  
Ángel Rodríguez Villodres ◽  
Younes Smani

Due to the emergence of antimicrobial resistance, new alternative therapies are needed. Silver was used to treat bacterial infections since antiquity due to its known antimicrobial properties. Here, we aimed to evaluate the in vitro activity of colloidal silver (CS) against multidrug-resistant (MDR) Gram-negative and Gram-positive bacteria. A total of 270 strains (Acinetobacter baumannii (n = 45), Pseudomonas aeruginosa (n = 25), Escherichia coli (n = 79), Klebsiella pneumoniae (n = 58)], Staphylococcus aureus (n = 34), Staphylococcus epidermidis (n = 14), and Enterococcus species (n = 15)) were used. The minimal inhibitory concentration (MIC) of CS was determined for all strains by using microdilution assay, and time–kill curve assays of representative reference and MDR strains of these bacteria were performed. Membrane permeation and bacterial reactive oxygen species (ROS) production were determined in presence of CS. CS MIC90 was 4–8 mg/L for all strains. CS was bactericidal, during 24 h, at 1× and 2× MIC against Gram-negative bacteria, and at 2× MIC against Gram-positive bacteria, and it did not affect their membrane permeabilization. Furthermore, we found that CS significantly increased the ROS production in Gram-negative with respect to Gram-positive bacteria at 24 h of incubation. Altogether, these results suggest that CS could be an effective treatment for infections caused by MDR Gram-negative and Gram-positive bacteria.


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