scholarly journals Siderophore Cephalosporin Cefiderocol Utilizes Ferric Iron Transporter Systems for Antibacterial Activity againstPseudomonas aeruginosa

2016 ◽  
pp. AAC.01405-16 ◽  
Author(s):  
Akinobu Ito ◽  
Toru Nishikawa ◽  
Shuhei Matsumoto ◽  
Hidenori Yoshizawa ◽  
Takafumi Sato ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Ferric Iron ◽  
Side Chain ◽  
Hydroxyl Groups ◽  
Intracellular Accumulation ◽  
Chelating Activity ◽  
Transporter Systems ◽  
Chelating Complex ◽  
Catechol Moiety

Cefiderocol (S-649266) is a novel parenteral siderophore cephalosporin conjugated with a catechol moiety at the 3rd-position side chain. Thein vitroactivity of cefiderocol againstPseudomonas aeruginosawas enhanced in the iron-depleted condition where that of ceftazidime was not affected. The monitoring of [Thiazole-14C]-cefiderocol revealed the increased intracellular accumulation of cefiderocol in theP. aeruginosacells incubated under iron-depleted condition compared with those incubated under iron-sufficient condition. Cefiderocol was shown to have potent chelating activity with ferric iron, and extracellular iron was efficiently transported intoP. aeruginosacells in the presence of cefiderocol as well as siderophores, while enhanced transport of extracellular ferric iron was not observed when one of the hydroxyl groups of catechol moiety of cefiderocol was substituted with a methoxy group. We conclude that cefiderocol forms a chelating complex with iron, which is actively transported intoP. aeruginosacells via iron transporters, resulting in potent antibacterial activity of cefiderocol againstP. aeruginosa.

scholarly journals Synthesis, Spectroscopic Characterization and Antibactrial Activities of Co(II) Complex of Ofloxacin Drug Mixed with Ascorbic Acid as secondary ligand

2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Ugochukwu Onyenze ◽  
I.E. Otuokere
Keyword(s):  
Ascorbic Acid ◽  
Antibacterial Activity ◽  
Melting Point ◽  
Spectroscopic Characterization ◽  
Diffusion Method ◽  
Hydroxyl Groups ◽  
Molecular Formula ◽  
Filter Paper Disc ◽  
Secondary Ligand

Ofloxacin is a quinolone antibiotic that is considered an efficient antibacterial drug with a broad spectrum of activity against anaerobic and aerobic bacteria and has strong antibacterial activity in vitro against many bacteria species by inhibiting their DNA-gyrase. In this study, the synthesis, physicochemical and spectroscopic characterization of Cobalt (II) metal complex with ofloxacin as primary ligand and ascorbic acid as the secondary ligand have been carried out. The complex was prepared by reflux method for four hours in methanol. The complex, with the molecular formula [Co(Ofl)(Asc)], was characterized by its color, solubility, melting point, FTIR, UV/Visible, 1H NMR, and 13C NMR spectroscopy. The color and the melting point suggest that complexation occurred. The Fourier Transform Infrared data for both the primary ligand (Ofl) and the secondary ligand (Asc) acted as tridentate ligands. Ofl coordinated to the Co(II) metal ion via the two carbonyl oxygen atoms and the oxygen atom of the hydroxyl group, whereas Asc coordinated to the metal through the carbonyl and enolic C-2 and C-3 hydroxyl groups. The electronic data suggests octahedral geometry for the complex. The ligands and the novel Co (II) complex were tested for in vitro antibacterial activity against gram-negative and gram-positive bacterial species using the filter paper disc agar diffusion method. Significant antibacterial activities were observed for the complex compared to the ligands. This research will aid in the development of more potent drugs that are resistant to organisms.

Incorporation of Fluorinated Pyridine in the Side Chain of 4-Aminoquinolines: Synthesis, Characterization and Antibacterial Activity

Drug Research ◽  
2017 ◽  
Vol 68 (01) ◽  
pp. 17-22 ◽  
Author(s):  
Reza Ranjbar-Karimi ◽  
Alireza Poorfreidoni
Keyword(s):  
Antibacterial Activity ◽  
Chemical Structure ◽  
Side Chain ◽  
Gram Negative Bacteria ◽  
Pyridine Derivatives ◽  
Positive Bacterium ◽  
Gram Positive ◽  
In Vitro Antibacterial Activity ◽  
Ft Ir

AbstractA series of hybrid of 4-aminoquinoline and fluorinated pyridine derivatives were synthesized and their chemical structure were confirmed by 19F-NMR, 1H-NMR, 13C-NMR and FT-IR. All compounds were tested against one Gram-positive and one Gram-negative bacteria to assess their in vitro antibacterial activity. Compounds 10a, 10b, 11a and 12b showed moderate antibacterial activity against Gram-positive bacterium, Staphylococcus aureus.

Oxidation studies on β-lactam antibiotics: In-vitro antimicrobial activity of the oxidized products of 3-heteroarylthiomethyl-ceph-3-ems

1991 ◽  
Vol 56 (11) ◽  
pp. 2362-2372 ◽  
Author(s):  
Rajeshwar Singh ◽  
Maya P. Singh ◽  
Ronald G. Micetich
Keyword(s):  
Hydrogen Peroxide ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Acetic Acid ◽  
Side Chain ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
In Vitro Antimicrobial Activity ◽  
Oxidized Products

Various products from the oxidation of 3-heteroarylthiomethyl-ceph-3-ems using m-chloroperbenzoic acid (m-CPBA) and hydrogen peroxide in acetic acid in varying stoichiometric ratios have been isolated, identified and their in vitro antimicrobial activity determined. The oxidized compounds with the 2-aminothiazol-4-yl-(Z)-2-methoxyiminoacetamido side chain showed better antibacterial activity against various Gram negative bacteria compared to the unoxidized compounds.

Structure─activity relationships in semi-synthetic penicillins

1971 ◽  
Vol 179 (1057) ◽  
pp. 357-367 ◽  
Keyword(s):  
Antibacterial Activity ◽  
Chemical Nature ◽  
Side Chain ◽  
Structural Variations ◽  
Present Survey ◽  
Structure Activity Relationships ◽  
Structure Activity ◽  
Large Numbers ◽  
The Relationship

Investigation of the relationship between the antibacterial activity of penicillins and the chemical nature of the side chain began in earnest in 1957, when the isolation of 6-aminopenicillanic acid (6-APA) made possible the preparation of large numbers of N -substituted derivatives. Since that time some 1800 different penicillins have been prepared and studied in Beecham Research Laboratories, and the number examined throughout the world must amount to several thousands. The purpose of the present survey is to try to summarize the general patterns of structure-activity relationships which have emerged from these studies. 6-APA itself has only a low order of antibacterial activity, and the same applies to derivatives in which the amino group at position 6 is substituted by radicals other than acyl groups (figure 1). Hence it soon became clear that no advantage was to be gained from such considerable structural variations, and efforts were concentrated on preparing true penicillins containing acyl side-chains. Virtually all of these show considerable activity in vitro against at least some bacteria, but the spectrum of activity varies widely.

scholarly journals In vitro antioxidant and antimicrobial activity of carotenoid pigment extracted from Sporobolomyces sp. isolated from natural source

2014 ◽  
Vol 6 (2) ◽  
pp. 649-653 ◽  
Author(s):  
M. R. A. Manimala ◽  
R. Murugesan
Keyword(s):  
Antibacterial Activity ◽  
Antioxidant Activities ◽  
Steady Increase ◽  
Carotenoid Pigment ◽  
E Coli ◽  
Chelating Activity ◽  
Metal Chelating ◽  
Potential Source ◽  
Antioxidant And Antimicrobial Activity

The aim of the present study was to isolate and study about the antioxidant and antibacterial activity of carotenoid pigment. Sporobolomyces sp. isolated from the phyllosphere surface of rice plant has found to produce carotenoid pigment. The present investigation was carried out for antioxidant assays viz., DPPH, iron reducing and metal chelating activity. A steady increase in the antioxidant activities was observed in the carotenoid pigment with raising the pigment concentration. In the present study, the maximum antioxidation characteristics of carotenoid by DPPH, iron reducing and metal chelating assays (75.04 %, 1.88 % and 59.32 %) were achieved by pigmentation of Sporobolomyces sp. at the concentration of 100 μg ml-1. The antibacterial activity was studied on several organisms like Enterococcus sp., Staphylococcus aureus, Streptococcus faecalis, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa. Among the six pathogens, the pigment was found to be more effective against E. coli (2.9 cm) and S. aureus (2.6 cm). This study revealed that yeast carotenoid pigment was a potential source for its use in food and pharmaceutical applications.

Amoxycillin - a new antibiotic

1972 ◽  
Vol 10 (16) ◽  
pp. 61-62
Keyword(s):  
Antibacterial Activity ◽  
Hydroxyl Group ◽  
Cross Resistance ◽  
Side Chain

Amoxycillin (Amoxil) is a new penicillin which differs from ampicillin only in possessing a hydroxyl group on the side chain. In vitro the drugs have identical antibacterial activity and cross-resistance is complete.1 Nevertheless the manufacturers make only a cursory comparison between features of the two antibiotics in their promotional literature. This is a serious omission, since a new antibiotic should not be launched with so little reference to the yard-stick by which it will inevitably be assessed, namely the manner in which it compares with the well-tried ampicillin, over which it may have certain advantages. Bencard, which markets Amoxil is in fact a subsidiary of Beecham, the makers of ampicillin.

scholarly journals Improvement of antibacterial efficacy using antibiotic encapsulated silica-containing redox nanoparticles

2021 ◽  
Vol 24 (1) ◽  
pp. 1854-1861
Author(s):  
Han Ngoc Tran ◽  
Nhu-Thuy Trinh ◽  
Hoai-Ngan Thien Pham ◽  
Hanh Thi Ngoc Nguyen ◽  
Vong Binh Long
Keyword(s):  
Antibacterial Activity ◽  
Nitroxide Radical ◽  
Antibacterial Activities ◽  
Diffusion Method ◽  
Side Chain ◽  
Oxygen Species ◽  
E Coli ◽  
Redox Nanoparticle ◽  
Average Size

Purpose: Improving solubility and antibacterial efficiency of cephalothin by using silica-containing redox nanoparticle (siRNP) as a system to encapsulate and deliver this hydrophobic antibiotic. Methods: siRNP was synthesized by assembling amphiphilic block copolymers possessing a reactive oxygen species scavenging nitroxide radical and drug absorptive silica moieties in a hydrophobic side chain. Cephalothin, a hydrophobic antibiotic, was encapsulated into siRNP (cephalothin@siRNP) by mixing and dialysis methods. Antibacterial activity of cephalothin@siRNP against Staphylococcus aureus (S. aureus) và Escherichia coli (E. coli) was evaluated by the agar diffusion method. Results: The average size of siRNP and cephalothin@siRNP was 43.83 nm and 50.15 nm, respectively. After encapsulation in siRNP, the solubility of cephalothin was improved compared to cephalothin in an aqueous solution. The result showed that in vitro antibacterial activities of cephalothin and cephalothin@siRNP had no statistical difference after 24 h incubation on agar plates on both S. aureus and E. coli. However, after an extended incubation time, regrowth of E. coli colonies in the inhibitory zone was found in cephalothin treated plate. Interestingly, E. coli regrowth was significantly reduced in plates treated with cephalothin@siRNP. Conclusion: In this study, siRNP successfully encapsulated cephalothin and enhanced the solubility of this drug. The antibacterial activity of cephalothin is prolonged when encapsulated in siRNP, which suppressed the reccurrence of E. coli colonies. Cephalothin@siRNP has the potential to inhibit antibiotic resistance.

SENSITIVITY OF THE RAT DIAPHRAGM TO GROWTH HORMONE.

1967 ◽  
Vol 54 (4) ◽  
pp. 645-662 ◽  
Author(s):  
Å. Hjalmarson ◽  
K. Ahrén
Keyword(s):  
Growth Hormone ◽  
Inhibitory Effect ◽  
Rat Diaphragm ◽  
Intracellular Accumulation ◽  
Slight Effect ◽  
Kidney Capsule ◽  
Muscle Tissues ◽  
Hypophysectomized Rats ◽  
Isolated Rat

ABSTRACT The effect of growth hormone (GH) in vitro on the rate of intracellular accumulation of the non-utilizable amino acid α-aminoisobutyric acid (AIB) was studied in the intact rat diaphragm preparation. Bovine or ovine GH (25 μg/ml incubation medium) markedly stimulated the accumulation of AIB-14C by diaphragms from hypophysectomized rats, while there was no or only a very slight effect on diaphragms from normal rats. In diaphragms from rats with the pituitary gland autotransplanted to the kidney capsule GH in vitro stimulated the accumulation of AIB-14C significantly more than in diaphragms from normal rats but significantly less than in diaphragms from hypophysectomized rats. Injections of GH intramuscularly for 4 days to hypophysectomized rats made the diaphragms from these rats less sensitive or completely insensitive to GH in vitro. These results indicate strongly that the relative insensitivity to GH in vitro of diaphragms from normal rats is due to the fact that the muscle tissues from these rats has been exposed to the endogenously secreted GH. The results show that GH can influence the accumulation of AIB-14C in the isolated rat diaphragm in two different ways giving an acute or »stimulatory« effect and a late or »inhibitory« effect, and that it seems to be a time-relationship between these two effects of the hormone.

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