Biomedical subjects

H Hanaki

Publications and source records attributed to H Hanaki.

41 records · Page 3Linked to original sources

PubMed1984

Phosalacine, a new herbicidal antibiotic containing phosphinothricin. Fermentation, isolation, biological activity and mechanism of action.

Phosalacine, a new herbicidal antibiotic containing phosphinothricin was isolated from the culture filtrate of a soil isolate Kitasatosporia phosalacinea KA-338. It was a water soluble, amphoteric compound obtained as an amorphous powder (C14H28N3O6P, MW 365). The antibiotic exhibited antimicrobial activity against Gram-positive and Gram-negative bacteria and some fungi on a minimal medium and the activity was reversed by L-glutamine. It also showed herbicidal activity against alfalfa. It is suggested that phosalacine was decomposed to provide phosphinothricin after its incorporation into microbial or plant cells, and exhibited the antimicrobial and herbicidal activities by inhibiting glutamine synthetase with phosphinothricin although phosalacine itself hardly inhibited the enzyme.

Actinomyces↗

PubMedDate not supplied

Improvement of water-soluble cephalosporin derivatives having antibacterial activity against methicillin-resistant Staphylococcus aureus.

We evaluated a series of novel cephem antibiotics, N-alkylpyridinium (alkyl group), N-carboxyethylpyridinium (carboxylic group), N-sulfoethylpyridinium (sulfonic group) and N-alkylquaternary ammonium salts (ammonioethyl group), N-alkyl-aromatic-quaternary ammonium salts and N-alkyl-heterocyclic quaternary ammonium salts (cyclic group) as vinylthio pyridinium derivatives at the C-3 position and hydroxyiminoaminothiazol at the C-7 position, for their activity against methicillin-resistant Staphylococcus aureus (MRSA) and their solubility, by measuring the minimum inhibitory concentrations (MICs) and the dissolving test in phosphate buffer. All tested compounds, except for the alkyl group, showed good solubility (>10%) in 1/15 M phosphate buffer (pH 7.2). The concentrations required to inhibit 80% of the bacterial strains (MIC80s) of the alkyl group, carboxylic group, sulfonic group, ammonioethyl group and cyclic group against MRSA were 1.56, 12.5-25, 6.25, 1.56 and 1.56 microg/ml, respectively. These results indicated that the ammonioethyl and cyclic groups yield the maximum anti-MRSA and anti-Enterococcus faecalis activity, and also good water solubility.

Cephalosporins↗

PubMedDate not supplied

In vitro antibacterial activity of TOC-50, a new parenteral cephalosporin against methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis.

The in vitro activity of TOC-50, a new parenteral cephalosporin, was assessed against methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus epidermidis (MRSE). TOC-50 showed excellent activity, which was stronger than that of methicillin, cloxacillin, the cephalosporins tested, imipenem, gentamycin, minocycline, ofloxacin and ciprofloxacin against MRSA and had a minimum inhibitory concentration (MIC) comparable to that of vancomycin (the MICs of TOC-50 and vancomycin for growth inhibition of 90% of the strains tested were 3.13 and 1.56 micrograms/ml, respectively). Against MRSE, TOC-50 exhibited excellent activity, which was stronger than that of methicillin, ampicillin, the cephalosporins tested and imipenem, and was twice as active as vancomycin. In terms of the bactericidal effect against MRSA, TOC-50 was superior to vancomycin.

Anti-Bacterial Agents↗

PubMedDate not supplied

In vitro and in vivo antibacterial activities of TOC-50, a new parenteral cephalosporin, against Enterococcus faecalis.

In vitro and in vivo antibacterial activities of TOC-50, a new parenteral cephalosporin, were assessed against Enterococcus faecalis. In vitro, TOC-50 had excellent activity, stronger than that of penicillin G, sulbactam/ampicillin, tazobactam/piperacillin, the cephalosporins tested, imipenem, vancomycin, gentamicin, tobramycin, arbekacin, amikacin, minocycline and ofloxacin against clinically isolated strains. In addition, TOC-50 was more active than penicillin G, sulbactam/ampicillin and imipenem against vancomycin-resistant E. faecalis NCTC 12201. In terms of bactericidal effect against the same strain, TOC-50 was superior to sulbactam/ampicillin and imipenem. In murine systemic infection models, TOC-50 had a potent protective activity against E. faecalis 42. Its protective activity was stronger than that of imipenem or vancomycin.

Animals↗

PubMedDate not supplied

Antibacterial activity of TOC-50, a new parenteral cephalosporin against penicillin-susceptible and penicillin-resistant Streptococcus pneumoniae.

TOC-50, a new parenteral cephalosporin, was assessed for antibacterial activity in vitro and in vivo. In vitro, the activity of TOC-50 was greater than ampicillin, erythromycin and gentamycin, and was equal to that of imipenem. The MICs of TOC-50 for 90% of the clinical isolates tested (MIC90 values) were 0.0125 microgram/ml for penicillin-susceptible Streptococcus pneumoniae, 0.2 microgram/ml for intermediately penicillin-resistant S. pneumoniae, and 0.39 microgram/ml for fully penicillin-resistant S. pneumoniae. In murine systemic-infection models, TOC-50 had a potent protective activity against penicillin-susceptible of fully penicillin-resistant S. pneumoniae. Its protective activity was stronger than that of imipenem.

Animals↗