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Biomedical subjects

R E Bambury

Publications and source records attributed to R E Bambury.

15 recordsLinked to original sources

Mesoionic pyridazine ribonucleosides. A novel biologically active nucleoside metabolite.

4-Cyano-3-oxido-1-beta-D-ribofuranosylpyridazinium (10a) has been prepared from 4-cyano-3(2H)-pyridazinone (4) by using a low-temperature, kinetically controlled, silyl Hilbert-Johnson reaction followed by deblocking of the resulting triacetate derivative, 8a, with NaHCO3 in methanol. 10a is apparently the first example of a mesoionic analogue of a pyrimidine nucleoside. It was discovered as a urine metabolite of 4-cyano-3(2H)-pyridazinone (4) in mice. 10a possesses Gram-negative antibacterial activity in vivo against a systemic Escherichia coli infection in mice with an ED50 of 25-50 mg/kg. A series of 4-substituted 3-oxidopyridazinium ribonucleosides, 11a-h, were synthesized as analogues of 10a. 4-Chloro-3-oxido-1-beta-D-ribofuranosylpyridazinium (11a) was found to be several times more active than 10a against E. coli in vitro although it showed no in vivo activity.

Animals↗

beta-lactam antibiotics derived from nitrogen heterocyclic acetic acids. 2. Cephalosporin derivatives.

Three cephalosporin derivatives were prepared from 1,4-dihydro-4-oxypyridine-1-acetic acid. These were the 7-aminocephalosporanic acid (7-ACA) derivative and the compounds with 5-methyl-1,3,4-thiadiazol-2-thiol and 1-methyl-1,2,3,4-tetrazole-5-thiol at C-3 of the cephalosporin nucleus. The antibacterial activity of the 7-ACA derivative was comparable to cephalothin, and that of the other two derivatives was comparable to cefazolin. The 7-ACA derivative, compared to cephalothin, was significantly less metabolized, was less protein bound, and had a longer half life.

Animals↗

Orally active cephalosporins and penicillins.

A number of orally active cephalosporins and penicillins with interesting biological activity were synthesized. Two of these, 7-[[[3,4-(methylenedioxy)phenyl]glycyl]amino]deacetoxycephalosporanic acid and 7-[[2-(2,3-dihydro-5-benzofuranyl)glycyl]amino]deacetoxycephalosporanic acid were considerably more active than cephalexin both in vitro and in vivo against staphylococcal and streptococcal infections.

Administration, Oral↗

Nitrones. 7. alpha-Quinoxalinyl-N-substituted nitrone 1,4-dioxides.

A series of alpha-quinoxalinyl-N-substitute nitrone 1,4-dioxides has been synthesize and evaluated as antibacterial and antiprotozoal agents. Structure-activity relationships are discussed. Of the compounds tested, alpha-(3-methyl-2-quinoxalinyl)-N-methylnitrone 1,4-dioxide (2) was the most active agent in vivo against the gram-negative and the gram-positive organisms.

Animals↗

Beta-lactam antibiotics with N-oxide side chains. 1. Quinoxaline N-oxides.

A series of penicillin derivatives of quinoxaline di-N-oxide carboxylic acids was prepared. These compounds were prepared from the acid chlorides and mixed anhydrides of the quinoxaline di-N-oxides. The compounds prepared exhibited minimal antibacterial activity against gram-negative organisms.

Animals↗

3-Substituted 2-formylquinoxaline 1,4-dioxides.

The methylnitrone of 3-methyl-1,4-dioxidoquinoxaline-2-carboxaldehyde (1) has been exceptional antibacterial activity in vivo. Derivatives of 3-hydroxymethyl-1,4-dioxidoquinoxaline-2-carboxaldehyde and 3-acetoxymethyl-1,4-dioxidoquinoxaline-2-carboxaldehyde were prepared. Several of these compounds were found to be antibacterial agents of the same order of activity as I.

Animals↗