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Biomedical subjects

A W Goldstein

Publications and source records attributed to A W Goldstein.

12 recordsLinked to original sources
PubMed1980

4-N-acylfortimicins B and the preparation of fortimicin A from fortimicin B.

Selective 4-N-acylation of fortimicin B (2) has been accomplished by 4-N-acylation of 1,2',6'-tri-N-benzyloxycarbonylfortimicin B (4) followed by hydrogenolysis of the N-protecting benzyloxycarbonyl groups. In this manner, fortimicin B was converted into fortimicin A (1), and a series of 4-N-acylfortimicins B (3) was prepared for antibacterial assay. The key intermediate, 1,2',6'-tri-N-benzyloxycarbonylfortimicin B, was prepared either directly from fortimicin B or by converting fortimicin A into 1,2',6',2''-tetra-N-benzyloxycarbonylfortimicin A (6a), followed by selective hydrolysis of the 4-N-(N-benzyloxycarbonyl)glycyl group of the latter.

Acylation↗
PubMed1980

synthesis of 2-deoxyfortimicins and 1-deamino-2-deoxy-2-epi-aminofortimicins via 2-O-methanesulfonylfortimicin B.

The synthesis of 2-deoxyfortimicins A (15) and B (11) and 1-deamino-2-deoxy-2-epi-amino-fortimicins A (18) and B (12) is described. Two routes have been developed for synthesis of the key intermediate 2-O-methanesulfonylfortimicin B (7). One route involves selective blocking of fortimicin B with B-benzyloxycarbonyl groups followed by formation of a 4,5-salicylaldehyde oxazolidine derivative. Subsequent mesylation followed by deblocking gave 7. A more efficient route to 7 involves concomitant salicylaldehyde Schiff base and 4,5-oxazolidine formation followed by mesylation and hydrolysis. The formation of 1,2(R)-epiminofortimicin B (8) from 7 followed by RANEY nickel reduction gave 2-deoxyfortimicin B and 1-deamino-2-deoxy-2-epi-aminofortimicin B, which were converted to the corresponding fortimicin A derivative by selective N-blocking, N-acylation and subsequent deblocking. The antibacterial activities of the new fortimicin A derivatives are presented.

Aminoglycosides↗
PubMed1979

4-N-Aminoacylfortimicins E.

The conversion of fortimicin E, a minor metabolite from the Micromonospora olivoasterospora fermentation which also produces fortimicin A and fortimicin B, to four 4-N-aminoacylfortimicins E was accomplished. The new 4-N-aminoacylfortimicins E showed only weak antimicrobial activity against several Gram-negative and Gram-positive microorganisms.

Aminoglycosides↗
PubMed1978

The structures of the m-chloroperbenzoic acid oxidation products of 8,9-anhydroerythromycins A- and B-6,9-hemiacetal and of (8S)-8-hydroxyerythromycin B.

13C-NMR studies have confirmed the structures of (8S)-8-hydroxyerythromycins A- and B-6,9;9,11-acetal proposed by KROWICKI and ZAMOJSKI2,3) for the products of the m-chloroperbenzoic acid oxidation of 8,9-anhydroerythromycins A- and B-6,9-hemiacetal. The preparations of (8S)-8-methylthiomethoxy- and (8S)-8-methoxyerythromycin B-6,9;9,11-acetals are described. The latter are stable in aqueous acetic acid under conditions which convert (8S)-8-hydroxyerythromycin B-6,9;9,11-acetal into (8S)-8-hydroxyerythromycin B.

Acetates↗
PubMed1978

Biotransformation of lankamycin, darcanolide, and 11-acetyllankolide by a blocked mutant of the erythromcyin producing organism Streptomyces erythreus.

The biotransformation of lankamycin and congeners darcanolide and 11-acetylankolide by a blocked mutant of the erythromycin-producing organism Streptomyces erythreus, which cannot synthesize erythromycin without supplementation with erythromycin precursors, was investigated. Darcanolide and 11-acetyllankolide were converted into the corresponding 15-deoxy-15-oxo derivatives. Lankamycin was transformed to 15-deoxy-15-oxolankamycin, 4''-deacetyl-15-deoxy-15-oxolankamycin and 3'-de-O-methylankamycin. None of the derivatives possessed high antimicrobial activity.

Anti-Bacterial Agents↗
PubMed1977

Fortimicins A and B, new aminoglycoside antibiotics. III. Structural identification.

The structures of fortimicins A and B have been determined by PMR, CMR, mass spectra and CD combined with chemical degradations. Both antibiotics are pseudodisaccharides and incorporate a novel aminocyclitol, fortamine. In contrast to the diaminocyclitol moieties of known aminoglycosides, fortamine is a 1,4-diamine, contains both N- and O-methyl groups and possesses chiro stereochemistry. Both antibiotics are glycosides of 6-epi-purpurosamine B, but fortimicin A differs from fortimicin B by being a glycyl amide.

Aminoglycosides↗