Structural studies on pyrrolomycins C, D and E.

Pyrrolomycins C, D and E are new members of the pyrrolomycin group of antibiotics produced by an Actinosporangium sp. The structures of pyrrolomycins C and D were determined to be 2,3-dichloro-5-(3',5'-dichloro-2'-hydroxybenzoyl)pyrrole and 2,3,4-trichloro-5-(3',5'-dichloro-2'-hydroxybenzoyl)pyrrole, respectively, by means of spectroscopic and synthetic approaches while that of pyrrolomycin E was shown to be 5-chloro-2-(3',5'-dichloro-2'-hydroxyphenyl)-3-nitropyrrole by spectroscopic data.

BN-183B, a new antitumor antibiotic produced by Pseudomonas. Taxonomy, isolation, physico-chemical and biological properties.

BN-183B is a new antitumor antibiotic with chlorine in its molecule found in the culture broth of Pseudomonas sp. BN-183. The compound was weakly basic and isolated as a hydrochloride in a pure state. The molecular formula of its free base was determined as C14H20N2O6Cl2. The antibiotic showed not only strong antimicrobial activity against both Gram-positive and Gram-negative bacteria but also marked activity toward experimental tumors such as lymphoid leukemia L-1210 and lymphocytic leukemia P-388 in mice. No mutagenicity of BN-183B was noted.

Bioconversion of ribostamycin (SF-733). II. Isolation and structure of 3-N-acetylribostamycin, a microbiologically inactive product of ribostamycin produced by Streptomyces ribosidificus.

The isolation and structure determination of 3-N-acetylribostamycin, a microbiologically inactive derivative, produced enzymatically from ribostamycin by Streptomyces ribosidificus is described. The location of the acetyl group was established by mass and NMR spectrometry of the new compound and its derivatives, and by optical rotation studies conducted on N-ethoxycarbonyl-2-deoxystreptamine. The latter compound was obtained by partial acid hydrolysis of tri-N-ethoxycarbonyl-N-acetylribostamycin.

Pyrrolomycins C, D and E, new members of pyrrolomycins.

Pyrrolomycins C, D and E, new members of pyrrolomycins produced by Actinosporangium vitaminophilum SF-2080, have been isolated by chromatography on a basic alumina column. Three antibiotics have chlorinated pyrrole nuclei linked directly or via carbonyl function to the dichlorophenol moiety. Pyrrolomycins C and E are active against Gram-positive bacteria, while the spectrum of pyrrolomycin D is broad including Gram-positive, Gram-negative bacteria and fungi.

Studies on antibiotics BN-227 and BN-227-F, new antibiotics. II. Chemical structure of antibiotics BN-227 and BN-227-F.

The structure of a new antibiotic BN-227 was determined as I by physico-chemical methods. The X-ray analysis also suggested the structure of I. The structure of antibiotic BN-227-F was determined as II. The antibiotic BN-227-F was prepared by addition of a solution of ferric chloride to antibiotic BN-227.

Studies on antibiotics BN-227 and BN-227-F, new antibiotics. I. Taxonomy, isolation and characterization.

The two new antibiotics, BN-227 and BN-227-F, were isolated from the fermentation broth of Pseudomonas sp. BN-227. BN-227 has a molecular formula C7H9NO3, and melts at 115 degrees C. BN-227-F has a molecular formula C21H24N3O9Fe, and melts at 156 degrees C. BN-227-F is a chelate compound consisting of three similar ligands (antibiotic BN-227) and ferric ion. The two antibiotics have antimicrobial activity against Gram-positive and Gram-negative bacteria.

Pyrrolomycins F1, F2a, F2b and F3, new metabolites produced by the addition of bromide to the fermentation.

New antibiotics, pyrrolomycins F1, F2a, F2b and F3 were produced by Actinosporangium vitaminophilum sp. nov. when bromide ion was added to the fermentation medium. Addition of other halide ions such as chloride, iodide and fluoride ion showed no effect on pyrrolomycin production, affording polychlorinated pyrrolomycins A, B, C, D and E, but no F components. All four new antibiotics contain 2 approximately 4 mol of bromine, and their substitutional position was determined by X-ray analysis and synthesis, supported by spectroscopic analysis. They are strongly active against Gram-positive bacteria and fungi.

Studies on a new aminoglycoside antibiotic, dactimicin. II. Isolation, structure and chemical degradation.

A new aminoglycoside antibiotic, dactimicin produced by a Dactylosporangium matsuzakiense SF-2052 has been isolated by column chromatography on a cation-exchange resin and CM-sephadex. The structure of dactimicin was determined to be 4-amino-1,4-dideoxy-3-O-(2,6-diamino-2,3,4,6,7-pentadeoxy-beta-L-lyxo- heptopyranosyl)-1-[(N-formimidoylglycyl)-methylamino]-6-O-methyl-L-chiro-inosit ol. Alkaline hydrolysis of dactimicin afforded 1-N-(N-formylglycyl)fortimicin B, fortimicin B, fortimicin A and an acyl migration product, 2'-N-(N-formylglycyl)fortimicin B.