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PubMedDate not supplied

Mutagenicity of naphthacene, a non-bay-region aromatic hydrocarbon, in Salmonella.

Naphthacene (2,3-benzanthracene, tetracene) was tested for mutagenicity towards Salmonella typhimurium strains TA1535, TA1537, TA1538, TA98 and TA100. Mutagenicity was seen in all strains except in TA1535 when liver S9 fraction from rats or mice was present. The increases in the number of revertants induced by naphthacene equalled those by other naturally occurring polycyclic aromatic hydrocarbons, benzo[a]pyrene and dibenz[ac]anthracene, in the strains TA98 and TA100.

Animals↗
PubMed1988

SF2446, new benzo[a]naphthacene quinone antibiotics. II. The structural elucidation.

Structures of new antibiotics SF2446A1, A2, A3, B1, B2 and B3 have been deduced by means of spectral analyses and chemical studies. The structure of SF2446A1 which is a main product of fermentation and has the strongest antimicrobial activity, has been proposed to be 11-(2,4-di-O-methyl-beta-L-rhamnopyranosyl)amino-5,6,6a,14a-tetrah ydro- 1,6,8,14a-tetrahydroxy-6a-methoxy-2-methoxycarbonyl-3-methyl- benzo[a]naphthacene-7,9,12,14-tetra-one. All of antibiotics have a novel benzo[a]naphthacene quinone skeleton and SF2446A1, A2, B1 and B2 have an N-glycosidic linkage with 2,4-di-O-methyl-L-rhamnose.

Aminoglycosides↗
PubMed1994

Bay- and fjord-region distortions in dibenz[a,j]anthracene and tetrabenzo[de,hi,mn,qr]naphthacene.

The crystal structure of 7,14-dimethyldibenz[a,j]anthracene (DMDBA) has been determined, and the crystal structure of tetrabenzo[de,hi,mn,qr]naphthacene (TBNC) has been redetermined at higher precision than previously reported. These molecules are polycyclic aromatic hydrocarbons (PAHs) that have, respectively, two hindered bay regions and two fjord regions; the former PAH is a known carcinogen. The extensive out-of-plane bending as a result of steric overcrowding in the bay and fjord regions in these PAHs is shown by these studies. For DMDBA, the angle between the 14-methyl group and the outer rings is 32.6 degrees. For TBNC, the angle between the outer rings of the molecule is 31.9 degrees. These structures are compared with those of related structures of 7,12-dimethylbenz[a]anthracene and dibenzo[g,p]chrysene. It appears that steric overcrowding in such PAHs can cause distortions of up to 33 degrees C. Such steric overcrowding will affect the conformations of bay- and fjord-region diolepoxides, which are the presumed activated metabolites in the carcinogenic process.

Benz(a)Anthracenes↗
PubMed1988

SF2446, new benzo[a]naphthacene quinone antibiotics. I. Taxonomy and fermentation of the producing strain, isolation and characterization of antibiotics.

New antibiotics SF2446A1, A2, A3, B1 and B2 have been isolated from the culture of Streptomyces sp. SF2446 and antibiotic SF2446B3 has been obtained by methanolysis of SF2446B1 or B2. SF2446A1, A2 and B1 showed strong inhibitory activities against mycoplasmas and Gram-positive bacteria. Empirical molecular formulae of antibiotics SF2446-A1, A2, A3, B1, B2 and B3 were determined to be C34H35NO15, C26H21NO11, C34H35NO14, C34H35NO14 and C26H21NO10, respectively.

Aminoglycosides↗
PubMed1988

The structures of new antifungal antibiotics, benanomicins A and B.

Structures of new antifungal antibiotics, benanomicins A and B were determined to be N-[[5-[6-deoxy-3-O-(beta-D-xylopyranosyl)-beta-D-galactopyranosyloxy+ ++ ]-5, 6-dihydro-1,6,9,14-tetrahydroxy-11-methoxy-3-methyl-8,13-dioxobenzo++ + [a]naphthacen-2-yl]carbonyl]-D-alanine and N-[[5-[4-amino-4,6-dideoxy-3-O-(beta-D-xylopyranosyl)-beta-D- galactopyranosyloxy]-5,6-dihydro-1,6,9,14-tetrahydroxy-11-methoxy- 3-methyl-8,13-dioxobenzo[a]naphthacen-2-yl]carbonyl]-D-al ani ne, respectively, by spectral analyses and chemical degradation studies.

Acetylation↗
PubMed1992

5838-DNI, a deoxyribonuclease inhibitor produced by Streptomyces sp. strain no. A-5838.

5838-DNI, an inhibitor of deoxyribonuclease (DNase) II from porcine spleen was produced by Streptomyces sp. strain No. A-5838. The structure of 5838-DNI was shown to be 1,4,4a,5,12,12a-hexahydro-4,4a,11,12a-tetrahydroxy-3,8-dimethoxy-9- methoxycarbonyl-10-methyl-1,5,12-trioxo naphthacene. Although similar in structure to tetracenomycin C, which is an antibiotic against Gram-positive bacteria, 5838-DNI has different antibacterial activity. 5838-DNI was distinguished from 5923-DNI, a previously reported DNase II inhibitor, in inhibitory activity against each enzyme. 5838-DNI showed dependency of inhibition on pH and temperature, and inhibited phosphodiesterase I in a competitive manner. These data suggest that 5838-DNI is the first reported example of an inhibitor of microbial origin which is able to inhibit DNase II and phosphodiesterase I.

Animals↗
PubMed1992

Benastatins A and B, new inhibitors of glutathione S-transferase, produced by Streptomyces sp. MI384-DF12. II. Structure determination of benastatins A and B.

Benastatins A and B, new inhibitors of glutathione S-transferase, have been isolated from the culture broth of Streptomyces sp. MI384-DF12. By X-ray crystallography, benastatin A was determined to be 8,13-dihydro-1,7,9,11-tetrahydroxy-13-dimethyl-8-oxo-3-pentyl- benzo[a]naphthacene-2-carboxylic acid. The structure of benastatin B was elucidated by NMR studies.

Benz(a)Anthracenes↗
PubMed1993

Bequinostatins A and B new inhibitors of glutathione S-transferase, produced by Streptomyces sp. MI384-DF12. Production, isolation, structure determination and biological activities.

New benzo[a]naphthacenequinone metabolites, designated bequinostatins A and B, have been isolated from the culture broth of the benastatin-producing strain Streptomyces sp. MI384-DF12. The structures of bequinostatins A and B were determined by spectral analyses to be 5,6,8,13-tetrahydro-1,6,7,9,11-pentahydroxy-8,13-dioxo-3- pentylbenzo[a]naphthacene-2-carboxylic acid and 2-decarboxybequinostatin A, respectively. Bequinostatin A showed considerable inhibitory activity against human pi class glutathione S-transferase (GST pi).

Animals↗
PubMed1994

Chemical structure- and time-dependent effects of polycyclic aromatic hydrocarbon-type inducers on rat liver cytochrome P450, DNA adducts, and I-compounds.

It is well documented that cytochrome P450IA1 (CYP1A1) plays an important role in carcinogen activation. CYP1A1/1A2 induction may serve as a biomarker of exposure to environmental toxins. In order to explore a specific role of CYP1A1 in metabolism of I-compounds (age-dependent indigenous DNA modifications), 2-month-old female Sprague-Dawley rats were treated ip with corn oil (2 ml/kg) or with one of several CYP1A1 inducers, i.e., dibenz[a,c]anthracene (DBA) (93 mumol/kg), benzo[a]pyrene (BP) (93 mumol/kg), naphthacene (NAP) (93 mumol/kg), or beta-naphthoflavone (BNF) (140 mumol/kg), once daily for 4 days. Levels of total cytochrome P450 and activities of CYP1A1-associated enzymes, i.e., ethoxycoumarin O-deethylase (ECD) and ethoxyresorufin O-deethylase (EROD), were determined in liver microsomes at 1, 8, or 15 days after the last treatment. DNA adducts and I-compounds were analyzed by nuclease P1-enhanced 32P-postlabeling. DNA synthesis rate was determined by measuring [3H]methylthymidine incorporation into DNA. Each inducer significantly elevated the total P450 level at 1 day. The enzyme levels in BP-, NAP-, and BNF-treated animals gradually returned to control by 8 and 15 days, but elevated levels persisted in DBA-treated rats. Similar trends were observed for ECD and EROD activities. DBA and BP, but not NAP and BNF, gave rise to several measurable DNA adducts, which persisted throughout the period of study. All P450 inducers, irrespective of adduct formation, strongly depleted both nonpolar and polar I-compounds, the effects being most pronounced at 1 and 8 days. These results imply a specific role for CYP1A1 in the regulation of I-compound metabolism, in addition to PAH activation.

Animals↗
PubMed1997

Direct mutagenicity of the polycylic aromatic hydrocarbon-containing fraction of smoked and charcoal-broiled foods treated with nitrite in acid solution.

The polycyclic aromatic hydrocarbons (PAH) containing fractions of smoked and charcoal-broiled foods, namely, Sheat fish (Kytopterus apogon), Mimrow (Crossocheilus reba), Freshwater catfish (Clarias batrachus), chicken wings, rice pork sausage and pork, in addition to naphthalene, acenaphthene, anthracene, phenanthrene, fluoranthene, pyrene, benz[a]anthracene, naphthacene, benzo[a]pyrene, benzo[e]pyrene, 9,10-dimethyl-1,2-benzanthracene, dibenz[ah]anthracene, benzo[ghi]perylene and coronene, were evaluated for their mutagenic potential using Salmonella typhimurium strains TA98 and TA100 in the absence of metabolic activation after being treated with nitrite (500 mM) for 4 hr at 37 degrees C and in acid solution pH 3.0-3.5. The presence of N-nitroso compounds was also determined. Results showed that nitrite could convert most samples to direct-acting mutagens towards both strains except for fluoranthene and benzo[ghi]perylene, which exhibit mutagenicity only with TA98. It was demonstrated that treatment of PAHs with nitrite in acid solution produced some non-N-nitroso direct-acting mutagens, suggesting that they might belong to nitro-PAHs. Therefore, the consumption of charcoal-broiled and smoked foods simultaneously with nitrite is not recommended.

Animals↗
PubMed1997

Correlation between the formation of cleavable complex with topoisomerase I and growth-inhibitory activity for saintopin-type antibiotics.

New saintopin-type antibiotics (e.g., saintopin, saintopin E, UCE1022, UCE6) with a naphthacene-dione structure have been discovered through our mechanistically oriented screening using purified mammalian DNA topoisomerases. Saintopin is a dual inducer of topoisomerase I- and topoisomerase II-mediated DNA cleavages in a cell-free system using purified enzymes, whereas others induced topoisomerase I- but not topoisomerase II-mediated DNA cleavage. The order of topoisomerase I-mediated DNA cleavage activity at lower concentrations (<1 microM) was UCE6 > saintopin > saintopin E > UCE1022. The DNA cleavage-intensity patterns induced by these antibiotics with topoisomerase I were identical, indicating that saintopin-type antibiotics have a similar DNA sequence selectivity in stabilization of the cleavable complex with topoisomerase I. Increases in protein/DNA complexes were observed in saintopin-type antibiotic-treated HeLa S3 cells using the potassium/sodium dodecyl sulfate precipitation method. Brief heating of these drugs-treated cells at 65 degrees for 10 min resulted in a rapid reduction in the number of protein/DNA complexes. Immunoblot analysis using antibody against human topoisomerase I or II revealed that the protein linked to DNA in saintopin-type antibiotic-treated cells is most likely topoisomerase I. These results suggest that saintopin-type antibiotics interfere with topoisomerase I in cells by trapping reversible topoisomerase I/DNA cleavable complexes. The formation of topoisomerase I/DNA complexes by saintopin-type antibiotics correlates well with their growth-inhibitory activities, suggesting that topoisomerase I can be the principal target of these antibiotics.

Animals↗
PubMed1996

Growth of rhodococcus S1 on anthracene.

Three slow-growing bacteria were isolated from a mixed culture enriched for growth on anthracene, using creosote-contaminated soil as the inoculum. Organisms were shown to use anthracene by the production of a clear zone around the colony after a mineral salts agar plate was sprayed with anthracene. All three bacteria were nonmotile, nonsporulating, gram-positive rods and stained acid-fast. Physiological and biochemical tests, GC content, and cell wall lipid patterns of whole cell methanolysates indicated that they belonged to the Nocardia-Mycobacterium-Rhodococcus group. On the basis of these characteristics and pyrolysis gas chromatography, they were assigned to the genus Rhodococcus. Growth of the isolates was slow on crystalline anthracene, giving a doubling time of 1.5-3 days, and they grew mainly on the crystal surface. When anthracene was supplied by precipitation from a solvent, doubling time was reduced to 1 day. All three isolates mineralized anthracene but not phenanthrene or naphthalene, nor could they grow on naphthalene, phenanthrene, fluorene, fluoranthene, acenaphthene, pyrene, chrysene, or naphthacene as sole carbon source. One isolate, Rhodococcus S1, was able to use 2-methylanthracene or 2-chloroanthracene as carbon source but not 1- or 9-substituted analogs. These results suggest that the initial enzyme attacking anthracene in these isolates has a narrow substrate specificity.

Anthracenes↗
PubMed1990

New antifungal antibiotics, pradimicins D and E. Glycine analogs of pradimicins A and C.

New antifungal antibiotics pradimicins D and E were isolated from the culture filtrates of Actinomadura hibisca P157-2 (ATCC 53557) and its mutant A2660 (ATCC 53762). The structure of pradimicin D is N-[[(5S,6S)-5-O-[4,6-dideoxy-4-(methylamino)-3-O-(beta-D- xylopyranosyl)-beta-D-galactopyranosyl]-5,6,8,13-tetrahydro-1,6,9,14- tetrahydroxy-11-methoxy-3-methyl-8,13-dioxobenzo[a]naphthacen++ +-2-yl] carbonyl]glycine, based on spectral analyses compared to pradimicin A. Pradimicin E is the des-N-methyl analog of pradimicin D. Pradimicins D and E were equal in activity to pradimicin A in vitro against a variety of fungi and in vivo against Candida albicans A9540 in mice.

Actinomycetales↗
PubMed1993

Pradimicins L and FL: new pradimicin congeners from Actinomadura verrucosospora subsp. neohibisca.

Pradimicin L, a new congener of pradimicin A having the D-glucosyl-D-thomosamine moiety at the C-5 position, was isolated from Actinomadura verrucosospora subsp. neohibisca subsp. nov. The structure of pradimicin L was deduced to be N-[[(5S,6S)-5-O-[4,6-dideoxy-4-(methylamino)-3-O-(beta-D-glucopyranosyl) - beta-D-galactopyranosyl]-5,6,8,13-tetrahydro-1,5,6,9,14-pentahydroxy-11- methoxy-3-methyl-8,13-dioxobenzo[a]naphthacene-2-yl]carbonyl ]-D-alanine by MS and NMR spectrometry and degradation studies. Pradimicin FL which has the D-serine moiety instead of D-alanine was produced by directed biosynthesis in D-serine-supplemented medium. Pradimicins L and FL have a broad spectrum of in vitro antifungal activity. Pradimicin L was equiactive to pradimicin A and pradimicin FL was more active than pradimicin L.

Actinomycetaceae↗