Microbial metabolism of fluoranthene: isolation and identification of ring fission products

1991 ◽  
Vol 34 (4) ◽  
Author(s):  
W.D. Weissenfels ◽  
M. Beyer ◽  
J. Klein ◽  
H.J. Rehm
Keyword(s):  
Fission Products ◽  
Microbial Metabolism ◽  
Isolation And Identification ◽  
Ring Fission

scholarly journals Degradation of Benzo[a]pyrene by Mycobacterium vanbaalenii PYR-1

2004 ◽  
Vol 70 (1) ◽  
pp. 340-345 ◽  
Author(s):  
Joanna D. Moody ◽  
James P. Freeman ◽  
Peter P. Fu ◽  
Carl E. Cerniglia
Keyword(s):  
High Performance ◽  
Culture Media ◽  
Optical Purity ◽  
Fission Products ◽  
Reversed Phase ◽  
Environmental Pollutant ◽  
Ring Fission ◽  
Uv Visible ◽  
Derivatives Of ◽  
Absolute Stereochemistry

ABSTRACT Metabolism of the environmental pollutant benzo[a]pyrene in the bacterium Mycobacterium vanbaalenii PYR-1 was examined. This organism initially oxidized benzo[a]pyrene with dioxygenases and monooxygenases at C-4,5, C-9,10, and C-11,12. The metabolites were separated by reversed-phase high-performance liquid chromatography (HPLC) and characterized by UV-visible, mass, nuclear magnetic resonance, and circular dichroism spectral analyses. The major intermediates of benzo[a]pyrene metabolism that had accumulated in the culture media after 96 h of incubation were cis-4,5-dihydro-4,5-dihydroxybenzo[a]pyrene (benzo[a]pyrene cis-4,5-dihydrodiol), cis-11,12-dihydro-11,12-dihydroxybenzo[a]pyrene (benzo[a]pyrene cis-11,12-dihydrodiol), trans-11,12-dihydro-11,12-dihydroxybenzo[a]pyrene (benzo[a]pyrene trans-11,12-dihydrodiol), 10-oxabenzo[def]chrysen-9-one, and hydroxymethoxy and dimethoxy derivatives of benzo[a]pyrene. The ortho-ring fission products 4-formylchrysene-5-carboxylic acid and 4,5-chrysene-dicarboxylic acid and a monocarboxylated chrysene product were formed when replacement culture experiments were conducted with benzo[a]pyrene cis-4,5-dihydrodiol. Chiral stationary-phase HPLC analysis of the dihydrodiols indicated that benzo[a]pyrene cis-4,5-dihydrodiol had 30% 4S,5R and 70% 4R,5S absolute stereochemistry. Benzo[a]pyrene cis-11,12-dihydrodiol adopted an 11S,12R conformation with 100% optical purity. The enantiomeric composition of benzo[a]pyrene trans-11,12-dihydrodiol was an equal mixture of 11S,12S and 11R,12R molecules. The results of this study, in conjunction with those of previously reported studies, extend the pathways proposed for the bacterial metabolism of benzo[a]pyrene. Our study also provides evidence of the stereo- and regioselectivity of the oxygenases that catalyze the metabolism of benzo[a]pyrene in M. vanbaalenii PYR-1.

scholarly journals Novel Ring Cleavage Products in the Biotransformation of Biphenyl by the Yeast Trichosporon mucoides

2001 ◽  
Vol 67 (9) ◽  
pp. 4158-4165 ◽  
Author(s):  
Rabea Sietmann ◽  
Elke Hammer ◽  
Michael Specht ◽  
Carl E. Cerniglia ◽  
Frieder Schauer
Keyword(s):  
Acetic Acid ◽  
Carboxylic Acid ◽  
High Performance ◽  
Fission Products ◽  
Transformation Product ◽  
Gas Chromatography Mass Spectrometry ◽  
Ring Cleavage ◽  
Aromatic Rings ◽  
Dead End ◽  
Ring Fission

ABSTRACT The yeast Trichosporon mucoides, grown on either glucose or phenol, was able to transform biphenyl into a variety of mono-, di-, and trihydroxylated derivatives hydroxylated on one or both aromatic rings. While some of these products accumulated in the supernatant as dead end products, the ortho-substituted dihydroxylated biphenyls were substrates for further oxidation and ring fission. These ring fission products were identified by high-performance liquid chromatography, gas chromatography-mass spectrometry, and nuclear magnetic resonance analyses as phenyl derivatives of hydroxymuconic acids and the corresponding pyrones. Seven novel products out of eight resulted from the oxidation and ring fission of 3,4-dihydroxybiphenyl. Using this compound as a substrate, 2-hydroxy-4-phenylmuconic acid, (5-oxo-3-phenyl-2,5-dihydrofuran-2-yl)acetic acid, and 3-phenyl-2-pyrone-6-carboxylic acid were identified. Ring cleavage of 3,4,4′-trihydroxybiphenyl resulted in the formation of [5-oxo-3-(4′-hydroxyphenyl)-2,5-dihydrofuran-2-yl]acetic acid, 4-(4′-hydroxyphenyl)-2-pyrone-6-carboxylic acid, and 3-(4′-hydroxyphenyl)-2-pyrone-6-carboxylic acid. 2,3,4-Trihydroxybiphenyl was oxidized to 2-hydroxy-5-phenylmuconic acid, and 4-phenyl-2-pyrone-6-carboxylic acid was the transformation product of 3,4,5-trihydroxybiphenyl. All these ring fission products were considerably less toxic than the hydroxylated derivatives.

scholarly journals The enzymic degradation of alkyl-substituted gentisates, maleates and malates

1971 ◽  
Vol 122 (1) ◽  
pp. 29-40 ◽  
Author(s):  
D. J. Hopper ◽  
P. J. Chapman ◽  
S. Dagley
Keyword(s):  
Dimethyl Ester ◽  
Fission Products ◽  
Gas Liquid Chromatography ◽  
Benzene Nucleus ◽  
Synthetic Compound ◽  
Intact Cells ◽  
General Sequence ◽  
Fluorescent Pseudomonas ◽  
Cell Extracts ◽  
Ring Fission

1. Cell-free extracts, prepared from a non-fluorescent Pseudomonas grown on m-cresol, oxidized gentisate and certain alkyl-substituted gentisates with the consumption of 1 mol of oxygen and the formation of 1 mol of pyruvate from 1 mol of substrate. 2. In addition to pyruvate, malate was formed from gentisate; citramalate was formed from 3-methylgentisate and 4-methylgentisate; 2,3-dimethylmalate was formed from 3,4-dimethylgentisate. 3. One enantiomer, d-(-)-citramalate, was formed enzymically from 3-methylgentisate, 4-methylgentisate and citraconate. l-(+)-Citramalate was formed from mesaconate by the same extracts. When examined as its dimethyl ester by gas–liquid chromatography, enzymically formed 2,3-dimethylmalate showed the same behaviour as one of the two racemates prepared from the synthetic compound. 4. Maleate, citraconate and 2,3-dimethylmaleate were rapidly hydrated by cell extracts, but ethylfumarate and 2,3-dimethylfumarate were not attacked. 5. Cell extracts oxidized 1,4-dihydroxy-2-naphthoate to give pyruvate and phthalate. 6. Alkylgentisates were oxidized by a gentisate oxygenase (EC 1.13.1.4) present in Pseudomonas 2,5. The ring-fission products were attacked by maleylpyruvase, but not by fumarylpyruvase, and their u.v.-absorption spectra were those expected for alkyl-substituted maleylpyruvates. 7. When supplemented with ATP, CoA, succinate and Mg2+ ions, an enzyme system from cells grown with 2,5-xylenol formed pyruvate from d- but not from l-citramalate. Extracts from cells grown with dl-citramalate or with itaconate attacked both d- and l-citramalate; other alkylmalates were cleaved in similar fashion to give pyruvate or 2-oxobutyrate. 8. These results accord with a general sequence of reactions in which the benzene nucleus of an alkylgentisate is cleaved to give an alkyl-substituted maleylpyruvate. The ring-fission products are hydrolysed to give pyruvate, plus alkylmalic acids which then undergo aldol fissions, probably as their CoA esters. In Pseudomonas 2,5 several homologous sequences of this general type appear to be catalysed by a single battery of enzymes with broad substrate specificities, whereas the metabolic capabilities of the fluorescent Pseudomonas 3,5 are more restricted. 9. Intact cells of both organisms metabolize d-malic acid by reactions that have not been elucidated, but are different from those which degrade alkylmalates.

scholarly journals Degradation of Phenanthrene and Anthracene by Cell Suspensions of Mycobacterium sp. Strain PYR-1

2001 ◽  
Vol 67 (4) ◽  
pp. 1476-1483 ◽  
Author(s):  
Joanna D. Moody ◽  
James P. Freeman ◽  
Daniel R. Doerge ◽  
Carl E. Cerniglia
Keyword(s):  
Culture Media ◽  
Fission Products ◽  
Alternative Pathways ◽  
Gram Positive Bacteria ◽  
Ring Fission ◽  
Diphenic Acid ◽  
Polycyclic Aromatic ◽  
Nuclear Magnetic Resonance Spectrometry ◽  
Magnetic Resonance Spectrometry ◽  
Uv Visible

ABSTRACT Cultures of Mycobacterium sp. strain PYR-1 were dosed with anthracene or phenanthrene and after 14 days of incubation had degraded 92 and 90% of the added anthracene and phenanthrene, respectively. The metabolites were extracted and identified by UV-visible light absorption, high-pressure liquid chromatography retention times, mass spectrometry, 1H and 13C nuclear magnetic resonance spectrometry, and comparison to authentic compounds and literature data. Neutral-pH ethyl acetate extracts from anthracene-incubated cells showed four metabolites, identified ascis-1,2-dihydroxy-1,2-dihydroanthracene, 6,7-benzocoumarin, 1-methoxy-2-hydroxyanthracene, and 9,10-anthraquinone. A novel anthracene ring fission product was isolated from acidified culture media and was identified as 3-(2-carboxyvinyl)naphthalene-2-carboxylic acid. 6,7-Benzocoumarin was also found in that extract. When Mycobacterium sp. strain PYR-1 was grown in the presence of phenanthrene, three neutral metabolites were identified as cis- andtrans-9,10-dihydroxy-9,10-dihydrophenanthrene andcis-3,4-dihydroxy-3,4-dihydrophenanthrene. Phenanthrene ring fission products, isolated from acid extracts, were identified as 2,2′-diphenic acid, 1-hydroxynaphthoic acid, and phthalic acid. The data point to the existence, next to already known routes for both gram-negative and gram-positive bacteria, of alternative pathways that might be due to the presence of different dioxygenases or to a relaxed specificity of the same dioxygenase for initial attack on polycyclic aromatic hydrocarbons.

scholarly journals Metabolism of myricetin and related compounds in the rat. Metabolite formation in vivo and by the intestinal microflora in vitro

1972 ◽  
Vol 130 (1) ◽  
pp. 141-151 ◽  
Author(s):  
L. A. Griffiths ◽  
G. E. Smith
Keyword(s):  
Oral Administration ◽  
Intestinal Microflora ◽  
Fission Products ◽  
Hydroxyl Groups ◽  
Dihydroxyphenylacetic Acid ◽  
Ring Fission ◽  
Hydroxyphenylacetic Acid ◽  
Micro Organisms

1. The metabolism of a group of polyphenols related in structure to myricetin (3,5,7,3′,4′,5′-hexahydroxyflavone), including myricetin, myricitrin, 3,4,5-trihydroxyphenylacetic acid, delphinidin, robinetin, tricetin, tricin, malvin and 5,7-dihydroxy-3′,4′,5′-trimethoxyflavone, has been studied both in vivo after oral administration to the rat and in vitro in cultures of micro-organisms derived from the intestine of the rat. 2. It was shown that the rat intestinal microflora are able to degrade compounds of this group to the ring-fission products observed in urine after oral administration of the specific flavonoid. 3. All flavones and flavonols possessing free 5- and 7-hydroxyl groups in the A ring and a free 4′-hydroxyl group in the B ring gave rise to ring-fission products that included 3′,5′-dihydroxyphenylacyl derivatives. 4. The metabolites 3,5-dihydroxyphenylacetic acid, 3-hydroxyphenylacetic acid, 3,5-dihydroxyphenylpropionic acid and 3-hydroxyphenylpropionic acid were isolated and identified by chromatographic and spectral methods. 5. On anaerobic incubation in a thioglycollate medium it was shown that intestinal micro-organisms can effect cleavage of glycosidic bonds, ring fission of certain flavonoid molecules showing 3′,4′,5′-trihydroxyphenyl substitution and dehydroxylation of certain flavonoid metabolites. 6. The urinary excretion of the metabolites 3,5-dihydroxyphenylacetic acid and 3-hydroxyphenylacetic acid was completely abolished when neomycin-treated rats were used.

scholarly journals Benz[a]anthracene Biotransformation and Production of Ring Fission Products by Sphingobium sp. Strain KK22

2013 ◽  
Vol 79 (14) ◽  
pp. 4410-4420 ◽  
Author(s):  
M. Kunihiro ◽  
Y. Ozeki ◽  
Y. Nogi ◽  
N. Hamamura ◽  
R. A. Kanaly
Keyword(s):  
Fission Products ◽  
Ring Fission

Nuclear Processes Related to the Ap Stars and the Heaviest Chemical Elements

1976 ◽  
Vol 32 ◽  
pp. 169-182
Author(s):  
B. Kuchowicz
Keyword(s):  
Nuclear Physics ◽  
Nuclear Reactions ◽  
Chemical Elements ◽  
Fission Products ◽  
Abundance Pattern ◽  
Isotopic Shifts ◽  
Processed Material ◽  
R Process ◽  
Ap Stars ◽  
Nuclear Processes

SummaryIsotopic shifts in the lines of the heavy elements in Ap stars, and the characteristic abundance pattern of these elements point to the fact that we are observing mainly the products of rapid neutron capture. The peculiar A stars may be treated as the show windows for the products of a recent r-process in their neighbourhood. This process can be located either in Supernovae exploding in a binary system in which the present Ap stars were secondaries, or in Supernovae exploding in young clusters. Secondary processes, e.g. spontaneous fission or nuclear reactions with highly abundant fission products, may occur further with the r-processed material in the surface of the Ap stars. The role of these stars to the theory of nucleosynthesis and to nuclear physics is emphasized.

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