scholarly journals Chemical structure and biodegradability of halogenated aromatic compounds. Conversion of chlorinated muconic acids into maleoylacetic acid

1980 ◽  
Vol 192 (1) ◽  
pp. 339-347 ◽  
Author(s):  
E Schmidt ◽  
H J Knackmuss
Keyword(s):  
Aromatic Compounds ◽  
Chemical Structure ◽  
Pseudomonas Sp ◽  
Muconic Acid ◽  
Low Activity ◽  
Muconate Cycloisomerase ◽  
Halogenated Aromatic Compounds

1. An enzyme for the cycloisomerization of 2- and 3-chloro-cis, cis-muconic acid was isolated from 3-chlorobenzoate-grown cells of Pseudomonas sp. B13. It was named muconate cycloisomerase II, because it could it clearly be differentiated by its Km and Vmax. values from an ordinary muconate cycloisomerase, which functioned in benzoate catabolism and exhibited low activity with the chlorinated substrates. 2-Chloro-cis, cis-muconic acid was converted into trans- and 3-chloro-cis, cis–muconic acid into cis-4-carboxymethylenebut-2-en-4-olide together with dehalogenation. 2. An enzyme was isolated from chlorobenzoate-grown cells, which converted the 4-carboxymethylenebut-2-en-4-olides into maleoylacetic acid.

scholarly journals Chemical structure and biodegradability of halogenated aromatic compounds. Halogenated muconic acids as intermediates

1980 ◽  
Vol 192 (1) ◽  
pp. 331-337 ◽  
Author(s):  
E Schmidt ◽  
G Remberg ◽  
H J Knackmuss
Keyword(s):  
Chemical Structure ◽  
Acidic Solution ◽  
Pseudomonas Sp ◽  
Trans Form ◽  
Solution Ph ◽  
Muconic Acid ◽  
Acidic Solutions ◽  
Ph Conditions ◽  
Ylacetic Acid ◽  
Halogenated Aromatic Compounds

Substituted muconic acids were prepared from the corresponding catechols by pyrocatechase II from Pseudomonas sp. B13. The stabilities of substituted muconic acids were compared under different pH conditions. 3-Substituted cis, cis-muconic acids cycloisomerized readily in slightly acidic solutions, whereas 2-chloro- and 2-fluoro-cis, cis-muconic acids were stable under these conditions and could be isolated as crystalline compounds. They were isomerized to the cis, trans-form in highly acidic solution (pH 1), particularly when heated to 80 degrees C. Cycloisomerization of 2-chloro-cis, cis-muconic acid in 75% (v/v) H2SO4 yields 4-carboxymethyl-2-chloro-but-2-en-4-olide (4-chloro-2,5-dihydro-5-oxo-3H-furan-2-ylacetic acid). THe cis, cis-configuration of 2-chloromuconic acid was certified by 1H n.m.r. spectroscopy and by enzymic cycloisomerization. Although the cis, cis-configuration of 2-fluoromuconic acid was confirmed by corresponding spectroscopic data, it was not cycloisomerized by crude extracts or cycloisomerase II preparations from Pseudomonas sp. B13.

scholarly journals Chemical structure and biodegradability of halogenated aromatic compounds. Two catechol 1,2-dioxygenases from a 3-chlorobenzoate-grown pseudomonad

1978 ◽  
Vol 174 (1) ◽  
pp. 73-84 ◽  
Author(s):  
E Dorn ◽  
H J Knackmuss
Keyword(s):  
Heavy Metals ◽  
Aromatic Compounds ◽  
Chemical Structure ◽  
Specific Activity ◽  
Pseudomonas Sp ◽  
Ph Optimum ◽  
Molecular Weights ◽  
Halogenated Aromatic Compounds

1. Two catechol 1,2-dioxygenases, pyrocatechase I and pyrocatechase II, were found in 3-chlorobenzoate-grown cells of Pseudomonas sp. B 13. The latter enzyme showed high relative activities with 3- and 4-chlorocatechol compared with catechol. 2. In benzoate-grown cells, only pyrocatechase I was induced. It was purified 29-fold with a final specific activity of 20 mumol of catechol oxygenated/min per mg of protein and an overall yield of 22%. Because of the instability of pyrocatechase II on chromatography and dialysis, no increase of specific activity was obtained during the purification experiments. 3. Molecular weights of pyrocatechase I and pyrocatechase II were 82000 and 67000 respectively. 4. For both pyrocatechases the pH optimum was found to be at 8.0.5. Inhibitions of the two pyrocatechases by Cu2+ and Hg2+ ions and p-chloromercuribenzoate were different. The effect on pyrocatechase I after incubation for 20 h with the heavy metals was decreased by addition of 1 mM-2-mercaptoethanol to the reaction mixture. The inhibition of pyrocatechase II was even enhanced under these conditions. 6. Extradiol cleavage of 3-methylcatechol in addition to intradiol fission at a ratio of 1:14 was observed only with pyrocatechase I.

scholarly journals Chemical structure and biodegradability of halogenated aromatic compounds. Substituent effects on 1,2-dioxygenation of catechol

1978 ◽  
Vol 174 (1) ◽  
pp. 85-94 ◽  
Author(s):  
E Dorn ◽  
H J Knackmuss
Keyword(s):  
Chemical Structure ◽  
Substituent Effects ◽  
Alcaligenes Eutrophus ◽  
Reaction Rates ◽  
Pseudomonas Sp ◽  
Substituent Constant ◽  
Binding Studies ◽  
Km Value ◽  
Michaelis Constants ◽  
Halogenated Aromatic Compounds

1. The influence of halogen substituents on the 1,2-dioxygenation of catechols was investigated. The results obtained with the two isoenzymes pyrocatechase I and pyrocatechase II from the haloarene-utilizing Pseudomonas sp. B 13 and the pyrocatechase from benzoate-induced cells of Alcaligenes eutrophus B.9 were compared. 2. Substituents on catechol were found to interfere with O2 binding by the two isoenzymes from Pseudomonas sp. B 13, whereas the Km value for catechol kept constant at different O2 concentrations. 3. Electron-attracting substituents decreased the Km values for catechols. 4. Results from binding studies with substituted catechols demonstrated narrow stereospecificities of pyrocatechase I from pseudomonas sp. B 13 and the pyrocatechase from alcaligenes eutrophus B.9. In contrast, a low steric hindrance by substituents in the binding of catechols with pyrocatechase II was observed. 5. Low pK′1 values of substituted catechols resulted in low Michaelis constants. 6. Electron-attracting substituents such as halogen decreased the reaction rates of catechol 1,2-dioxygenation. The correlation of the Vmax. values observed with pyrocatechase II from Pseudomonas sp. B 13 with the substituent constant sigma+ (Okamoto–Brown equation) was distinctly greater than with Hammett's sigma values. The corresponding logVmax. against sigma+ correlation for pyrocatechase I was considerably disturbed by steric influences of the substituents.

scholarly journals Oxidation Reactions of Marchantin A Trimethyl Ether and Some Aromatic Compounds using m-Chloroperbenzoic Acid. Formation of Muconic Acid Ester and m-Chlorobenzoate

1999 ◽  
Vol 23 (8) ◽  
pp. 470-471
Author(s):  
Motoo Tori ◽  
Masakazu Sono ◽  
Keiko Takikawa ◽  
Reiko Matsuda ◽  
Masao Toyota ◽  
...  
Keyword(s):  
Aromatic Ring ◽  
Methyl Ether ◽  
Aromatic Compounds ◽  
Acid Ester ◽  
Acid Formation ◽  
Oxidation Reactions ◽  
Muconic Acid ◽  
Trimethyl Ether

On treatment with m-chloroperbenzoic acid, dihydroeugenol methyl ether and marchantin A trimethyl ether afford muconic acid ester derivatives by oxidation of the aromatic ring as well as hydroxylated derivatives; the m-chlorobenzoate of the dihydroeugenol derivative is also observed for the former.

Cytokinin activity of some substituted ureas and thioureas

1966 ◽  
Vol 165 (999) ◽  
pp. 245-265 ◽  
Keyword(s):  
Biological Activity ◽  
Active Compound ◽  
Phenyl Ring ◽  
Chemical Structure ◽  
Lower Activity ◽  
Cytokinin Activity ◽  
Hydrogen Atoms ◽  
Detectable Activity ◽  
Low Activity

N , N '-Diphenylurea was shown to have reproducible cytokinin activity . Some 500 ureas, mainly of the N -monosubstituted and N , N '-disubstituted types, were tested an d about one half of these were active. Attempts were made to correlate chemical structure with biological activity. Although there are some exceptions to nearly every generalization it has been possible to formulate some principles. (1) Phenyl urea was the simplest active compound. (2) An HNCONH bridge conferred higher activity than an HNCSNH linkage and any other tested arrangement of the bridge gave inactive com pounds. (3) Compounds in which both amino hydrogen atoms on one or both sides of the bridge were substituted were of low activity or were inactive. (4) Many com pounds of the type R NHCONH 2 in which R = a substituted phenyl ring were tested. Ring substitution generally increased the activity and the highest activity was associated with meta substitution and the lowest with ortho . Compounds with electron-attracting substituents were generally more active than those with electron-donating substituents. Pyridyl compounds were active but com pounds with non-planar rings were inactive. (5) In compounds of the type R NHCONH R ' in which R and R ' were phenyl or substituted phenyl groups the highest activities were usually found in com pounds with one unsubstituted phenyl ring. Those with two substituted phenyl groups generally had lower activity. Some ureas showed detectable activity at 0.1 parts/10 6 . This was about four times less active than kinetin when tested in the tobacco pith assay.

Screening of halogenated aromatic compounds in some raw material lots for an aluminium recycling plant

2004 ◽  
Vol 30 (3) ◽  
pp. 363-366 ◽  
Author(s):  
Seija Sinkkonen ◽  
Jaakko Paasivirta ◽  
Mirja Lahtiperä ◽  
Antero Vattulainen
Keyword(s):  
Aromatic Compounds ◽  
Raw Material ◽  
Aluminium Recycling ◽  
Halogenated Aromatic Compounds
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