2-Hydroxy muconate

Exceptions exist to this tendency for ready incorporation of the initial transformation products of xenobiotic compounds into a common pathway. First, occasionally a product is formed which is unreactive in subsequent steps in a particular microorganism. Such partially degraded compounds have been referred to as dead-end metabolites (Knackmuss, 1981). An example of this is the 5-chloro-2-hydroxy-muconic acid semialdehyde produced by the meta cleavage of 4-chlorocatechol by a particular pseudomonad species ... 

Iron Content and Interaction with Substrate. Metapyrocatechase. Crystalline metapyrocatechase was obtained from a strain of Pseudomonas arvilla by the method previously described (iO). The enzyme catalyzes the conversion of catechol by extradiol cleavage to -hydroxy-muconic c-semialdehyde with the insertion of two atoms of molecular oxygen (Reaction 1). 

The enzyme catalyzes the intradiol cleavage of catechol with the insertion of 2 atoms of molecular oxygen to form e/s.c/s-muconic acid. The enzyme also catalyzes the oxidation of various catechol derivatives, including 4-methylcatechol, 4-chloro-catechol, 4-formylcatechol (protocatechualdehyde), 4,5-dichlorocatechol, 3,5-di-chlorocatechol, 3-methylcatechol, 3-methoxycatechol, and 3-hydroxycatechol (pyro-gallol). All of these substrates give products having an absorption maximum at around 260 nm characteristic of t7s-c/s-muconic acid derivatives. However, when 3-methylcatechol is used as a substrate, the product formed shows an absorption maximum at 390 nm besides that at 260 nm. These two absorption maxima are found to be attributable to two different products, 2-hydroxy-6-oxo-2,4-heptadienoic acid (7), and 5-carboxy-2-methyl-2,4-pentadienoicacid(2-methylmuconic acid), (2) [Eq. (19)]96. ... 

Figure 1. Catabolic pathways for degradation of naphthalene by bacteria. I, naphthalene II, cis-l,2-dihydro-l,2-dihydroxynaphthalene (naphthalene dihydrodiol) III, l,2-dihydrox3maphthalene IV, 2-hydroxy-chromene-2-carboxylate V, mns-o-hydroxybenzyIidene pyruvate VI, salicylaldehyde Vn, salicylate VIII catechol IX, c 5,ci8-muconate semialdehyde X, cis,ci8-muconate XI, gentisate XII, maleylpyruvate.

Pyrocatechol ozonation at 15% conversion degree gave the following yields o-quinone - 85%, pyrogallol - 3%, ozonide - 10%, muconic acid -2%, maleic acid and fumaric acids and the polymeric products - 1%. The ratio between the amount of absorbed ozone and the consumed pyrocatechol was calculated to be 6. Similar ratio values have also been obtained for the other hydroxybenzenes with free hydroxy groups. 

CyHyBrO, 3-Bromo-4,4-dihydroxypimelic acid dilactone, 35B, 5 C7H8O3, 5-Hydroxy-trans-2,trans-4-pentadienal acetate, 43B, 9 CyHeO, Monomethyl-trans,trans-muconate, 32B, 15 CyHeO, -Methylmuconic acid 7-lactone, 23, 542 C7H11NO, N-Methylsorbamide, 44B, 8... 

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