Ethylphenols

Chemically, wood tar is a complex mixture that contains at least 200 individual compounds, among which the foUowing have been isolated (1) 2-methoxyphenol, 2-methoxy-4-ethylphenol, 5-meth5i-2-methoxyphenol, 2,6-x5ienol, butyric acid, crotonic acid, 1-hydroxy-2-propanone, butyrolactone, 2-methyl-3-hydroxy-4JT-pyran-4-one, 2-methyl-2-propenal, methyl ethyl ketone, methyl isopropyl ketone, methyl furyl ketone, and 2-hydroxy-3-methyl-2-cyclopenten-l-one. 

Sudol uses fractions of coal tar rich in xylenols and ethylphenols. It is much more active and less corrosive than lysol, and remains more active in the presence of organic matter. The phenol coefficients of sudol against Mycobacterium tuberculosis, Staphylococcus aureus, and Pseudomonas aeruginosa are 6.3, 6, and 4, respectively. It also is slowly sporicidal (97). 

Another elastomer to find use is the substitution product of phenol and -ethylphenol along with an aHylic monomer to provide cross-link sites (5). This is trademarked EYPEL-A elastomer [66805-77-4] by Ethyl Corp., and designated PZ by ASTM. The substitution ratio is roughly 52 mol % phenol, 43% j )-ethylphenol, and 5% aHylic substituent. 

Inhibition of steroid sulphatase and sulphotransferase Steroid sulphotransferase catalyses the addition of sulphate to steroidal compounds whilst steroid sulphatase catalyses the reverse reaction. In vitro studies have demonstrated that a metabolite of genistein, 4-ethylphenol, can inhibit sulphotransferase (Harris et al, 2000). Sulphoconjugates of daidzein have also been found to potently inhibit these enzymes in vitro (Wong and... 

The oxidation by strains of Pseudomonas putida of the methyl group in arenes containing a hydroxyl group in the para position is, however, carried out by a different mechanism. The initial step is dehydrogenation to a quinone methide followed by hydration (hydroxylation) to the benzyl alcohol (Hopper 1976) (Figure 3.7). The reaction with 4-ethylphenol is partially stereospecific (Mclntire et al. 1984), and the enzymes that catalyze the first two steps are flavocytochromes (Mclntire et al. 1985). The role of formal hydroxylation in the degradation of azaarenes is discussed in the section on oxidoreductases (hydroxylases). 

Hopper DJ, L Cottrell (2003) Alkylphenol biotransformations catalyzed by 4-ethylphenol methylenehydroxy-lase. Appl Environ Microbiol 69 3650-3652. 

Mclntire W, DJ Hopper, JC Craig, ET Everhart, RV Webster, MJ Causer, TP Singer (1984) Stereochemistry of l-(4 -hydroxyphenyl)ethanol produced by hydroxylation of 4-ethylphenol by / -cresol methylhydroxy-lase. Biochem J 224 617-621. 

Darby JM, DG Taylor, DJ Hopper (1987) Hydroquinone as the ring-fission substrate in the catabolism of 4-ethylphenol and 4-hydroxyacetophenone by Pseudomonas putida Dl. J Gen Microbiol 133 2137-2146. 

The degradation of 4-ethylphenol and related componnds is initiated not by oxygenation bnt by dehydrogenation to a qninone methide followed by hydroxylation (Hopper and Cottrell 2003) (Figure 8.39), and the flavocy tochrome 4-ethylphenol methylene hydroxylase in Pseudomonas putida stain JDl has been characterized (Reeve et al. 1989). 

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