| catechol | A term loosely used for catechin, which contains a pyrocatechol moiety, and as the root of catecholamines, which are pyrocatechol derivatives. Synonym: pyrocatechol. (05 Mar 2000) |
|---|---|
| catechol 1,2-dioxygenase | <enzyme> Little activity towards chlorinated substrates Registry number: EC 1.13.11.1 Synonym: pyrocatechase, catechol-1,2-oxygenase, pyrocatechol 1,2-dioxygenase (26 Jun 1999) |
| catechol 2,3-dioxygenase | <enzyme> An oxidoreductase oxidizing catechol, with oxygen, to 2-hydroxymuconate saemialdehyde. Synonym: metapyrocatechase. (05 Mar 2000) |
| catechol o-methyltransferase | <enzyme> An enzyme of the transferase class that catalyses the transfer of a methyl group from s-adenosylmethionine to a catechol or catecholamine such as dopa, dopamine, norepinephrine, or epinephrine. (converting to normetanephrine and metanephrine, respectively), the methyl group coming from S-adenosyl-l-methionine. An important step in the catabolism of the catecholamines. The enzyme occurs in the cytoplasm, particularly in the kidney, liver, and central nervous system. Chemical name: S-Adenosyl-L-methionine:catechol O-methyltransferase Registry number: EC 2.1.1.6 (05 May 2002) |
| catechol oestrogen | Any 2-hydroxylated derivative of an oestrogen; they, with their methylated derivatives, can account for up to one-half of all excreted oestrogen metabolites. (05 Mar 2000) |
| catechol oxidase | <enzyme> An enzyme of the oxidoreductase class that catalyses the reaction between catechol and oxygen to yield benzoquinone and water. It is a complex of copper-containing proteins that acts also on a variety of substituted catechols. Chemical name: 1,2-Benzenediol:oxygen oxidoreductase Registry number: EC 1.10.3.1 (12 Dec 1998) |
| catecholamine | <biochemistry, investigation, physiology> A type of biogenic amine derived from tyramine, characterised as alkylamino derivatives of ortho-dihydroxyphenylalkylamines in turn derived from tyrosine. Catecholamines include adrenaline, noradrenaline and dopamine, with roles as hormones and neurotransmitters. Measurement of noradrenaline and adrenaline can be made in blood and urine. Elevations may be seen in pheochromocytoma or neuroblastoma. Normal blood levels of adrenaline should be: 20 ng/ml and normal blood levels of noradrenaline should be 60 ng/ml. (16 Mar 1998) |
| catechols | A group of 1,2-benzenediols that contain the general formula r-c6h5o2. (12 Dec 1998) |
| oestrogens, catechol | 2- or 4-hydroxyoestrogens. Substances that are physiologically active in mammals, especially in the control of gonadotropin secretion. Physiological activity can be ascribed to either an oestrogenic action or interaction with the catecholaminergic system. (12 Dec 1998) |
|---|