| catechinic acid | <chemical> 3,3',4',5,7-flavanpentol. Extracted from uncaria gambier, acacia catechu and other plants; it stabilises collagen and is therefore used in tanning and dyeing; it prevents capillary fragility and abnormal permeability, but was formerly used as an antidiarrhoeal. Synonym: cachou; cashoo; cutch. Chemical name: 2H-1-Benzopyran-3,5,7-triol, 2-(3,4-dihydroxyphenyl)-3,4-dihydro-, (2R-trans)- (12 Dec 1998) |
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| 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) |
| catechu nigrum | Black catechu, an extract of the heart wood of Acacia catechu (family Leguminosae), used as an astringent in diarrhoea. Synonym: cutch. (05 Mar 2000) |
| catechuic acid | <chemical> 3,3',4',5,7-flavanpentol. Extracted from uncaria gambier, acacia catechu and other plants; it stabilises collagen and is therefore used in tanning and dyeing; it prevents capillary fragility and abnormal permeability, but was formerly used as an antidiarrhoeal. Synonym: cachou; cashoo; cutch. Chemical name: 2H-1-Benzopyran-3,5,7-triol, 2-(3,4-dihydroxyphenyl)-3,4-dihydro-, (2R-trans)- (12 Dec 1998) |
| categorical trait | <genetics> A feature that can conveniently and effectively be analyzed by sorting into classes either because there is no satisfactory way of measuring it (as with blood groups) or because it falls into natural classes so that the variation among classes far exceeds that within classes (e.g., the phenotypic effects of many enzyme polymorphisms); existence of categories suggests but does not prove the operation of a major, simple, underlying cause. Synonym: qualitative trait. (05 Mar 2000) |
| catelectrotonus | <physiology> The changes in excitability and conductivity in a nerve or muscle in the neighborhood of the cathode during the passage of a constant electric current. Origin: cathode + electrotonus (05 Mar 2000) |
| Catenabacterium | See entries under eubacterium lactobacillus. Origin: L. Catena, chain, + bacterium (05 Mar 2000) |
| catenabacterium contortum | <bacteria> A species found in cases of putrid, gangrenous appendicitis and in the intestines. (05 Mar 2000) |