(n.) The concrete essence of the tonka bean, the fruit of Dipterix (formerly Coumarouna) odorata and consisting essentially of coumarin proper, which is a white crystalline substance, C9H6O2, of vanilla-like odor, regarded as an anhydride of coumaric acid, and used in flavoring. Coumarin in also made artificially.
Example Sentences:
(1) A phytochemical investigation of an ethanolic extract of the whole plant of Echites hirsuta (Apocynaceae) resulted in the isolation and identification of the flavonoids naringenin, aromadendrin (dihydrokaempferol), and kaempferol; the coumarin fraxetin; the triterpene ursolic acid; and the sterol glycoside sitosteryl glucoside.
(2) Among them, the coumarins, rutins, Centella asiatica extracts, procyanoside oligomers are the most prescribed.
(3) This novel coumarin derivative significantly inhibited skin tumor initiation by DMBA in SENCAR mice when given at a dose of 200 nmol, 5 min (69% inhibition) or 24 h (76% inhibition) prior to initiation.
(4) The aflatoxins are a family of complex coumarins produced by species of Aspergillus that are toxic and carcinogenic in animals.
(5) Coumarin and 7-HCG are best fitted to an open two-compartment model, whereas 7-HC is best fitted to an open one-compartment model.
(6) Drug interactions with coumarin anticoagulants and sulphonylurea compounds may produce bleeding episodes and hypoglycaemia, respectively.
(7) Neither macroscopic nor microscopic examination of liver tissue revealed any pathological alterations caused by coumarin.
(8) 10 coumarins used in perfumery, cosmetics and ointments, have been investigated by 2 different methods to determine their sensitizing capacity.
(9) Coumarin-induced hepatotoxicity was associated with significant increases in relative liver weight, plasma alanine and aspartate aminotransferase activities and hepatic non-protein sulphydryl groups.
(10) Treatment of isolated canine renal Na,K-ATPase with a stable diazomethane analog, 4-(diazomethyl)-7-(diethylamino)-coumarin (DEAC), results in enzyme inactivation.
(11) Among the non-infectious agents alcohol is the most important, followed by a combination of anticonvulsant drugs, valproic acid, retinoic acid, lithium, coumarin derivates, methyl mercury, aminopterin and methotrexate, cocaine and amniogenic bands.
(12) The results demonstrate a reserve capacity for the coumarin-sensitive reductase; at least 70% of the hepatic vitamin K1 2,3-epoxide reductase activity has to be eliminated before the vitamin K-dependent carboxylation of the clotting factors objectively becomes compromised.
(13) Coumarin and cimetidine appear to be safe and active agents in the treatment of metastatic renal carcinoma.
(14) This correlated well with the suppression by coumarin of the dextran-induced leucocyte response in vivo.
(15) In three patients painful reddening of a well-circumscribed area of the skin occurred within five days of starting anticoagulant treatment with phenprocoumon (Marcumar), and within a short time it developed into a full-blown picture of coumarin necrosis.
(16) A 2-7-fold increase in response to the inducers was seen in the amount of P-450Coh (cytochrome P-450 isoenzyme catalysing coumarin 7-hydroxylation) protein in Western immunoblots.
(17) These findings suggest that the coumarin ring system is largely responsible for the pharmacodynamic properties of warfarin, whereas the side-chain dictates the disposition and metabolism of the drug.
(18) The latter effect was effectively suppressed by a concomitant administration of a combination of troxerutin and coumarin (Venalot).
(19) A substantial improvement in the rate of detection of organic lesions affecting the olfactory pathway can be achieved by substituting odours such as musk ketone, exaltolide, linalyl acetate and coumarin for those in current use.
(20) Coumarin concentrations that inhibited growth of Pythium sp.
Umbelliferone
Definition:
(n.) A tasteless white crystalline substance, C9H6O3, found in the bark of a certain plant (Daphne Mezereum), and also obtained by the distillation of certain gums from the Umbelliferae, as galbanum, asafetida, etc. It is analogous to coumarin. Called also hydroxy-coumarin.
Example Sentences:
(1) Dimethylsulfoxide inhibits hydrolysis of the nucleotides and of the carboxylic phosphate substrates of the K-phosphatase reaction, but stimulates hydrolysis of the phenolic phosphate substrates (nitrophenylphosphate and umbelliferone phosphate) which normally are hydrolyzed more slowly than the other substrates.
(2) Focal brain pHi and focal cortical blood flow were measured by umbelliferone fluorescence.
(3) The phase reversal of the plasmalemma by umbelliferone is postulated to be through modified hormone receptor complex structure, which is yet to be substantiated.
(4) Using this concentration of umbelliferone, a histochemical study was done to estimate the sequential changes in tissue pH following cold-induced vasogenic brain edema in rats.
(5) A spectrophotofluorometric method is described for the quantitative analysis of coumarin, umbelliferone, and mixtures thereof in whole blood.
(6) Using real-time in vivo umbelliferone fluorescent imaging, cortical intracellular brain pH (pHi) and cortical blood flow (CBF) were measured in New Zealand white rabbits during generalized seizures induced by intravenous metrazole or sodium penicillin.
(7) A study was made in order to improve a new Salmonella identification test (Mucap Test) in which umbelliferone is released, giving a blue fluorescent light under a Wood lamp, after contact with Salmonella colonies.
(8) An alcoholic extract of the seeds of Coronilla varia L. showed inhibitory activity against KB cells in culture and was fractionated through a series of partitions, column chromatography, and preparative layer chromatography to yield hyrcanoside, daphnoretin, scopoletin, and umbelliferone.
(9) In the present study, umbelliferone was used for histochemically estimating the tissue pH in the rat brain.
(10) The clearance curves of umbelliferone, a lipid-soluble intracellular pH fluorescent indicator, from a visually avascular 80-micron field were used to cross-correlate rCBF with focal cortical perfusion.
(11) New methods are presented for the microdetermination of sulfotransferase and sulfatase activities in microdissected samples weighing 0.1 to 4 micrograms dry weight using umbelliferone and 4-methylumbelliferone sulfate as substrates.
(12) A fluorogenic drug reagent (FDR) (beta-galactosyl-umbelliferone-tobramycin) was prepared that is nonfluorescent under the conditions of the assay but is hydrolyzed upon catalysis by beta-galactosidase to yield a fluorescent product.
(13) Spectrophotometric and fluorimetric measurements of the systems A-D indicate that the tested hydroxycoumarins-coumarin, umbelliferone and 6-glucoside umbelliferone or esculin--undergo slow (systems A and B) and fast (systems C and D) consumption, leading to the degradation of coumarins.
(14) Umbelliferone, measuring a much smaller volume of tissue, showed a lower normocapnic flow and a more oblique PaCO2 response curve.
(15) Zn2+, Mn2+ and Pb2+ (as their chloride salts), N-acetylneuraminic acid, 4-methyl-umbelliferone and 2-acetoxybenzoic acid (acetylsalicylic acid) did not act as inhibitors.
(16) Following a 30-min microsomal incubation, 7-ethoxycoumarin, 4-methylumbelliferone (internal standard), and the metabolite umbelliferone were extracted with chloroform.
(17) A novel furanocoumarin, pterybinthinone, the known coumarins pteryxin and umbelliferone, and sucrose were isolated from this plant.
(18) A sensitive and specific fluorimetric method for the determination of 7-hydroxycoumarin (umbelliferone), and its application to liver homogenates and other tissue preparations, are described.
(19) Using protoplasts of guard cells of Vicia faba as model system, we document convincing first hand evidence a that lipid phase alterations could regulate ABA-induced closure of stomates and its reversal by umbelliferone.
(20) The parameters measured included intracellular brain pH and focal cortical blood flow (fCBF)--assessed by the umbelliferone technique--electrocorticograms, and cortical microcirculatory changes.