Coumarins glucuronide

Acetonitrile, methanol and DMSO had no apparent effect on umbelliferone glucuronidation in human hepatocytes at concentration up to 2% [32]. With HLMs or expressed UGTs, inhibitory effects of organic solvents on glucuronidation of 7-hydroxy-4-trifluoromethyl-coumarin (7-HFC) and estradiol generally followed the order acetonitrile > ethanol > methonal > DMSO [33], DMSO did not inhibit estradiol-3-glucuronidation activity at a concentration up... 

Hardt, TJ. Ritschel, W.A. (1983) Dose-related pharmacokinetics of coumarin, 7-hydroxy-coumarin and 7-hydroxycoumarin glucuronide upon intraperitoneal administration of coumarin and 7-hydroxycoumarin in the rat. Arzneim.-Forsch., 33, 1442-1446 Haworth, S., Lawlor, T, Mortelmans, K., Speck, W. Zeiger, E. (1983) Salmonella mutagenicity test results for 250 chemicals. Environ. Mutagen., 5 (Suppl. 1), 3-142 Hazleton, L.W., Tusing, T.W., Zeitlin, B.R., Thiessen, R., Jr Murer, H.K. (1956) Toxicity of coumarin. J. Pharmacol, exp. Ther., 118, 348-358 Hoult, J. Payd, M. (1996) Pharmacological and biochemical actions of simple coumarins natural products with therapeutic potential. Gen. Pharmacol., 27, 713-722... 

Ritschel, W.A. Hardt, T.J. (1983) Pharmacokinetics of coumarin, 7-hydroxycoumarin and 7-hydroxycoumarin glucuronide in the blood and brain of gerbils following intraperitoneal administration of coumaxm. Arzneim.-Forsch., 33, 1254-1258 Ritschel, W.A. Hoffmann, K.A. (1981) Pilot study on bioavailability of coumarin and 7-hydroxycoumarin upon peroral administration of coumarin in a sustained-release dosage form. J. din. Pharmacol., 21, 294-300... 

Weber, U.S., Steffen, B. Siegers, C.-P. (1998) Antitumor-activities of coumarin, 7-hydroxy-coumarin and its glucuronide in several human tumor cell hues. Res. Comm. mol. Pathol. Pharmacol., 99, 193-206... 

Coumarins also have a C6-C3 skeleton, but they possess an oxygen heterocycle as part of the C3-unit. There are numerous coumarins, many of which play a role in disease and pest resistance, as well as UV-tolerance. The coumarin umbelliferone (1.21) is popular in enzyme assays. Umbelliferone esters can be used as a substrate for non-specific esterase enzyme assays and in fluorescent immunoassays (Jacks and Kircher, 1967). In order to quantify the enzyme activity of the popular reporter gene P-glucuronidase (GUS), plant extracts can be incubated with 4-methylumbelliferyl P-D-glucuronide (4-MUG 1.22), which upon hydrolysis... 

The commercially available fluorogenic substrate that has been described in detail in the literature for assay of beta-glucuronidase activity is 4-methyl umbelliferyl glucuronide (MUG). This compound is not fluorescent until cleaved by beta-glucuronide to release 4-methyl umbelliferone (7-hydroxy-4-methyl coumarin). The product is fluorescent only when the hydroxyl group is ionized. The pKa of this hydroxyl is around 8, and maximal fluorescence will only be obtained if the product is in solution at a pH greater than the pKa fluorescence is relatively low at the neutral pH of the living cell. 

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