- Novel resveratrol-based substrates for human hepatic, renal, and intestinal UDP-glucuronosyltransferases
-
Trans-Resveratrol (tRes) has been shown to have powerful antioxidant, anti-inflammatory, anticarcinogenic, and antiaging properties; however, its use as a therapeutic agent is limited by its rapid metabolism into its conjugated forms by UDP-glucuronosyltransferases (UGTs). The aim of the current study was to test the hypothesis that the limited bioavailability of tRes can be improved by modifying its structure to create analogs which would be glucuronidated at a lower rate than tRes itself. In this work, three synthetic stilbenoids, (E)-3-(3-hydroxy-4-methoxyphenyl)-2-(3,4,5-trimethoxyphenyl)acrylic acid (NI-12a), (E)-2,4-dimethoxy-6-(4-methoxystyryl)benzaldehyde oxime (NI-ST-05), and (E)-4-(3,5-dimethoxystyryl)-2,6-dinitrophenol (DNR-1), have been designed based on the structure of tRes and synthesized in our laboratory. UGTs recognize and glucuronidate tRes at each of the 3 hydroxyl groups attached to its aromatic rings. Therefore, each of the above compounds was designed with the majority of the hydroxyl groups blocked by methylation and the addition of other novel functional groups as part of a drug optimization program. The activities of recombinant human UGTs from the 1A and 2B families were examined for their capacity to metabolize these compounds. Glucuronide formation was identified using HPLC and verified by β-glucuronidase hydrolysis and LC-MS/MS analysis. NI-12a was glucuronidated at both the -COOH and -OH functions, NI-ST-05 formed a novel N-O-glucuronide, and no product was observed for DNR-1. NI-12a is primarily metabolized by the hepatic and renal enzyme UGT1A9, whereas NI-ST-05 is primarily metabolized by an extrahepatic enzyme, UGT1A10, with apparent Km values of 240 and 6.2 μM, respectively. The involvement of hepatic and intestinal UGTs in the metabolism of both compounds was further confirmed using a panel of human liver and intestinal microsomes, and high individual variation in activity was demonstrated between donors. In summary, these studies clearly establish that modified, tRes-based stilbenoids may be preferable alternatives to tRes itself due to increased bioavailability via altered conjugation.
- Greer, Aleksandra K.,Madadi, Nikhil R.,Bratton, Stacie M.,Eddy, Sarah D.,Mazerska, Zofia,Hendrickson, Howard P.,Crooks, Peter A.,Radominska-Pandya, Anna
-
p. 536 - 545
(2014/05/06)
-
- PEG-N2O4: An efficient nitrating agent for the selective mono- and dinitration of phenols under mild conditions
-
N2O4 was easily impregnated on polyethyleneglycol to give a stable reagent. The polyethyleneglycol-N2O4 (PEG-N2O4) system was used as an effective nitrating agent for the nitration of phenols. Mono- and dinitrophenols can be obtained via direct nitration of phenols in the presence of PEG-N2O4 at room temperature in moderate to high yields. Copyright Taylor & Francis Group, LLC.
- Zolfigol, Mohammad Ali,Madrakian, Elaheh,Ghaemi, Ezat,Niknam, Khodabakhsh
-
p. 3366 - 3374
(2008/12/22)
-
- Trichloroisocyanuric Acid/NaNO2/wet SiO2 as an Efficient System for the Selective Dinitration of Phenols under Solvent-free Conditions
-
Dinitrophenols can be obtained via direct nitration of phenols with trichloroisocyanuric acid, NaNO2 and wet SiO2 at room temperature under solvent-free conditions with moderate to high yields.
- Zolfigol, Mohammad Ali,Madrakian, Elaheh,Ghaemi, Ezat
-
p. 2222 - 2224
(2007/10/03)
-