In the title compound, [Cu(2)(C(8)H(11)N(2)O(3)S)(2)Cl(2)], the Cu atoms are five-coordinated in a distorted square-pyramidal geometry by three donor atoms of the deprotonated anionic 2-(2-pyridylmethyl-amino)ethanesulfonate (pmt) ligand and two Cl atoms. The Cl atoms bridge two Cu atoms, giving a binuclear structure; the centroid of the Cu(2)Cl(2) ring lies on a crystallographic center of inve...

Polymethylated Flavonols, Identification, Enzymatic Synthesis, O-Methyltransferase, Chrysosplenium americanum, Saxifragaceae The major flavonoid constituents of Chrysosplenium americanum (Saxifragaceae) were identi­ fied by UV-, NMRand mass spectroscopy and the analysis of their hydrolytic products. They consisted of two 2'-0-/?-D-glucosides of partially methylated 2'-hydroxyquercetin and four ...

In this work, we present a comparative case study of "ortho-" and "meta-nitrated" catecholic inhibitors of catechol-O-methyltransferase (COMT), with regard to their interaction with the catalytic site of the enzyme and the in vitro regioselective formation of their mono-O-methyl ether metabolites. In particular, the effects of altering the attachment position of the inhibitors' side-chain subst...

Catechol-O-methyltransferase (COMT, EC 2.1.1.6) plays a crucial role in dopamine metabolism which has intimately linked this enzyme to some neurodegenerative diseases, such as Parkinson's disease. In recent years, in the attempt of developing new therapeutic strategies for Parkinson's disease, there has been a growing interest in the search for effective COMT inhibitors. In order to do so, larg...

In an effort to investigate catechol methyltransferase activity in sources other than mammalian tissues and cells, a high level of enzyme activity was found in the yeast fungus Candida tropicalis CBS 94. Partial purification of the enzyme (approx. 550 fold with a recovery of 7%) could be achieved by using ion-exchange and gel filtration techniques. The molecular weight was estimated at 32,000 +...

Ubiquinone functions in the mitochondrial electron transport chain. Recent evidence suggests that the reduced form of ubiquinone (ubiquinol) may also function as a lipid soluble antioxidant. The biosynthesis of ubiquinone requires two O-methylation steps. In eukaryotes, the first O-methylation step is carried out by the Coq3 polypeptide, which catalyzes the transfer of a methyl group from S-ade...

Coq3 O-methyltransferase carries out both O-methylation steps in coenzyme Q (ubiquinone) biosynthesis. The degree to which Coq3 O-methyltransferase activity and expression are dependent on the other seven COQ gene products has been investigated. A panel of yeast mutant strains harboring null mutations in each of the genes required for coenzyme Q biosynthesis (COQ1-COQ8) have been prepared. Mito...

The Flavivirus NS5 protein possesses both (guanine-N7)-methyltransferase and nucleoside-2'-O methyltransferase activities required for sequential methylation of the cap structure present at the 5' end of the Flavivirus RNA genome. Seventeen mutations were introduced into the dengue virus type 2 NS5 methyltransferase domain, targeting amino acids either predicted to be directly involved in S-ade...