586-30-1Relevant articles and documents
Exploring the Selective Demethylation of Aryl Methyl Ethers with a Pseudomonas Rieske Monooxygenase
Lanfranchi, Elisa,Trajkovi?, Milo?,Barta, Katalin,de Vries, Johannes G.,Janssen, Dick B.
, p. 118 - 125 (2019/01/04)
Biocatalytic dealkylation of aryl methyl ethers is an attractive reaction for valorization of lignin components, as well as for deprotection of hydroxy functionalities in synthetic chemistry. We explored the demethylation of various aryl methyl ethers by using an oxidative demethylase from Pseudomonas sp. HR199. The Rieske monooxygenase VanA and its partner electron transfer protein VanB were recombinantly coexpressed in Escherichia coli and they constituted at least 25 % of the total protein content. Enzymatic transformations showed that VanB accepts NADH and NADPH as electron donors. The VanA–VanB system demethylates a number of aromatic substrates, the presence of a carboxylic acid moiety is essential, and the catalysis occurs selectively at the meta position to this carboxylic acid in the aromatic ring. The reaction is inhibited by the by-product formaldehyde. Therefore, we tested three different cascade/tandem reactions for cofactor regeneration and formaldehyde elimination; in particular, conversion was improved by addition of formaldehyde dehydrogenase and formate dehydrogenase. Finally, the biocatalyst was applied for the preparation of protocatechuic acid from vanillic acid, giving a 77 % yield of the desired product. The described reaction may find application in the conversion of lignin components into diverse hydroxyaromatic building blocks and generally offers potential for new, mild methods for efficient unmasking of phenols.
Process for the synthesis of biologically active oxygenated compounds by dealkylation of the corresponding alkylethers
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Page/Page column 8-9, (2008/06/13)
Alkoxy aromatic compounds are conveniently dealkylated to the corresponding phenolic compounds by treatment with aluminum chloride/N,N-dimethyl aniline complex. Aromatic poly O-demethylation is a unique feature of this invention. This process is applicable to the manufacture of polyphenols such as Resveratrol, Oxyresveratrol, Gnetol.
Baker's yeast-mediated enantioselective synthesis of the bisabolane sesquiterpenes (+)-curcuphenol, (+)-xanthorrhizol, (-)-curcuquinone and (+)-curcuhydroquinone
Fuganti, Claudio,Serra, Stefano
, p. 3758 - 3764 (2007/10/03)
Fermenting baker's yeast converts the unsaturated aldehydes 5a-c into the saturated alcohols 6a-c, respectively. The microbial saturation of substrates adsorbed on a nonpolar resin proceeds in high chemical yields and shows complete enantioselectivity in the formation of the (S)-(+) isomers. Enantiopure 6a-c are versatile chiral building blocks for the synthesis of bisabolane sesquiterpenes. Their usefulness is shown in the preparation of (S)-(+)-curcuphenol, (S)-(+)-xanthorrhizol, (S)-(-)-curcuquinone and (S)-(+)-curcuhydroquinone. The Royal Society of Chemistry 2000.