621-59-0Relevant articles and documents
One-Pot Biocatalytic In Vivo Methylation-Hydroamination of Bioderived Lignin Monomers to Generate a Key Precursor to L-DOPA
Birmingham, William R.,Galman, James L.,Parmeggiani, Fabio,Seibt, Lisa,Turner, Nicholas J.
, (2022/01/13)
Electron-rich phenolic substrates can be derived from the depolymerisation of lignin feedstocks. Direct biotransformations of the hydroxycinnamic acid monomers obtained can be exploited to produce high-value chemicals, such as α-amino acids, however the reaction is often hampered by the chemical autooxidation in alkaline or harsh reaction media. Regioselective O-methyltransferases (OMTs) are ubiquitous enzymes in natural secondary metabolic pathways utilising an expensive co-substrate S-adenosyl-l-methionine (SAM) as the methylating reagent altering the physicochemical properties of the hydroxycinnamic acids. In this study, we engineered an OMT to accept a variety of electron-rich phenolic substrates, modified a commercial E. coli strain BL21 (DE3) to regenerate SAM in vivo, and combined it with an engineered ammonia lyase to partake in a one-pot, two whole cell enzyme cascade to produce the l-DOPA precursor l-veratrylglycine from lignin-derived ferulic acid.
Preparation method of 3-hydroxy-4-methoxyphenylpropylaldehyde
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Paragraph 0048-0054; 0058-0065; 0068-0075; 0078-0085, (2021/11/10)
The invention provides a preparation method of 3-hydroxy-4-methoxyphenylpropylaldehyde. The preparation method comprises the following steps: 1, ring opening: subjecting sassafras oil, methanol and an alkaline reagent to a reaction to obtain a phenol potassium salt solution; 2, etherification: subjecting the phenol potassium salt solution to reacting with an excessive methylation reagent to obtain mixed ether; 3, hydrolysis: subjecting the mixed ether to reacting with alcohol, water and a catalyst to obtain a hydrolyzed oil phase; 4, esterification: subjecting the hydrolyzed oil phase to reacting with acetic anhydride to obtain an acetyl intermediate product; 5, ozonization and reduction: subjecting the acetyl product to reacting with ozone, and adding a pyrosulfite solution for reduction to obtain a reduced oil phase; 6, alcoholysis: performing alcoholysis on the oil phase obtained in the step 5 to obtain a crude isovanillin product; 7, condensation; and 8, hydrogenation. The preparation method solves the problems that isovanillin is few in source and high in price, and production of a 3-hydroxy-4-methoxyphenylpropyl aldehyde intermediate is limited in the prior art, and has the advantages of being high in yield and low in cost.
Oxygen-Free Regioselective Biocatalytic Demethylation of Methyl-phenyl Ethers via Methyltransfer Employing Veratrol- O-demethylase
Grimm, Christopher,Lazzarotto, Mattia,Pompei, Simona,Schichler, Johanna,Richter, Nina,Farnberger, Judith E.,Fuchs, Michael,Kroutil, Wolfgang
, p. 10375 - 10380 (2020/10/02)
The cleavage of aryl methyl ethers is a common reaction in chemistry requiring rather harsh conditions; consequently, it is prone to undesired reactions and lacks regioselectivity. Nevertheless, O-demethylation of aryl methyl ethers is a tool to valorize natural and pharmaceutical compounds by deprotecting reactive hydroxyl moieties. Various oxidative enzymes are known to catalyze this reaction at the expense of molecular oxygen, which may lead in the case of phenols/catechols to undesired side reactions (e.g., oxidation, polymerization). Here an oxygen-independent demethylation via methyl transfer is presented employing a cobalamin-dependent veratrol-O-demethylase (vdmB). The biocatalytic demethylation transforms a variety of aryl methyl ethers with two functional methoxy moieties either in 1,2-position or in 1,3-position. Biocatalytic reactions enabled, for instance, the regioselective monodemethylation of substituted 3,4-dimethoxy phenol as well as the monodemethylation of 1,3,5-trimethoxybenzene. The methyltransferase vdmB was also successfully applied for the regioselective demethylation of natural compounds such as papaverine and rac-yatein. The approach presented here represents an alternative to chemical and enzymatic demethylation concepts and allows performing regioselective demethylation in the absence of oxygen under mild conditions, representing a valuable extension of the synthetic repertoire to modify pharmaceuticals and diversify natural products.