Enzymatic Synthesis of Valuable Bioactive Compounds

sustainable and convenient, one-pot two-enzyme method for the glucosylation of arylalkyl alcohols was developed (Scheme 1). The reaction scheme was based on a transrutinosylation catalyzed by a rutinosidase from A. niger using the cheap and commercially available flavonoid rutin as glycosyl donor, followed by a selective \u2018trimming\u2019 of the rutinoside unit, catalyzed by a rhamnosidase from A. terreus. Both these enzymes were available to us as heterologous proteins produced by a recombinant strain of P. pastoris. This process allowed the facile preparation of several natural bioactive glucosides, which could be isolated in up to 80% yield without the need of silica-gel chromatography

Laccase-catalyzed dimerization of glycosylated lignols

Phenylpropanoid glucosides (PPGs) are naturally occurring and bioactive phenolic derivatives, largely distributed in plants. In this work different PPGs have been chemically or enzymatically synthesized from the lignols coniferyl and p-coumaryl alcohols as substrates for a laccase-catalyzed oxidative coupling. The biooxidation of these PPGs has been investigated here and novel dihydrobenzofuran-based structurally modified analogues have been isolated and characterized. Specifically, the presence of a carbohydrate moiety increased the water solubility of these compounds and reduced the number of dimeric products, as pinoresinol-like structures could not be formed. Looking for a possible sugar-promoted stereochemical enrichment of the obtained diastereomeric mixtures of dimers, different carbohydrate moieties (D-glucose, L-glucose and the disaccharide rutinose) were considered and the respective d.e. values of the dimeric products were measured by 1H NMR and HPLC. However, it was found that the sugar substituent had a minor effect on the stereochemical outcome of the radical coupling reactions, the best measured result being a d.e. value of 21%

A Sustainable One-Pot, Two-Enzyme Synthesis of Naturally Occurring Arylalkyl Glucosides

A sustainable, convenient, scalable, one-pot, two-enzyme method for the glucosylation of arylalkyl alcohols was developed. The reaction scheme is based on a transrutinosylation catalyzed by a rutinosidase from A.\u2005niger using the cheap commercially available natural flavonoid rutin as glycosyl donor, followed by selective "trimming" of the rutinoside unit catalyzed by a rhamnosidase from A.\u2005terreus. The process was validated with the syntheses of several natural bioactive glucosides, which could be isolated in up to 75\u2009% yield without silica-gel chromatography