Redox Biocatalysis

Site‐Directed Mutagenesis Studies on the Toluene Dioxygenase Enzymatic System: Role of Phenylalanine 366, Threonine 365 and Isoleucine 324 in the Chemo‐, Regio‐, and Stereoselectivity

“…[27] Various rotamers were considered for some of the amino acids in the binding site: Glu 215 (8) (2). The mutated residues and those in contact with them and with the substrate at the same time were set free to move during the docking runs.…”

“…[1] More than 400 cis-cyclohexadienediols have been reported so far, with the methyl and halogen substituted ones (1, X= CH 3 or Cl, Br, I) being the most used for synthetic preparations. [2] These compounds are prepared from the corresponding arenes using Rieske non-heme iron dependent dioxygenases, which are responsible for the first step in the microbial degradation of aromatic arenes. [3] To date, no other non-biocatalytic chemical method for their production at a preparative scale is known.…”

Transesterifications and Peracid‐Assisted Oxidations in Aqueous Media Catalyzed by Mycobacterium smegmatis Acyl Transferase

“…Several examples of the discoloration of dyes, decontamination, tooth whitening, bleaching, or surface disinfection have been reported at the patent level. [5,6] However, despite the foreseeable interest in MsAcT for practical synthetic biocatalysis in aqueous media, which provides virtually unique and new properties among hydrolases, its synthetic potential has surprisingly not been explored so far. The possibility of the addition of a new hydrolase to the portfolio that could catalyze synthetic reactions in aqueous solutions Hydrolases catalyze synthetic reactions in nonaqueous media, whereas they perform hydrolysis under aqueous solutions.…”

“…[11] Apart from these transesterification concepts for different chemical purposes, asymmetric synthesis, multistep aqueousbased processes, downstream unit operations, etc, MsAcT also displays perhydrolase activity and is thus able to form organic peracids in aqueous solutions as previously reported. [4][5][6] With these considerations in mind, the oxidation of furfural to furoic acid in aqueous solution was assessed for the first time. Herein, two different acyl donors, ethyl acetate and dimethyl carbonate (DMC), were used successfully.…”

Novel chemoenzymatic oxidation of amines into oximes based on hydrolase-catalysed peracid formation

“…18 Interestingly, lipases have expanded their versatility in synthetic chemistry taking advantage of their key role in global redox transformations. 19 These transformations are possible based on a hydrolase-catalysed perhydrolysis reaction over a carboxylic acid or ester, resulting in the formation of a reactive peracid intermediate able to oxidise alkenes [20][21][22][23][24][25][26] or ketones [27][28][29][30][31][32] into epoxides or esters, respectively (Scheme 1). From all the tested enzymes, Candida antarctica lipase type B (CAL-B) has usually displayed the best activities under different reaction conditions.…”