(R)- and (S)-cyanohydrins using oxynitrilases in whole cells

Synthesis of Aromatic 1,2‐Amino Alcohols Utilizing a Bienzymatic Dynamic Kinetic Asymmetric Transformation

“…The reaction mixture was evaporated to give crude product (R)-6; yield: 883 mg (40 %); NMR data was consistent with those reported; [27] GC (gammaTFA) 1 bar H 2 , 175 8C isotherm, t R = 3.56 min, t S = 3.75 min., ee 79 % (GC); [a] 20 D : + 30.8 (c 1.0, EtOH); lit. [28] [a] [29] [a] 20 D : À37.6 (c 0.56, H 2 O); NMR data were consistent with those reported. [29] (S)-Octopamine [(S)-1] 4-Hydroxybenzaldehyde (0.977 g, 8.0 mmol) was dissolved in DMSO (16 mL) and mixed with glycine (30 g, 0.4 mol) together with lTA (1400 U) and l-TyrDC (Efi1, 40 U) in citrate/phosphate buffer pH 6.0 (37 mM citric acid, 126 mM Na 2 HPO 4 ).…”

Synthesis of (R)-2-trimethylsilyl-2-hydroxyl-propionitrile catalyzed by (R)-hydroxynitrile lyase fromPrunus japonicaseed meal

“…It has been found that increasing the aqueous phase content in an aqueous/organic biphasic system could enhance mass transfer in the case of (R)-HNL mediated reaction (Gerrits et al 2001). Furthermore, relatively high water content is necessary for the decomposition of acetone cyanohydrin at a reasonable rate (Kiljunen et al 1996). In addition, HNL may be denatured and inactivated once in contact with the interface of the two phases (Hickel et al 1998) and the higher the aqueous phase content, the less chance for the enzyme to contact the organic phase.…”

“…Enantiopure ketone-cyanohydrins could be converted to tertiary a-hydroxy acid, which are useful starting materials or synthetic intermediates for many chiral natural products (Mori 1989;Harada et al 1996). Due to the need of the corresponding (R,R )-dipeptide or expensive (S )-Hydroxynitrile lyase (HNL), the production of the corresponding (S )-ketone-cyanohydrins has been economically less attractive (Kiljunen et al 1996). Therefore, we focused on the preparation of optically active silicon containing (R )-ketonecyanohydrins.…”

Synthesis of (R)-2-trimethylsilyl-2-hydroxyl-ethylcyanide catalyzed with (R)-oxynitrilase from loquat seed meal

“…Gerrits et al (2001) found that increasing the aqueous phase content in an aqueous/organic biphasic system could enhance mass transfer in the case of a (R)-oxynitrilasemediated reaction. In addition, a relatively high water content is prerequisite to the decomposition of acetone cyanohydrin at a reasonable rate (Kiljunen & Kanerva 1996). Both factors contribute to the increase of the initial rate with increasing the volume ratio of aqueous to organic phase.…”