Enzymatic production and isolation of d-amino acids from the corresponding 5-substituted hydantoins

Optimization of a heterogeneous reaction system for the production of optically activeD-amino acids using thermostableD-hydantoinase

“…In a D-hydantoinase-catalyzed reaction, a relatively moderate concentration (<100 g/L) of HPH has been used so far (Deepa et al, 1993;Lee and Lin, 1996;Olivieri et al, 1981), but few studies on the factors affecting the kinetics of the reaction system have been carried out.…”

“…Heterogeneous reaction systems containing solid substrate have been widely investigated in chemical reactions (Levenspiel, 1972), and a few examples have been reported in enzymatic reactions (Bailey and Ollis, 1986), including steroid transformation (Constantinides, 1980;Maxon et al, 1966) and hydrolysis of cellulosic materials (Ryu et al, 1982). In a D-hydantoinase-catalyzed reaction, a relatively moderate concentration (<100 g/L) of HPH has been used so far (Deepa et al, 1993;Lee and Lin, 1996;Olivieri et al, 1981), but few studies on the factors affecting the kinetics of the reaction system have been carried out.…”

The crystal structure and Raman spectrum of the sodium salt of 5-Acetic acid hydantoin

“…Hydantoins have many practical uses. They receive application as pharmaceuticals (e.g., phenytoin and fosphenytoin are used as anticonvulsants in the treatment of seizures and epilepsy [1][2][3][4], dantrolene is used as a muscle relaxant to treat, for instance, spasticity and ecstasy intoxication [5,6], and ropitoin is used as an antiarrhythmic drug [7], while several hydantoin derivatives have also been proposed for the treatment of cancer and AIDS [8][9][10][11]), as desinfectants, insecticides, herbicides and fungicides (as, for example, sulfochloranthine, imiprothrin and iprodione [12][13][14]), and as reactants in the synthesis of amino acids [15,16]. 5acetic acid hydantoin (2-(2,5-dioxoimidazolidin-4-yl)acetic acid; abbreviated 5AAH; Fig.…”

Modeling, simulation, and kinetic analysis of a heterogeneous reaction system for the enzymatic conversion of poorly soluble substrate

“…As an alternative approach, we carried out the enzyme reaction in a heterogeneous reaction system in which most of the substrate is present in suspended particles and optimized the reaction system (Lee and Kim, 1998). So far, the heterogeneous reaction system consisting of solid substrate has been attempted in steroid biotransformation (Constantinides, 1980;Maxon et al, 1966), and the hydantoinasecatalyzed reaction with moderate substrate concentration (Deepa et al, 1993;Lee and Lin, 1996;Olivieri et al, 1981), but systematic analyses on the kinetics of the reaction system have not been performed. Recently, a kinetic model was tested for ␣-chymotrypsin-catalyzed hydrolysis of benzylmethylmalonate (Wolff et al, 1997), and in this case, deactivation of the enzyme was not considered, and a very low concentration of solid substrate (∼2 g/L) was used.…”