RESUMEN
Glycerol is a byproduct of biodiesel production and is generated in large amounts, which has resulted in an increased interest in its valorization. In addition to its use as an energy source directly, the chemical modification of glycerol may result in value-added derivatives. Herein, acid phosphatases employed in the synthetic mode were evaluated for the enzymatic phosphorylation of glycerol. Nonspecific acid phosphatases could tolerate glycerol concentrations up to 80â wt % and pyrophosphate concentrations up to 20â wt % and led to product titers up to 167â g L-1 in a kinetic approach. In the complementary thermodynamic approach, phytases were able to condense glycerol and inorganic monophosphate directly. This unexpected behavior enabled the simple and cost-effective production of rac-glycerol-1-phosphate from crude glycerol obtained from a biodiesel plant. A preparative-scale synthesis on a 100â mL-scale resulted in the production of 16.6â g of rac-glycerol-1-phosphate with a reasonable purity (≈75 %).
Asunto(s)
Fosfatasa Ácida/química , Glicerol/química , Glicerofosfatos/química , Fosfatos/química , Biocombustibles , FosforilaciónRESUMEN
Ene-reductases from the 'Old Yellow Enzyme' family of flavoproteins catalyze the asymmetric reduction of various α,ß-unsaturated compounds at the expense of a nicotinamide cofactor. They have been applied to the synthesis of valuable enantiopure products, including chiral building blocks with broad industrial applications, terpenoids, amino acid derivatives and fragrances. The combination of these highly stereoselective biocatalysts with a cofactor recycling system has allowed the development of cost-effective methods for the generation of optically active molecules, which is strengthened by the availability of stereo-complementary enzyme homologues.
Asunto(s)
Alquenos/química , Alquenos/metabolismo , Biotecnología/métodos , NADPH Deshidrogenasa/metabolismo , Aminoácidos/metabolismo , Biocatálisis , Nitrilos/química , Perfumes/síntesis química , Perfumes/química , Estereoisomerismo , Terpenos/síntesis química , Terpenos/químicaRESUMEN
Total asymmetric synthesis of two components of Panax ginseng showing antitumor activity, i.e., (3R,9R,10R)- and (3S,9R,10R)-Panaxytriol and of both enantiomers of Falcarinol was accomplished. Due to the fact that the synthetic strategy was based on enantioconvergent biotransformations, the occurrence of any undesired stereoisomer was entirely avoided. The absolute configuration of naturally occurring Panaxytriol was confirmed to be (3R,9R,10R) on the basis of optical rotation values. It was shown that enzyme-triggered cascade reactions represent a valuable tool for the synthesis of natural products.