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Ability of Different Biomaterials to Enantioselectively Catalyze Oxidation and Reduction Reactions
Author(s) -
Nagaoka Hiroyuki
Publication year - 2008
Publication title -
biotechnology progress
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.572
H-Index - 129
eISSN - 1520-6033
pISSN - 8756-7938
DOI - 10.1021/bp0342046
Subject(s) - nad+ kinase , substrate (aquarium) , chemistry , cofactor , catalysis , reactivity (psychology) , stereospecificity , enzyme , stereochemistry , medicinal chemistry , organic chemistry , biology , medicine , ecology , alternative medicine , pathology
We studied the ability of different biomaterials to enantioselectively catalyze oxidation or reduction reactions with the help of substrate rac ‐1‐ m or p ‐ArCH(OH)Me and the 1‐ o ‐ArC(O)Me derivatives. Apoenzyme (NAD(P) + ‐dependent secondary alcohol dehydrogenase(NAD(P)‐E)) and cofactor (NAD(P) + ) were activated by preincubating immobilized aqueous plant leaf (e.g., young wheat leaves), cereal tissue (wheat bran), vegetable (e.g., carrot), and seaweed (e.g., wakame seaweed) solutions, and the NAD(P)‐E oxidized only ( R )‐isomers highly enantioselectively. Thus, greater than 99% ee(s) of ( S )‐isomers ( 1m – 5m and 1p – 5p ) can be obtained from corresponding rac ‐1‐ m or p ‐ArCH(OH)Me. Further, immobilized chlorella cells and immobilized bakerapos;s yeast can reduce highly stereoselectively; greater than 99% ee(s) of ( S )‐isomers ( 1o – 5o ) can be obtained from corresponding 1‐ o ‐ArC(O)Me. Specific use of each isomer (( S )‐ 6 and ( R )‐ 6 ) with greater than 99% ee(s) of racemic ‐1–2‐NpCH(OH)Me becomes possible through selective use of NAD(P)‐E eluted from artemisia vulgaris indica leaves and young wheat leaves. We suggest that the pH of the reaction media can determine not only the direction of NAD(P)‐E, toward enantioselectively catalyzed oxidation (pH > 7.0) or reduction reaction (pH < 7.0), but also the regioselective reactivity of NAD(P)‐E to the substrate o ‐ (pH < 7.0), m ‐, and p ‐substituted groups (pH > 7.0). Thus, in comparison to current biocatalysts, several biomaterials can serve as asymmetric reagent bases, providing easily obtained, low‐cost natural catalysts with stereoselectivity, regioselectivity, and substrate specificity that work under mild conditions for asymmetric synthesis of organic compounds.