Diastereoselective reduction of β-keto carbonyl compounds by cultured plant cells

The diastereoselective reduction of β-keto carbonyl compounds such as 2-benzamidomethyl-3-oxobutanoates and 2-methyl-2-(2-propenyl)cyclopentan-1,3-dione by cultured cells of higher plants was investigated. The reduction of the 2-benzamidomethyl-3-oxobutanoates by Parthenocissus tricuspidata diastereoselectively produced the (2R,3S)-2-benzamidomethyl-3-hydroxybutanoates, whereas the reduction by Gossypium hirsutum gave the (2S,3S)-2-benzamidomethyl-3-hydroxybutanoates. The (2R,3S)/(2S,3S) predominance in the reduction with Nicotiana tabacum, Glycine max, and Catharanthus roseus was reversed by the change in the structure of the alkoxyl group in the substrate. On the other hand, the reduction of 2-methyl-2-(2-propenyl)cyclopentan-1,3-dione by P. tricuspidata produced (2R,3S)-3-hydroxy-2-methyl-2-(2-propenyl)cyclopentan-1-one, whereas the reaction by N. tabacum, G. max, C. roseus, and G. hirsutum gave (2S,3S)-3-hydroxy-2-methyl-2-(2-propenyl)cyclopentan-1-one.