Novel reductase participation in the syn-addition of hydrogen to the C
C bond of enones in the cultured cells of Nicotiana tabacum
Abstract
A reductase isolated from cultured cells of Nicotiana tabacum has been characterized and used in the reduction of a CC bond adjacent to a carbonyl group. The stereochemistry of the latter reaction has been investigated by 2H NMR and mass spectroscopy. It was found that the reductase reduces stereospecifically the C
C bond of verbenone and carvone by syn addition of hydrogen from the re face at the β-position and the re face at the α-position to the carbonyl group; the hydrogen atoms participating in the enzymatic reduction at the α- and β-positions originate from the medium (H2O) and the pro-4S hydrogen of NADPH, respectively.