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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 CC 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.

Lignocellulose materials are potentially valuable resources for transformation into many bio-products. However, because of the difficulty in fractionating them into cellulose, hemicellulose, and lignin by a simple method directly from wood biomass, their economical conversion into high value-added products has been greatly limited. We found that N-methyl-N-(2-methoxyethyl)pyrolidin-1-ium 2,6-diaminohexanoate ([P1ME][Lys]) dissolved lignin very well below 60 °C, but that 80 °C was required for it to dissolve cellulose. Taking advantage of this difference in dissolution ability, direct extraction of lignin from wood biomass has been accomplished under mild conditions without the use of any hazardous reagents. Since lignin acts as the essential glue that binds cellulose and hemicellulose and gives plants their structural integrity, we have achieved the demonstration of the sacrifice-free separation of cellulose, hemicellulose, and lignin from wood biomass (Japanese cedar: Cryptomeria japonica).

Reduction of the CC bond of verbenone by a reductase from the cultured cells of Nicotiana tabacuminvolves syn-addition of the hydrogen atom to the re-reface of the double bond; the hydrogen atoms participating in the reduction at C-2 and C-3 of verbenone originate from the pro-4Shydrogen of NADPH and the medium, respectively.

The role of divalent metal ions in the biosynthesis of cyclic monoterpenoids has been investigated by an analysis of the 31P and 13C NMR spectra of geranyl diphosphate (GPP) in the presence and in the absence of Mg2+. This study revealed that Mg2+ binds to the diphosphate moiety of GPP in the ratio of 1 : 1, equidistantly from both phosphorus atoms, and that Mg2+ chelation weakens the C(1 )–O(5) bond of GPP, facilitating elimination of the diphosphate group.