Vegetables of the family Apiaceae are promising biocatalysts for the enantioseparation of bicyclo[3.3.1]nonane- 2,6-dione

Abstract

Enzymes catalyzed transformations are widely used in organic chemistry nowadays. Many enzymes exhibit a high degree of enantioselectivity. Thus, they are particularly attractive for the enantioseparation of racemic mixtures. Previously the (+) and (−)-enantiomers of bicyclo[3.3.1]nonane-2,6-dione were separated using a horse liver alcohol dehydrogenase catalyzed reduction coupled with the regeneration of the coenzyme NAD by dithionite or ethanol [1]. For the stereospecific reduction and the resolution of the enantiomers of that compound, baker's yeast were also applied 2 and 3. However, intact plant materials could also be used for that purpose. The aim of this work was to test various vegetables as biocatalysts for the enantioseparation of bicyclo[3.3.1]nonane-2,6-dione. We screened ten various vegetables and found that the best results were obtained using the ones of the family Apiaceae, i.e. the roots of parsnip (Pastinaca sativa), celery (Apium graveolens), parsley (Petroselinum crispum) and carrot (Daucus carota). We optimized the reaction temperature, duration and the amount of vegetables. We obtained (+)-enantiomer of bicyclo[3.3.1]nonane-2,6-dione in the yield of 50% and with the excellent enantiomeric excess of 90–98% by using the roots of Apium graveolens. This biotechnological process is ecofriendly and cheap, the isolation of the final product is easy, and vegetables as biocatalysts are easy available.