Chemoenzymatic preparation of a biologically active naphthoquinone from Tabebuia impetiginosa using lipases or alcohol dehydrogenases

Cancer chemopreventive agent (S)-5-hydroxy-2-(1-hydroxyethyl)naphtho[2,3-b]furan-4,9-dione and its counterpart (R)-acetate have been obtained through a lipase-catalyzed transesterification process in organic solvent. Candida antarctica lipase B and Pseudomonas cepacia lipase have demonstrated their potential as excellent biocatalysts for the production of enantiomerically pure compounds under mild reaction conditions. At the same time different commercially available alcohol dehydrogenases have been tested in the bioreduction of the corresponding naphthoquinone in an aqueous system. Biologically active (S)-alcohol has been isolated in enantiopure form with different conversion values depending on the biocatalyst employed and the reaction conditions.