Valorization of 5-hydroxymethylfurfural by biocatalyzed reduction and amination

The growing interest in the preparation of non-oil chemical compounds has led to the development of carbohydrate transformations in valuable chemicals. This trend is highlighted by the production of several furan derivatives used for the preparation of new polymeric materials such as polyesters, polyamides and polyurethanes. 5-hydroxymethyl furfural (HMF), 1, is a common furan aldehyde derived from dehydration of pentoses and hexoses during pretreatment and hydrolysis of lignocellulosic biomass [1]. This compound plays an important role as scaffold for the synthesis of di-substituted furan derivatives, that are also important intermediates for the preparation of pharmacologically active compounds with a broad spectrum of biological activity. In this work, the synthesis of two industrial relevant building blocks was targeted through biocatalyzed reactions on 1. In particular, compound 2 was obtained by reduction catalyzed by plant tissue, while compound 3 was obtained by amination transfer reaction in the presence of immobilized transaminase enzymes, TA-IMB [2]. Among different biocatalysts, plants are excellent alternatives to the use of isolated enzymes, since the oxido-reductase, cofactor and its regenerate system are all located in the cell and the addition of the expensive cofactor can be avoided [3]. Transaminase enzymes are biocatalysts of great importance for the selective and efficient transformation of ketones and aldehydes into the corresponding amines [4]. In this study, the feasibility of direct use of different parts of plants for bioreduction and the application of immobilized transaminase enzymes have been investigated and preliminary results will be presented.