The hydroxynitrilelyase from Hevea brasiliensis not only catalyzes – according to the natural activity of this enzyme – the formation and cleavage of cyanohydrins but also the reaction of nitroalkanes with aldehydes (Henryreaction). This is the first example of an enzymatic nitroaldolreaction. With nitromethane and nitroethane a broad range of aldehydes can be transformed into the corresponding