The search for affordable, green
biocatalytic processes is a challenge
for chemicals manufacture. Redox biotransformations are potentially
attractive, but they rely on unstable and expensive nicotinamide coenzymes
that have prevented their widespread exploitation. Stoichiometric
use of natural coenzymes is not viable economically, and the instability
of these molecules hinders catalytic processes that employ coenzyme
recycling. Here, we investigate the efficiency of man-made synthetic
biomimetics of the natural coenzymes NAD(P)H in redox biocatalysis.
Extensive studies with a range of oxidoreductases belonging to the
“ene” reductase family show that these biomimetics are
excellent analogues of the natural coenzymes, revealed also in crystal
structures of the ene reductase XenA with selected biomimetics. In
selected cases, these biomimetics outperform the natural coenzymes.
“Better-than-Nature” biomimetics should find widespread
application in fine and specialty chemicals production by harnessing
the power of high stereo-, regio-, and chemoselective redox biocatalysts
and enabling reactions under mild conditions at low cost