Fig. 2: Photoenzymatic reduction of nitroarenes into aromatic amines.

Reaction conditions: white LEDs (1000 lx), anaerobic (N₂) 0.1 M MOPS buffer pH = 7 (1^a or 10^b mL), chlorophyll (0.25 mM), nitroarene (5^a or 15^b mM, 10% DMSO), NAD⁺ (0.5 mM), glucose (50 mM), bmGDH (2 µM) and BaNTR1 (10 µM). ^aThe numbers without brackets denote conversion; the conversion ([product/initial substrate]) was determined by GC–MS (reaction time = 18 h), using toluene as internal standard. ^bThe numbers within brackets denote isolated yield; the isolated yield (reaction time = 24 h) was calculated after workup and purification. ^cFrom the corresponding dinitrobenzene substrate (1f or 1ab). ^dFrom the corresponding nitroaniline substrate. ^eFrom nitroaniline 1t. ^fFrom nitroaniline 1u. For the corresponding nitro compounds 1a–1aj, see Suppl. Fig. 2. BaNTR1 nitroreductase from Bacillus amyloliquefaciens, bmGDH glucose dehydrogenase from Bacillus megaterium.