Fig. 3: Photoenzymatic reduction of nitroarenes into aromatic azoxy and azo compounds.

Azoxy compound reaction conditions: white LEDs (1000 lx), 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), H₂O₂ (15^a or 45^b mM), bmGDH (2 µM) and BaNTR1 (10 µM). ^aThe numbers without brackets denote conversion; the conversion was determined by GC-MS (reaction time = 12 h). ^bThe numbers within brackets denote isolated yield; the isolated yield was calculated after workup and purification (reaction time = 24 h). Azo compound reaction conditions: white and red (660 nm) LEDs, dioxygen saturated 0.1 M MOPS buffer pH = 7 (1^a or 10^b mL), chlorophyll (0.5 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 was determined by GC-MS (total reaction time = 18 h). ^bThe numbers within brackets denote isolated yield; the isolated yield (reaction time = 24 h) was calculated after workup and purification. BaNTR1 nitroreductase from Bacillus amyloliquefaciens, bmGDH glucose dehydrogenase from Bacillus megaterium.