Nicotinamide adenine dinucleotide as a photocatalyst

Area of Science:

• Biochemistry
• Photocatalysis
• Green Chemistry

Background:

• Nicotinamide adenine dinucleotide (NAD+) is essential for cellular redox reactions, energy transduction, and genomic stability.
• NAD+ traditionally functions as a cofactor in biocatalysis.

Purpose of the Study:

• To explore the novel function of NAD+ as a molecular photocatalyst.
• To investigate the light absorption and electronic properties of NAD+.
• To demonstrate NAD+-driven photocatalytic redox reactions and their integration with biocatalysis for solar-to-chemical conversion.

Main Methods:

• Spectroscopic and electrochemical analyses to determine NAD+'s optical and electronic properties.
• Photocatalytic experiments demonstrating O2 reduction, H2O oxidation, and nanoparticle formation.
• Integration of NAD+-based photocatalysis with biocatalysis for trans-hydrogenation reactions.

Main Results:

• NAD+ exhibits robust photostability under UV-Vis-NIR irradiation.
• NAD+ directly photoactivates oxidoreductases.
• Achieved record-high turnover frequency (1263.4 h⁻¹) and total turnover number (1692.3) for light-driven biocatalytic trans-hydrogenation.

Conclusions:

• NAD+ possesses significant photocatalytic activity, expanding its known cellular functions.
• The integration of NAD+-based photocatalysis and biocatalysis offers a highly efficient pathway for solar-to-chemical energy conversion.
• This research opens new avenues for sustainable chemical synthesis using light energy.