Superoxide as an obligatory, catalytic intermediate in photosynthetic reduction of oxygen by adrenaline and dopamine.
The superoxide anion radical is known to be the first product of photosynthetic reduction of oxygen mediated by a variety of electron carriers. The effectiveness of many of these electron carriers as herbicides, and the toxicity of the superoxide they produce, have been suggested to rule out oxygen reduction as a physiological component of normal photosynthesis. Here results with isolated spinach
