- Pyrroloquinoline quinone (henceforth PQQ) is a small quinone molecule which has the ability to be a REDOX agent, capable of reducing oxidants (an antioxidant effect) and then being recycled by glutathione back into an active form. It appears to be quite stable as it can undergo several thousand cycles before being used up, and it is novel since it associates with protein structures inside the cell (some antioxidants, mostly notably carotenoids like β-carotene and Astaxanthin, are located at specific areas of a cell where they exert proportionally more antioxidant effects due to proximity; PQQ seems to do this near proteins like carotenoids do so at the cell membrane).
- The aforementioned REDOX functions can alter protein function and signalling pathways, and while there is a lot of promising in vitro (outside of a living model) research on what it could do there are only a few promising results of PQQ supplementation, mostly related to either altering some signalling pathways or via its benefits to mitochondria (producing more of them and increasing their efficiency).
- It is a coenzyme in bacteria (so, to bacteria, this would be something like a B-vitamin) but this role does not appear to extend to humans. Since this does not extend to humans, the designation of PQQ as a vitamin compound has fallen through and it is only considered ‘vitamin-like’ at best.