Measurement of superoxide dismutase, catalase and glutathione peroxidase in cultured cells and tissue Nature Protocols A purine derivative, paraxanthine, promotes cysteine uptake for glutathione synthesis ScienceDirect Study finds Enfinity paraxanthine enhances cognitive and memory measures better than caffeine Inhibition of erythrocyte's catalase, glutathione peroxidase or peroxiredoxin 2 Impact on cytosol and membrane ScienceDirect A purine derivative, paraxanthine, promotes cysteine uptake for glutathione synthesis ScienceDirect Paraxanthine, a compound the body naturally produces when it breaks down caffeine, is starting to appear in energy drinks and even some coffee products as a potential caffeine alternative." Read our latest