Neuronal SH‐SY5Y cells transfected with either the wild‐type or the 717 valine‐to‐glycine amyloid precursor protein mutated gene are used as an AD model and treated with 5‐(4ʹ‐hydroxyphenyl)‐γ‐valerolactone, 5‐(3ʹ,4ʹ‐dihydroxyphenyl)‐γ‐valerolactone and 5‐(3ʹ‐hydroxyphenyl)‐γ‐valerolactone‐4ʹ‐sulfate. The gene discussed is TDO2; the disease is Alzheimer disease.