*2.1. Materials*

Aminoglutethimide (purity: >98.0%) was purchased from TCI, Japan. Caffeine (purity: >98%), nicotinamide (purity: >98%) and ethenzamide (purity: >97%) were purchased from Sigma Aldrich (Darmstadt, Germany). Millipore water from the Milli-Q system (Merck Millipore, Milli-Q Advantage, Darmstadt, Germany) was used for solubility determination and HPLC-grade solvents for the mechanochemical experiments.
