Preparation of decursin and treatments

Decursin was synthesized using decursinol isolated from the dried roots of Korean angelica (A. gigas). Decusin was prepared by Professor Song's laboratory at the College of Pharmacy, Chungnam National University, Deajeon, as previously described (26). Briefly, in order to synthesize decursin, decursinol was dissolved in dry methylene chloride and cooled down in an ice bath. Dicyclohexylcarbodiimide, 3,3-dimethylacrylic acid, and 4-dimethylaminopyridine were then added with stirring. The reaction mixture was stirred at room temperature for 24 h and filtered. The filtrate was evaporated under reduced pressure and purified by flash column chromatography to obtain decursin as a white powder. The structure of decursin was confirmed by comparing nuclear magnetic resonance and mass spectrometry spectra. Decursin was dissolved in dimethyl sulfoxide (DMSO); in all experiments the concentration of DMSO was limited to 0.1%. The dose of decursin 50 or 100 µM was chosen based on previous studies (27,28).