Bioactivity-guided fractionation of the volatile oil of Angelica sinensis radix designed to preserve the synergistic effects of the mixture followed by identification of the active principles

► We use bioactivity-guided fractionation to find active compounds in A. sinensis oil. ► We apply a robotic solvent selection to obtain an optimal solvent system for CCC. ► CCC separations are guided by the bioactivity of the sample not a target compound. ► The sample bioactivity is preserved during CCC fractionation. ► Z-ligustilide and n-butylidenephthalide are the active principles in A. sinensis oil.