Objective: To optimize enrichment technology of total lignans from Arctii Fructus residue after subcritical extraction. Method: Taking yield of Arctii Fructus oil and the content of total lignans in residue as indexes

subcritical extraction solvent of Arctii Fructus was investigated by single factor test.Total lignans in residue was enriched by alcohol extraction and water precipitation method

process parameters was optimized by single factor tests.HPLC was employed to determine contents of arctiin and arctigenin with mobile phase of acetonitrile(A)-0.1% phosphoric acid solution(B) for gradient elution(0-5 min

30%-35%A;5-13 min

35%-45%A;13-15 min

45%-48%A;15-20 min

48%-53%A;20-29 min

53%-80%A;29-40 min

80%-100%A) and detection wavelength at 280 nm. Result: Butane was selected as extraction solvent for degreasing.Optimum enrichment process was as follows:reflux extracted thrice with 8 times the amount of 70% ethanol for 1 h each time

filtrate pressure recoveried to 0.5 g·mL-1

precipitation with 12 time the amount of water according to quantity of dregs

reflux boiling time of 60 minutes;purity of total lignans was more than 50%

transfer rate reached more than 80%. Conclusion: Alcohol extraction and water precipitation method is suitable for enrichment and purification of total lignans in Arctii Fructus

this optimized process is stable and feasible.