TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: The method comprises adding 180 liter of 90% ethanol solution into 20 kg spikenard medicine; refluxing and extracting 3 times for 2 hours each time; combining extracting liquid; concentrating and recycling ethanol to obtain 3 liter extract; adding 7 liter of water into extract; fully stirring and dispersing; adding 10 liter of ethyl acetate; fully stirring and extracting; separating liquid; concentrating and recycling ethyl acetate in organic phase to obtain 950 g of extract; fully mixing 1900 g of extract with 60-80-mesh chromatographic silica gel; drying and grinding to powder to obtain 2400 g mixed sample silica gel; weighing 12 kg of 200-300-mesh chromatography silica gel to silica gel column; sampling according to weight ratio of sampling amount to column-packed silica gel of 1:5; eluting with petroleum ether-ethyl acetate solution according to volumetric ratio of 8:1 while monitoring with thin layer chromatography method; absorbing chromatography eluent and nardosinone comparison product; sampling on same silica gel GF254 thin plate; spreading with petroleum ether-ethyl acetate according to volumetric ratio of 4:1 as spreading agent; observing in UV lamp of 254 nm, such that when spots in same color are displayed in same retention (Rf) value position of eluent and comparison product, collecting eluent in product segment and concentrating until solid starts to crystallized; standing; cooling and crystallizing for 8-10 hours; recrystallizing according to specific purity of crystal until purity is greater than or equal to 98.5%; filtering and drying solid at 80 degrees C for 6 hours to obtain nardosinone product; heating and dissolving crude nardosinone product with petroleum ether-ethyl acetate solution according to volumetric ratio of 4:1; concentrating until solid starts to crystallized; standing; cooling and crystallizing for 8 hours; drying solid at 80 degrees C for 6 hours to obtain 105 g of nardosinone product with purity of 99.6% as indicated by HPLC analysis.