Separation Of Glucosinolates From Rapeseed By Countercurrent Chromatography

Glucosinolates are anionic, hydrophilic plant secondary metaboliteswhich are of particular interest due to their role in the prevention ofcancer and other chronic and degenerative diseases. Therefore, it wasvery important to separate and identify glucosinolates from cruciferousplants, which would be benefit to the development of products involvingglucosinolates. Countercurrent chromatography (CCC) is a liquid-liquidpartition chromatography that no solid matrix is required, and can reachhigh efficient separation and recovery. In the present study, two kind ofCCC, high-speed countercurrent chromatography (HSCCC) and slowrotary countercurrent chromatography (SRCCC) were applied to separateglucosinolates in the rapeseed extract.A CCC solvent system composed of butanol-acetonitrile-10%ammiaonia sulfate (1:0.5:2.2) was found as an excellent solvent systemto separate the glucosinolates in the crude extract from rapeseed.Using HSCCC-D200 with a 200 ml column, 400mg crude extract from rapeseed was separated to yield 13.6 mg A2(Z-(N)-3-butenylglucosinolate) and 47.2mg B(2-hydroxy-3-butenylglucosinolate) in 8.5 hours. Using SRCCC-D3400with a 3400 ml column, 7g crude extract from rapeseed was separate toyield 86.3mg A2 and 521.4mg B in 22 hours. The parameters influencingthe CCC separation were studied to optimum the separation conditions.The glucosinolate components from CCC separations were purified bypreparative HPLC to yield three glucosinolate monomers:E-(N)-3-butenylglucosinolate, Z-(N)-3-butenylglucosinolate and2-Hydroxy-3-butenylglucosinolate.E-(N)-3-butenylglucosinolateZ-(N)-3-butenylglucosinolate 2-hydroxy-3-butenylglucosinolateThe scale-ups of CCC were studied. Using HSCCC-D1200 with1200ml column, 365.4mg B could be obtained from the sample of 7gcrude extract in 23 hours. Using SRCCC-22L with 22L column, 3.37g Bcould be obtained from 50g crude extract in 62 hours. The separationswere scaled up to grams with HSCCC and 10 grams with SRCCC,respectively.