Separation And Purification Of Sulforaphane By Macroporous Resins And Counter-Current Chromatography

At present,sulforaphane(CH₃S(O)CH₂CH₂CH₂CH₂N=C=S)is considered as one of natural products which have wonderful effects on the prevention and treatment to cancer,and it is the strongest inducer of phaseâ…¡enzymes in nature.With the study of sulforaphane deep-going, it can not only increase the antioxidant ability of human body,but inhibit and kill cancer cells.Considering its significant effect on the prevention and treatment of cancer in the future,researchers have been regarding sulforaphane as the hot spot.The main contents of the papers are purifying sulforaphane from broccoli seeds by macroporous resins and preparative High-speed counter-current chromatography.In this study,the adsorption and desorption properties of sulforaphane on macroporous resins were investigated.Analysis revealed that SP850 resin was most effective in the separation of sulforaphane.The equilibrium experimental data obtained at different temperatures were well fitted to the Langmuir and Freundlich isotherms.It can be seen that the correlation coefficients(R²)of both the Langmuir and the Freundlich equations on SP850 resin were＞0.9300.To optimize the separation process,dynamic adsorption and desorption tests were performed with a column packed with SP850 resin.The results showed that the optimum parameters for adsorption were as follows:flow rate:5BV/h,pH 2,temperature:25℃; for desorption:ethanol-water(40:60,v/v),6 BV as an eluent,flow rate: 6BV/h.The highest purity of sulforaphane product was 85.9%,i.e., 107-fold higher than those in broccoli seeds through one run treatment on the column packed with SP850 resin under normal conditions.This indicated the high efficiency of SP850 resin in separating sulforaphane.The separation of active compounds from natural sources may encounter various problems,such as the compound of interest is of present only as a minor component in an extremely complex mixture. High-speed counter-current chromatography(HSCCC)was used for isolation and purification of sulforaphane from Broccoli seeds.The two phase solvent system of HSCCC composed of hexane- ethyl acetate -methanol-water(1:5:1:5,v/v),which has been selected by analytical HSCCC.Using preparative HSCCC,about a 982.1 mg amount of the crude extract(purity was 30.4%)was separated,yielding 286.6 mg of sulforaphane at a high purity of over 90%.In this paper,four separation methods(normal-phase low pressure liquid chromatography,preparation HLPC,macroporous resins and preparative HSCCC)have been compared by the purity,productivity and cost.We found that macroporous resins were an economical method for getting a medium purity.Furthermore,preparative HSCCC and preparation HLPC were the best choices for a high purity of over 90%.