Study On Preparation And Anti-Cancer Activity Of Sulforaphane

At present, sulforaphane 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 phase Ⅱ 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:analyzing the contents of sulforaphane in Cruciferous plants in our country; studying effects of different hydrolyzing conditions on the formation of sulforaphane; purifying sulforaphane from broccoli seeds by normal-phase and reverse-phase preparative liquid chromatography; studying effects of different conditions on the stability of sulforaphane in water.A novel HPLC method has been devised for analyzing the contents of sulforaphane in Cruciferous plants in our country. The method is easy and rapid, and can obtain satisfied separation results. It has been found that there are significant differences with the contents of sulforaphane in various species and even in different tissues from the same plant.The formation of sulforaphane can be inhibited by increasing the hydrolyzing temperature. The optimum pH for the formation of sulforaphane is7.2, and the acid or basic condition will bring the inhibiting action. EDTA has no effect on the formation of sulforaphane. Zn2+can increase the yield of sulforaphane, but Cu2+, Fe2+, Fe3+, and Ca2+and Mg2+inhibit the formation of sulforaphane. It is beneficial to the sulforaphane formation when adding vitamin C into the hydrolyzing system.Sulforaphane has been separated and purified by solid phase extraction (SPE) and preparation HLPC. Compared with traditional liquid-liquid extraction, higher content and recovery of sulforaphane can be acquired by SPE. Moreover, the consumption of solvents by SPE significantly decreased. Separative conditions for preparative separation were groped by analytical HPLC, and30%methanol in water as the mobile phase, room-temperature (not higher than30℃), and neutral pH were chosen. The optimum parameters when using preparative HLPC are27.5%methanol in water as the mobile phase and12ml/min of the flow-rate. The highest purity of sulforaphane was99%at the condition of20mg loading-amount, and the purity decreased with the increase of loading amount. In addition, for raising production ability, preparative HLPC can be operated at the over-loading condition, and heart-cutting should be used for improving the purity of sulforaphane.Sulforaphane has also been separated and purified by normal-phase low pressure liquid chromatography. The mobile phase of normal-phase low pressure liquid chromatography was chosen by silica gel thin layer chromatography. When using hexane:ethanol (5:5, V/V) as the developing reagent, sulforaphane can be separated from other impurities completely. The crude sulforaphane extracts were purified by normal-phase low pressure liquid chromatography with different eluents and elution modes. When using the gradient elution mode, the loading amount less than0.5g, and the flow-rate at10ml/min, the highest purity of sulforaphane can be obtained.Inhibitory effects of sulforaphane on human lung adenocarcinoma A2cells in vitro and in vivo were studied. The half inhibition concentration (IC50) was6.25μmol when A2cells were treated for24h. The inhibition of sulforaphane can be strengthened when increasing the treating time or the concentration of sulforaphane. Sulforaphane can significantly induce S arrest and apoptosis in human lung adenocarcinoma A2cells. Moreover, the weight of xenogenic transplant tumor of lung adenocarcinoma A2cells in nude mice can be decreased about50%with50-75mg/kg sulforaphane I.P. injection. Therefore, sulforaphane is a promising molecule for fighting cancer. At the condition of high temperature (>50℃), sulforaphane in water is unstable. Sulforaphane is stable in the condition of pH3.0, and is easy to be decomposed by basic reagents. In addition, sulforaphane can not be decomposed and is stable in the condition of light.