| Kohlrabi is cruciferous family and biennial herb.It is also a commonly eaten vegetable.At present the research on Kohlrabi has focus on agriculture,there is few report on separation,purification,and composition.The extract from Kohlrabi poses many bioactivities including antitumor,antibiosis,antioxidant,hypoglycemic,and hypolipidemic.But because the activity ingredient has not been tracked and isolated,what are activity substances,which are not known.To better to understand,utilize,and development Kohlrabi,chemical substances in Kohlrabi were analyzed,isolated,and purification.Their structures were identified.Their antitumor activities were investigated.Main research contents of the research and conclusion are as follows.1.The extract conditions were optimized.The influence of extract conditions on extraction efficiency has been evaluated using single factor experiment and orthogonal experiment.The experiment result shown that solvent type had the most impact on extraction efficiency.Higher extraction efficiency could be gotten when methanol was used as extraction solvent.According to the orthogonal experiment result,the sequence decreasingly were the number of extract,solid-liquid ratio,extract time,and extract temperature.The optimum extraction conditions were that methanol was used as solvent,the extract temperature was 50?,the liquid-solid ratio was 1:35,the extraction time was 3h,and the number of extract was two times.Under the optimized process conditions,the extraction rate was 44.6%.2.The chemical composition in n-butanol extract from Kohlrabi methanol extract was analyzed using UPLC-ESI-Q-TOF-MS method.19 compounds,including glycoside,coumarins,terpenes,alkaloids,organic acid,and amino acids,were identified on the basis of the results from the chromatograph dates and mass spectrometric dates.3.The methanol extraction from kohlrabi was separated and purified.The petroleum ether extract,ethyl acetate extract,n-butanol extract,and water extract were obtained after water soluble substance of the Kohlrabi methanol extraction were extracted with petroleum ether,ethyl acetate,and n-butanol in sequence.Fourteen compounds were obtained from ethyl acetate extract and n-butanol extract with a combination of silica gel column,Sephadex LH-20 gel column,recrystallization,and semi-preparative high performance liquid chromatography.7 compounds were identified by means of infrared spectroscopy,nuclear magnetic resonance spectrometer,and mass spectrograph.They are: ?-sitosterol,tridecanoic acid,coumarin,3,4-dihydroxy benzoic acid,methyl 3,4-dihydroxybenzoate,and ?-daucosterol.4.The antitumor activity tests were carried out on the four solvent extracts from Kohlrabi methanol extract and the compounds obtained from them.Petroleum ether extract,ethyl acetate extract,n-butyl alcohol extract,and water extract from Kohlrabi methanol extract,and the compounds obtained from them were selected as the object of this study.HCT-116 and M-29 colorectal cancer cell lines and H-460 lung cancer cell line were chosen to be recipient cell.Antitumor activities of samples were evaluated using MTT method.The experiment results indicated that the antitumor activity of petroleum ether extract was the best in four extraction phases.The antitumor activity of water extract is better,and the antitumor activity of n-butyl alcohol extract is worst.The petroleum ether extract exhibited a higher antitumor activity in a concentration-dependent manner within the concentration range tested.The IC50 values of petroleum ether extract on H-460,M-29,and HCT-116 tumor cells were 48.50?g/mL,65.94?g/mL,and 143.68?g/mL,respectively.At concentrations of 50?g/mL,the proliferation inhibition rate of the compounds 1,2,9,and 10 on HCT-116 were 44.22%,34.28%,18.88%,and 5.40%,respectively.The proliferation inhibition rate of the compounds 1,2,9,and 10 on H-460 were 34.91%,49.65%,31.94%,and 49.55%,respectively.The results indicated these compounds have lower antitumor activity. |
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