| Purslane (Portulaca oleracea L.) is a kind of traditional medicine edible wild plant in China.Purslane has a variety of bio-active and obvious effect.As a kind of bio-active substance,alkaloids are effective components of many natural plants.In this thesis,studied the extraction,purification,identification and the anti-tumor effect of the alkaloids from purslane. Therefore,it is great promising and significance to the study of alkaloids from Portulaca oleracea L.On the purslane chemical composition of pre-trial system, the system pre-test results show that it contains polysaccharides, flavonoids, alkaloid, protein, phenolic, saponins, organic acids, terpenes and other ingredients.Ultrasonic assisted extraction the alkaloids from purslane is an effective new measure,with the short time and low cost.Through single-factor experiments and response surface experimental,the optimal extraction parameters of alkaloids was established as below:ethanol concentration 95%,ratio of the material-liquid 1:10(g/mL), ultrasonic extraction time 15min,extraction time 1 hour,and the extraction rate 0.330 g/Kg increased 15 times than before.The extracting solution of alkaloid extracted by diethyl ether,and absorpted by AB-8 macroporous resin.The extracting of alkaloid volume was 100 mL,pH of sample-loading was 2, eluted with 80% ethanol 200mL.Then re-crystallization by ethanol.After kepting at 0-4℃,8-10h.Finally,the alkaloid turned into white needle crystal.Scaning by Uitra-violet Spectrum, there are two absorption peaks at 205nm and 273nm.Identified the alkaloid of purslane by Infrared Spectroscopy,HPLC and MS. The result showed it contains caffeine. But the components of alkaloids is complex, we still keep studying with other advanced measures.Studied the inhibition of alkaloids of purslane to BEL-7402 cell's proliferation by MTT assay.The effect is improved when the concentration and cultivation time increases.At 200μg/mL,the time was 4h,8h,24h of the inhibition rates were 33.74%,42.50%,50.09%. |
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