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Macaranga tanarius, an important medicinal species, is widely distributed in several districts of our country. According to the literature. Macaranga tanarius has a therapeutic effect on malignant tumor, swelling and sores, glycuresis, cough, cuts, abrasions, nervous system, diarrhea and cardiovascular system. The effect of Macaranga tanarius extracts on antioxidative test, bacteriostatic experiment and antineoplastic experiment were studied in this paper in order to provide the scientific basis for the medicinal value of Macaranga tanarius.The ethyl alcohol-backflow extracting was used to extract Macaranga tanarius leaves. Therefore, the total ethanol, petroleum ether, ethyl acetate(EtOAc), n-butanol(n-BuOH) and water extracts of Macaranga tanarius leaves were extracted. The antioxidant activity of Macaranga tanarius extract was evaluated respectively. It included determination of polyphenol, DPPH-scavenging capacity, O2--scavenging effect, determination of reducing capacity and determination of flavonoid content. The bacteriostasis activities were tested by bactericidal test and minimum inhibitory concentration experiment(MIC), which were used to determine the size of circle of inhibition and MIC of the different extracts from Macaranga tanarius leaves. Anti-proliferative effects of different extracts from Macaranga tanarius leaves on colon cancer LOVO, MKN45, AGS, SK-HEP1and HEPG-2were observed by MTT method and screened out the effective part. The separations of monomeric chemical substances in ethyl acetate extraction part of Macaranga tanarius have been carried out through chromatographys.The antioxidant experiment results showed that the reduction capacity of n-butanol extract from Macaranga tanarius was strongest while the petroleum ether extract and aqueous extract had no obvious antioxidation. Macaranga tanarius extracts had DPPH and O2-scavenging effect to various degrees. With the extractions concentration increasing, the effects of scavenging and inhibiting were strengthened. And n-butanol extracts show the highest activity. The content of polyphenol and flavonoids is the highest in n-butanol extract. It provided scientific basis for searching effective and new-style natural preservative and antioxidant.It has been discovered that the different extracts from Macaranga tanarius leaves can suppress the growth of Staphylococcus aureus, Staphylococcus albus, Micrococcus luteus. Escherichia coli and Bacillus subtilis while the ethyl acetate(EtOAc) extracts of Macaranga tanarius leaves was most effective, and the MIC are0.2mg/mL,0.2mg/mL,0.3mg/mL,3.0mg/mL,1.5mg/mLBy MTT assay, the ethanol extract, petroleum ether extract and ethyl acetate extract of Macaranga tanarius leaves can obviously inhibit the growth of LOVO, MKN45,AGS, SK-HEP1and HEPG-2, and the IC50of ethanol extract of Macaranga tanarius leaves are0.460,0.082,0.210,0.201and0.371mg/mL, the IC50of petroleum ether extract are0.189,0.138,0.295,0.143and0.193mg/mL, the IC50of ethyl acetate extract are0.226,0.093,0.155,0.07,0.118mg/mL. The n-butanol extract of Macaranga tanarius leaves could inhibit the HEPG-2markedly of the IC50is0.245mg/mL but low inhibition on LOVO, MKN45of the IC50was1.110,2.584mg/mL respectively. The aqueous extract showed the postive antitumor action on MKN45of the IC50is0.264mg/mL, but negative antitumor action on other tumor cells.Experiments have demonstrated that ethyl acetate extract of Macaranga tanarius hold the best bacteriostasis and antineoplastic. Therefore, on this basis, active ingredients for antitumor would be isolated from the Macaranga tanarius leaves by followings biological effect to the tumor cells. The ethyl acetate extract was isolated and purified by the use of silica gel column chromatography, Sephadex LH-20column chromatography, pre-HPLC and so on. The structures of isolated compounds were identified through spectral analysis (1H-NMR、13C-NMR and IR) and physical-chemical properties. Two compounds were isolated and identified in the process. They were, respectively, gallic acid,6-hydroxy-8-methoxy coumarin and in which compound Ⅱ is obtained from the genus for the first time. The study will be probably benefit the knowledge of Macaranga tanarius. In addition, it can also supply the material base for activity of Macaranga tanarius and will be taken as the scientific basis for further study.
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