Constituents And Antibacterial Activities Of Petroleum Ether Fractions Of Extarcts From The Barks Of Pseudostreblus Indica And Antioxidant Activity Of Leaves Of Pseudostreblus Indica

Pseudostreblus indica,a member of Streblus Lour.,belongs to Moraceae,mainly distributes in Gangdong,Hainan,Guangxi(south)and Yunnan(south)provinces,China.Pseudostreblus indica is often born in mountain forest or humid regions at an altitude of 650-1400 meters.Its medicinal part is the bark.It has many medicinal properties.It can treat gastrointestinal bleeding,stomach pain,traumatic bleeding,bruises,rheumatism and it can alleviate pain.There have been few reported researches about Pseudostreblus indica,and there has none researches about the constituents and pharmacological activities of the barks of Pseudostreblus indica.So the constituents and antibacterial activities of petroleum ether fractions of 75%ethanol extarcts from the barks of Pseudostreblus indica,and the antioxidant activity of leaves of Pseudostreblus indica were studied.In the dissertation,the petroleum ether fractions of 75%ethanol extarcts from the barks of Pseudostreblus indica was isolated by silica gel column chromatography,Sephadex LH-20,recrystallization,silica gel preparative TLC separation method accompanied with using analytical and preparative high performance liquid chromatograph(HPLC).The dried and powdered barks of Pseudostreblus indica was extracted by 75%ethanol.The extract was partitioned successively with petrol ether,chloroform,ethyl acetate,n-butyl alcohol and water,respectively.The petrol ether extracts(115 g)was subjected to silica gel CC to give 9 fractions:Fr.1,Fr.2,Fr.3,Fr.4,Fr.5,Fr.6,Fr.7,Fr.8 and Fr.9.During the purification process,22 compounds were isolated,and 18 of them were identified by spectrometric data of 1D NMR(1H-NMR,13C-NMR),2D NMR(COSY,HMBC,HMQC),IR,UV,MS,XRD(single-crystal X-ray diffraction),and by comparison with literature values.They were:bergapten(1),4-[3-(4,5-dihydro-5,5-dimethyl-4-oxo-2-furanyl)-butoxy]-7H-furo[3,2-g][1]benzopyran-7-one(2),bergapten dimer(3),marmesin(4),braylin(5),seselin(6),umbelliferone(7),herniarin(8),scopolin(9),6-aldehydo-7-hydroxy-5-methoxycoumarin(10),scoparone(11),2,2’-oxybis(1,4-di-tert-butylbenzene)(12),epibetulinic acid(13),betulin(14),uvaol(15),α-amyrin acetate(16),erythodiol(17),dibutyl phthalate(18).Compounds 2,3,4,5,6,8,10,11,12,13,14,15,16,17,18 was isolated from the plant for the first time by searching data-base of SciFinder Scholar.Antibacterial activity assay tested four compounds:marmesin(4),seselin(6),scopolin(9),epibetulinic acid(13).Using Aspergillus niger,Saccharomyces cerevisiae,Escherichia coli,Bacillus subtilis,Staphylococcus aureus as tested strains,studied the antibacterial activities of these four compounds by the agar disk diffusion method and serial dilution method.These four compounds all showed antibacterial activities to a certain extent.The antioxidant activity of petroleum ether extract,trichloromethane extract,ethyl acetate extract,n-butanol extract and water extract from the leaves of Pseudostreblus indica were tested by DPPH method.The ethyl acetate extract and the part of dichloromethane:methanol(80:20)of the extract showed the best antioxidant activity on scavenging DPPH radical.In recent years,the whole world pay more and more attention on the development and application of natural medicine.Researching and developing the low toxicity and high efficacy of natural medicine can improve the international medical level.So the industry has the broad prospect.Pseudostreblus indica,which is a kind of Guangxi natural medicinal plant,has better pharmacological activity.So the dissertation take Pseudostreblus indica as research object.