Chemical Components From Pseudolarix Kaempferi Seek And Their Antibacterial Activity

The Pseudolarix kaempferi Gord distributing in the south China,is the endemic plant of China.And it has been widely used in China for treatment of skin diseases caused by fungal infections as a traditional Chinese medicine.A series of characteristic compounds isolated from this plant have been reported to have antifungal and antitumor activities,which is the research hotspot of phytochemistry currently.In this thesis,the chemical constitutes of the seek of Pseudolarix kaempferi Gord.were studied,11 compounds were isolated and their structures were elucidated by means of physicochemical properties and spectral analysis,they were pseudolarolide U(1*),25S-(1R,4),(16R,23S)-diepoxy-9?,10?-epidioxy-3(4),9(10)-disecocycloartan-26(23)-olide-3-butyl ester(2*),pseudolarolide I(3),25R-16 R,23S-epoxy-9?,10?-epidioxy-3(4),9(10)-disecocycloartan-l-en-3(4),26(23)-diolide(4),pseudolarolide E(5),3-oxo-16 S,23-epoxycycloartan-24-en-26(23R)-olid,25R-9S-hydroxy-1(9),16R(23S)-diepoxy-3(4),8(9),9(10)trisecocyctoartan-1,10(19)-dien-3(4),26(23)-diolide(6),pseudolarolide B(7),pseudolarolide Q(8),pseudolarolide D(9),3-oxo-16 s,23epoxycycloartan-24-en-26,23s-olide(10),pseudolarolide A(11).The compounds(1*)and(2*)were identified as new compound.The further antibacterial activities of the chemical constituents were taken under detecting the minimum inhibitory concenatriton by microdilution method.The result showed some of the constituents had inhibition activities against Staphylococcus aureus,Escherichia coli and Bacillus subtilis in different degrees.Compound 8 have inhibition effect on these three bacteria(MIC,6.08,97.28,24.32 ?M),while compound 7 was obviously active against Escherichia coli(MIC,13.41 ?M).The isolated compounds can be used as potential prospective antibacterial compounds,which can be used as reference for the development of new antibacterial drugs.