Studies On Antifungal Activity Of Bistetrahydrofuran Lignans From Artemisia Lavandulaefolia DC.

Artemisia lavandulaefolia DC.belongs to the Compositae,Subgen.Artiemisia.This kind of plant has medicinal activity,which is widely distributed in China and is rich in chemical components.This paper starts from the perspective of agricultural antifungal activity of the aerial parts of Artemisia lavandulaefolia DC.The chromatographic method,the spectroscopy method,the microdilution method and the mycelium growth rate method were used to study the bistetrahydrofuran lignans isolated from Artemisia lavandulaefolia DC.,and the following results were obtained:1.The chemical constituents from the aerial parts of Artemisia lavandulaefolia DC.were extracted with methanol.The methanol extract was extracted with ethyl acetate to get the ethyl acetate phase.The ethyl acetate phase was separated by the first silica gel column,we got 8 components(A-H)with the TLC method.The C component was determined for its antifungal activities against 5 tested pathogenic fungis such as Alternaria solani by the mycelium growth rate method.The results showed that this component had obvious antifungal activities against Alternaria solani?Rhizoctonia solani and Fusarium graminearum when the medium concentration is 2.5 mg/m L,and the inhibition rates were over 55%.2.6 pure compounds were finally obtained from the C component by using silica gel column chromatography,gel column chromatography,high performance liquid chromatography and other isolation techniques.Using spectral techniques and reference to the literature data,the compounds were identified as epiashchantin(1),ashantin(2),sesartemin(3),epimagnolin A(4),epiyangambin(5),diayangambin(6),they are all bistetrahydrofuran lignans.3.Compounds 1-6 were tested for their antifungal activities by microdilution method,we chose Alternaria solani,Rhizoctonia solani,Fusarium graminearum,Fusarium oxysporum and Pyricularia oryzae Cav for primary screening.The results showed that the inhibition rates of compound 1 and 3 on Alternaria solani were 72.28% and 81.45%,respectively;the inhibition rates of compound 3,5 and 6 on Rhizoctonia solani were 70.13%,68.37% and 65.08%,respectively.4.The mycelium growth rate method was used to determine the antifungal toxicity.The results showed that compound 1 and 3 significantly inhibited the growth of Alternaria solani with the EC50 value of 14.34 ?g/m L and 10.95 ?g/m L,respectively;compound 3,5 and 6 also showed inhibitory effect against the mycelia growth of Rhizoctonia solani with the EC50 value of 17.45 ?g/m L,42.59 ?g/m L and 54.30 ?g/m L,respectively.The structure-activity relationship indicates that the methylenedioxy structure on the benzene ring plays a key role in the antifungal activity of this kind of lignans.