Bistetrahydrofuran lignans isolated from Artemisia lavandulaefolia DC and their antifungal activities

In order to discover novel botanical fungicides, the chemical constituents of the aerial parts of Artemisia lavandulaefolia DC. were investigated. The aerial parts were extracted with methanol. By using liquid-liquid extraction, column chromatography, high performance preparative liquid chromatography and other techniques, 6 pure compounds were finally isolated from the ethyl acetate phase. The compounds were identified as bistetrahydrofuran lignans, including epiashchantin ( 1 ), ashantin ( 2 ), sesartemin ( 3 ), epimagnolin A ( 4 ), epiyangambin ( 5 ) and diayangambin ( 6 ), according to NMR and MS data. The mycelium growth rate method was used to determine the antifungal activities. The results showed that compound 1 and 3 significantly inhibited the growth of Alternaria solani with the EC₅₀ value of 14.3 μg/mL and 11.0 μg/mL, respectively. Compound 3 , 5 and 6 also showed inhibitory effect against the mycelia growth of Rhizoctonia solani with the EC₅₀ value of 17.4, 42.6 and 54.3 μg/mL, respectively.