Study On The Secondary Metabolites Of Aspergillus Sp. Isolated From Chinese Eaglewood

The black resin of Aquilaria sinensis is called Chinese agarwood which is a famous traditional medicinal material, and is used as rare senior spices or crafts.But A. sinensis is the national secondary protected plant on the brink of extinction, and is difficult to fulfil the daily increased market demand.Phytochemical studies on the the A. sinensis, Chinese agarwood and the endophytic fungus of Aquilaria sinensi have previously led to the isolation of a series of compounds, and some of which possessed antitumor and anti-inflammatory activities. In an effort to search for bioactive compounds, chemical constituents and bioactivities of Chinese agarwood endophytic fungi were studied. Fourteen compounds were isolated from the broth of endophytic fungus Aspergillus sp. by column chromatography, and their structures were elucidated by physicochemical and spectral data (UV, IR, MS,1D and2D NMR) as (2-hydroxy-3-pentanone)-2-fromyl-4-dimethylresorcinol (1),3-0-(α-D-ribofuranosyl)-teloschistin (2),1-O-methylemdin (3), teloschistin (4), neoechinulin A(5), neoechinulin B (6), cryptoechinuline C (7), cyclo-(Val-Trp)(8), cyclo-(Trp-Ala)(9), preechinulin (10), rhamnolipid2(11), dihydropenicillic acid (12), penicillic acid (13),6-methoxy-5(6)dihydropenicillic acid (14). Among them, compound1and2were new compounds.The antimicrobial activities of all the compounds were measured using paper disco diffusion method. Compound13exhibited anti-microbial activities against Staphylococcus aureus and Ralstonia solanacearum.In addition, antimicrobial activities of ethanol extracts from the52species of tropical medicinal plants (Leucas aspera, Croton laevigatus, etc.) were assayed by determined their inhibitory zone and minimal inhibitory concentration (MIC) sterilization against Ralstonia solanacearum in vitro. The results indicated that the ethanol extracts of13species showed antimicrobial activities. Atalantia buxifolia, Clerodendrum inerme and Croton laevigatus showed strong activity with the diameter of the inhibition zone of10.0,8.7, and12.0mm in the extracts with concentration of100mg/mL, and the MIC at3.13,6.25and6.25mg/mL, respectively. The13species plants are potential resources to find valuable bioactive components to control the Tobacco bacterial wilt, which are worthy of further study.