Rizna Triana Dewi, Sanro Tachibana, Kazutaka Itoh and Muhammad Ilyas
The antioxidative activity of an ethyl acetate extract from Aspergillus terreus LS01was evaluated using various in vitro assays: 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydrogen-peroxide-scavenging free radical scavenging, and β-caroten-linoleat model assay and the antioxidants in the extract were isolated and identified. Silica gel column chromatography was used to separate the extract into five fractions (F1-F5). Fraction 3 possessed significant antioxidative activity with an IC 50 of 19.91μg/ml. Fraction 3 was further separated by column chromatography and yielded the crystalline compounds 1 and 2, which were identified as terreic acid and terremutin, respectively, on the basis of UV-vis spectra, MS and NMR analyses. Terreic acid and terremutin exhibited the highest level of DPPH free radical scavenging activity with IC 50 values of 0.115±4.02 and 0.114±2.19 mM, respectively. These compounds also showed scavenging activity of hydrogen peroxide radicals which terreic acid exhibited higher than terremutin with 74.07±1.48% and 33.74±2.81% respectively. In the β-caroten-linoleat model assay, the inhibition of terreic acid retained 26.01±1.14% and terremutin retained 32.29±2.23%. This is the first report on antioxidative activity of terreic acid and terremutin from A.terreus . The findings indicated that A. terreus could be considered as potential source of natural antioxidant products.