微生物および生化学技術ジャーナル

概要

Isolation of Antioxidant Compounds from Aspergillus Terreus LS01

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.