Isolation of Antioxidant Compound from Endophytic Fungi Acremonium sp. from the Twigs of Kandis Gajah

The endophytic fungi Chrisonilia sitophila, Acremonium sp., and Penicillium sp. have been isolated from the tissues of the twigs of kandis gajah. The fungal strains were grown in 3 l potato dextrose broth medium (PDB) at room temperature for 28 days. To extract the antioxidant compounds, the cultures broth were filtered for mycelia removal followed by extraction and evaporation. All of the extracts were evaluated for their antioxidant activities by using 1,1- diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity. The extract of Acremonium sp. had strong activity with IC50 value of 10.3 μg/ml, which is equivalent to ascorbic acid activity with IC50 value of 9.8 μg/ml. The extract was subjected to column chromatography on Si gel twice to obtain a high purity antioxidant compound in the form of yellow oil. The molecular structure was determined based on spectroscopic data, including 1H-NMR, 13C-NMR, HMQC, HMBC, and COSY. The compound was determined as sesquiterpene 3,5-dihydroxy-2,5-dimethyltrideca-2,9,11-triene- 4,8-dione.