Antioxidant activities of butyrolactones from marine endophytic fungus aspergillus terreus

Abstract

Marine organisms, particularly marine invertebrates, have proved to be a rich source of pharmaceutically active metabolites, some of which are under clinical trials. A fungal strain Aspergillus terreus isolated from red alga, Laurencia ceylanica was cultivated in bulk for 14 days and extracted with EtOAc. Above extract was purified using chromatography with Hexane/EtOAc mixtures as eluents to isolate butyrolactone-1 and butyrolactone-2. The positive CIMS of butyrolactone-1 showed its molecular ion peak at m/z 385.0 corresponding to [M + H],+ while the positive FAB MS of butyrolactone-2 showed the molecular ion peaks at m/z 425.0 corresponding to [M + H]+. Antioxidants are molecules which can safely interact with free radicals and terminate the chain reaction before vital molecules are damaged. An imbalance between antioxidants and reactive oxygen species results in oxidative stress, leading to cellular damage. In our studies, butyrolactone-1 and 2 were found to be significant radical scavenging potential against DPPH having the IC50 value of 88.2 ± 0.30 and 132.0 ± 3.77 M respectively. Propyl gallate (IC50 = 30.0 ± 0.27µM), was used as a standard antioxidant in the assay.