Endophytic Aspergillus terreus was isolated from leaf of plant Ocimum basilicum L. Secondary metabolites were purified using chromatographic techniques HPLC, Preparative HPLC and mass was determined by LCMS. Through spectroscopic investigation and NMR, the structure was clarified. The chemical name of the synthesized compoundwas Butyrolactone (C₂₄H₂₄O₈) and the [M+H+] was observed as 441.15 that shows the molecular mass of the compound is 440.15amu. Bacillus subtilis, Staphylococcusaureus, Salmonella typhi, and Pseudomonas aeruginosa were tested for butyrolactone's in vitro antibacterial activity, whereas Candida albicans, Microsporum canis, Aspergillus flavus, and Alternaria solani were tested for butyrolactone's antifungal activity. At a maximal concentration of 1000μg/ml of the sample, the chemical Butyrolactone exhibited moderate inhibition against B. subtilis (60 ± 3.12%). Antifungal activity showed Butyrolactone remained inactive against test fungi. However, weak activity was observed against C. albicans (17 ± 2.08%) and A. flavus (12 ± 1.18%) at 1000 μg/ml concentration of the compound. From the results it is concluded that plant possess A. terreus contains Butyrolactone that is rich source of secondary metabolites with interesting antibacterial potential.

Index Terms- Antibacterial, Butyrolactone, Aspergillus terreus, Ocimum basilicum, secondary metabolites, antifungal