Abstract: Five secondary metabolites were isolated from the ethyl acetate extract of the endophytic fungus Acremonium implicatum from tomato root galls infected with Meloidogyne incognita. They were identified as 4-hydroxy benzaldehyde (1),4-hydroxy benzoic acid (2),indole-3-carboxaldehyde (3),5′-O-acetylthymidine (4) and cerevisterol (5) by physicochemical properties and spectrometric methods. Compounds 1 and 2 showed strong antibacterial,antifungal,antioxidant and antinematodal activities. Compound 3 exhibited moderate antinematodal activity on Caenorhabditis elegans and M. incognita with the median inhibitory concentration (IC₅₀) values of 82.3 μg/mL and 93.4 μg/mL,respectively. The results indicated that 4-hydroxy benzaldehyde (1),4-hydroxy benzoic acid (2),and indole-3-carboxaldehyde (3) could be the main bioactive components in the endophytic fungus A. implicatum. The results will be helpful for clarifying biocontrol mechanisms of A. implicatum on the root-knot nematode as well as for development and utilization of this fungus. All the compounds were isolated from A. implicatum for the first time.

Key words: Lycopersicon esculentum, endophytic fungus, Acremonium implicatum, secondary metabolites, antimicrobial activity, antioxidant activity, antinematodal activity