Tomato (Solanum lycopersicum L.) has a source for bioactive phytochemicals. Alternaria cerealis is a pathogen that causes disease on variety of plant parts. This study amid to obtained novel secondary metabolites including phytoalexin compounds in tomato plant, following infection with Alternaria cerealis MT808477. Identification of the bioactive components present in leaves methanolic extracts was performed using gas chromatography mass spectrometry (GC-MS). Coumarin, tioconazole, octadecane, 9-ethyl-9-heptyl and fluticasone propionate were recorded. In addition, the detoxification of phytoalexin quinolizine, isoquinolizine and quinoline derivatives were also detected. Most of these compounds are candidate for valuable applications as antimicrobial, anti-inflammatory, antitumor agents and others.