Identification and Quantification of a Phytotoxic Metabolite from .

is the causal agent of leaf blight (ALB) in carrot () crops around the world. However, to date, has received limited attention in its production of phytotoxic metabolites. In this investigation, the bioassay-guided isolation of the extract from liquid cultures of resulted in the isolation of two metabolites identified as -acetylorcinol () and -hydroxybenzoic acid (), based on their spectroscopic data and results from chemical correlation reactions. Testing of both metabolites in different assays showed an important phytotoxic activity for -hydroxybenzoic acid () when tested in the leaf-spot assay on parsley (), in the leaf infiltration assay on tobacco () and marigold (), and in the immersion assay on parsley and parsnip () leaves. Quantification of the two metabolites in the crude extract of kept at different times showed that -hydroxybenzoic acid () is one of the first metabolites to be synthesized by the pathogen, suggesting that this salicylic acid derivative could play an important role in the pathogenicity of the fungus.