Phytoalexin

Phytoalexins are a chemically diverse group of low-molecular-weight antimicrobial compounds produced de novo by plants in response to biotic and abiotic stresses, such as fungal or bacterial infections, UV radiation, or heavy metal exposure (Wikipedia, 2024; PubMed, 27552545). They serve as a critical component of the plant's innate immune system, accumulating at the site of infection to inhibit the growth of the invading pathogen. Common examples include resveratrol from grapes, camalexin from Arabidopsis, and glyceollin from soybeans (ScienceDirect, 2022). While they are of significant interest in human medicine for their antioxidant, anti-inflammatory, and anti-cancer properties, phytoalexins themselves are metabolites rather than therapeutic targets such as receptors or enzymes. Therefore, in the context of drug discovery, they are typically viewed as lead compounds or nutraceuticals rather than biological targets.

Other names

Plant antimicrobial compoundsStress-induced metabolitesPost-infectional inhibitory compounds

Phytoalexins function primarily through the direct disruption of pathogen cell membranes, inhibition of pathogen enzymes, and interference with fungal or bacterial metabolic processes (ScienceDirect, 2023). In human therapeutic contexts, specific phytoalexins like resveratrol act by modulating host pathways, such as the activation of SIRT1 or the Nrf2 signaling pathway, to provide antioxidant and anti-inflammatory effects (PubMed, PMC6164842).