Phytoalexins as Bioactive Compounds: Structural Diversity, Biosynthesis, and Pharmacological Profile

Phytoalexins are low-molecular-weight secondary metabolites with remarkable antibacterial activity, synthesized within the plants in response to abiotic and biotic stimuli. Their structural diversity enables interaction with multiple biological targets, positioning them as promising candidates for nutraceuticals and pharmaceutical research. Preclinical studies have reported antibacterial, anti-diabetic, neurological disorder, antioxidant, anti-inflammatory, and cardiovascular activities. Nonetheless, a few obstacles, including inadequate bioavailability, diversity among botanical sources, and insufficient clinical evidence, remain major challenges for therapeutic translation. Diverse innovative strategies in metabolic engineering, nanodelivery, and biotechnology may improve the synthesis, stability, and therapeutic efficacy of these molecules. Phytoalexins are promising natural molecules that link plant defense mechanisms to potential human health applications, although further clinical validation is required.