Phenolic Compounds are a large group of secondary metabolites in plants characterized by at least one aromatic ring bearing one or more hydroxyl groups (-OH). They play crucial roles in plant defense, growth regulation, and human health.
Key Features
- Contain a benzene ring + hydroxyl group(s).
- Can be simple (phenolic acids) or complex (tannins, flavonoids, lignin).
- Widely distributed in leaves, fruits, seeds, bark, and roots.
Major Classes & Examples
- Phenolic acids – caffeic acid, ferulic acid.
- Flavonoids – quercetin, kaempferol, anthocyanins (pigments in flowers/fruits).
- Tannins – defense compounds, astringency in tea and wine.
- Lignin – structural polymer in plant cell walls.
- Coumarins – anticoagulant and antimicrobial compounds.
Biological Roles in Plants
- Defense: Antimicrobial, antifungal, insect deterrent.
- UV Protection: Flavonoids absorb harmful UV rays.
- Structural Integrity: Lignin strengthens vascular tissue.
- Attraction: Pigments aid in pollination and seed dispersal.
Health Benefits for Humans
- Antioxidant: Neutralize free radicals (ROS).
- Anti-inflammatory: Reduce risk of chronic diseases.
- Cardioprotective: Lower risk of heart disease.
- Anticancer: Some phenolics inhibit tumor growth.
- Neuroprotective: Linked to brain health.