carotenoids, also known as tetraterpenoids, are a diverse group of fat-soluble pigments naturally occurring in plants, algae, and photosynthetic bacteria. they serve essential roles as precursors of vitamin a, antioxidants, and protective agents against photooxidative damage. carotenoids such as β-carotene, lutein, and zeaxanthin are vital for eye vision, skin health, and immune function.
chemical properties
molecular weight: approximately 536.87 g/mol (β-carotene)
density: 0.94 g/cm³ (β-carotene)
melting point: 180–183°C (β-carotene)
solubility: soluble in fats and organic solvents; insoluble in water
optical rotation: +448° to +461° (β-carotene, chloroform)
chemical formula: C₄₀H₅₆ (β-carotene)
usefulness in medicine
carotenoids, especially β-carotene, act as precursors to vitamin a, preventing and treating vitamin a deficiency and associated conditions such as night blindness.
lutein and zeaxanthin support eye health, significantly reducing the risk of age-related macular degeneration and cataracts.
due to their strong antioxidant properties, carotenoids protect cells from oxidative stress, reducing inflammation and potentially lowering risks of cardiovascular disease and certain types of cancer.
carotenoids also enhance the immune system, supporting effective immune responses and decreasing susceptibility to infections.
antibacterial and antimicrobial activity
carotenoids exhibit antimicrobial activity primarily through their antioxidant and immune-enhancing properties, strengthening natural defense mechanisms.
• bacteria: