Flavonoid
Flavonoid[edit]
Flavonoids are a class of polyphenolic compounds found in many plants. They are known for their diverse beneficial biological activities in humans and are a significant part of the human diet.
Structure[edit]
Flavonoids are characterized by their 15-carbon skeleton, which consists of two phenyl rings (A and B) and a heterocyclic ring (C). This structure can be abbreviated as C6-C3-C6.
The basic structure of flavonoids can be modified in various ways, leading to different subclasses such as flavones, flavonols, isoflavones, and others.
Subclasses[edit]
Flavones[edit]
Flavones are characterized by a double bond between C2 and C3 and a ketone at C4. They are commonly found in parsley, celery, and chamomile.
Flavonols[edit]
Flavonols have a hydroxyl group at C3 in addition to the structure of flavones. They are abundant in onions, kale, and broccoli.
Isoflavones[edit]
Isoflavones have a different arrangement of the B ring, which is attached at C3 of the C ring. They are primarily found in soybeans and other legumes.
Flavanones[edit]
Flavanones are similar to flavones but lack the double bond between C2 and C3. They are found in citrus fruits like oranges and grapefruits.
Anthocyanins[edit]
Anthocyanins are pigments responsible for the red, purple, and blue colors in many fruits and vegetables. They are water-soluble and found in berries, grapes, and red cabbage.
Chalcones[edit]
Chalcones are open-chain flavonoids that serve as precursors to other flavonoid classes. They are found in licorice and hops.
Biological Functions[edit]
Flavonoids are known for their antioxidant properties, which help in neutralizing free radicals and reducing oxidative stress. They also exhibit anti-inflammatory, antiviral, and anticancer activities.
Flavonoids can modulate cell signaling pathways and influence the activity of various enzymes. They are also involved in the regulation of gene expression.
Dietary Sources[edit]
Flavonoids are widely distributed in the plant kingdom and are present in a variety of foods and beverages. Common sources include:
- Fruits: apples, berries, grapes
- Vegetables: onions, kale, broccoli
- Beverages: tea, red wine, citrus juices
