Flavonoids

Flavonoids are plant metabolites that are hypothesised to have health advantages via cell signalling pathways and antioxidant properties. These compounds can be found in many fruits and vegetables.

Flavonoids are polyphenolic compounds with 15 carbon atoms that are water-soluble. They are made up of two benzene rings linked by a three-carbon chain. One of the carbons in this chain is linked to carbon in one of the benzine rings, either indirectly or directly, resulting in a third middle ring. Flavonoids are classified into six major subtypes: chalcones, flavones, isoflavonoids, flavanones, anthoxanthins, and anthocyanins. Many of these compounds, particularly anthoxanthins, contribute to the yellow hue of some petals, whereas anthocyanins are frequently present.

Synthesis of Flavonoids

Flavonoids are synthesised by the phenylpropanoid route, which converts phenylalanine into 4-coumaroyl-CoA, which then enters the flavonoid biosynthesis pathway. Chalcone synthase, the initial flavonoid pathway enzyme, generates chalcone scaffolds from which all flavonoids are derived.

Functions of Flavonoids

Flavonoids are structurally diverse secondary metabolites found in plants that serve a variety of functions. These range from plant development, pigmentation, and UV protection functions to a variety of roles in defence and signalling between plants and microorganisms.

The process by which plants convert carbon dioxide, water, and sunlight into oxygen and energy in the form of sugar is known as photosynthesis. Autotrophic plants produce their own food through a process called photosynthesis. Sunlight, chlorophyll, CO₂, and water are four crucial components needed for this process. The two steps of photosynthesis are the Light Reaction and the Dark Reaction.

• Light reaction: The initial stage of photosynthesis is the light reaction, in which solar energy is transformed into chemical energy in the form of ATP and NADPH. Protein complexes and pigment molecules both contribute to the synthesis of NADPH and ATP.
• Dark reaction: The dark reaction is also known as the carbon-fixing process. It is a light-independent mechanism that produces sugar molecules from carbon dioxide and water molecules. The dark reaction takes place in the stroma of the chloroplast, where the products of the light reaction are used.