The key difference between flavonoids and polyphenols is that the flavonoids generally contains a 15-carbon skeleton whereas the polyphenols contain different carbon skeletons.
Flavonoids are a group of polyphenols. However, not all polyphenols are flavonoids. Moreover, flavonoids are naturally occurring compounds whereas polyphenols can be natural, semi-synthetic or synthetic.
CONTENTS
1. Overview and Key Difference
2. What are Flavonoids
3. What are Polyphenols
4. Side by Side Comparison – Flavonoids vs Polyphenols in Tabular Form
5. Summary
What are Flavonoids?
Flavonoids are a group of polyphenolic compounds. They are secondary metabolites of plant and fungus. When considering the chemical structure of flavonoids, they generally have a 15-carbon skeleton. There, it has two phenyl rings and a heterocyclic ring.
Figure 01: Basic Structure of Flavonoids
Consequently, we can name the structure as C6-C3-C6. There are three major classes of flavonoids as follows:
- Bioflavonoids
- Isoflavonoids
- Neoflavonoids
All the above structures are ketone containing compounds. When considering the function of these compounds in plants, its most useful function is that it acts as a plant pigment for flower colouration. There, it produces yellow, red or blue colouration. These colours exist on petals of a flower as a strategy to attract pollinator animals such as insects. Moreover, these compounds involved in UV filtration, nitrogen fixation, floral pigmentation, etc.
What are Polyphenols?
Polyphenols are large compounds containing more than one phenolic groups in their chemical structure. These compounds are either natural or synthetic. There are sometimes semi-synthetic forms as well. Often, these are very large compounds. Moreover, these compounds tend to deposit in cell vacuoles. The molecular weight of these compounds allows them to rapidly diffuse across cell membranes.
Further, these compounds have heteroatomic substituents other than hydroxyl groups. There, ether groups and ester groups are common. When considering the chemical properties of these molecules, they have UV/visible absorptivity, due to the presence of aromatic groups. Also, they have autofluorescence properties. Apart from that, they are very reactive towards oxidation.
Figure 02: Structure of Ellagic Acid – a Natural Phenol Antioxidant found in numerous Fruits and Vegetables
When considering the uses of these compounds, people traditionally used it as dyes. Moreover, there are some biological uses such as;
- The release of growth hormone in plants
- Suppression of growth hormone in plants
- Act as signalling molecules in ripening and other growth processes
- Provide prevention from microbial infections.
What is the Difference Between Flavonoids and Polyphenols?
Flavonoids are a group of polyphenolic compounds and polyphenols are large compounds containing more than one phenolic groups in their chemical structure. The key difference between flavonoids and polyphenols is that the flavonoids generally contains a 15-carbon skeleton whereas the polyphenols contain different carbon skeletons. Moreover, flavonoids are naturally occurring compounds while polyphenols can be natural, semi-synthetic or synthetic. So, this is another difference between flavonoids and polyphenols.
Summary – Flavonoids vs Polyphenols
All flavonoids are polyphenols, but not all polyphenols are flavonoids. Therefore, the key difference between flavonoids and polyphenols is that the flavonoids generally contains a 15-carbon skeleton whereas the polyphenols contain different carbon skeletons.