Phlorotannin

Phlorotannin is a type of tannin found in brown algae. It is a complex polyphenol that is unique to marine environments, and is not found in terrestrial plants. Phlorotannins are responsible for the brown color of many types of algae, and they play a crucial role in the algae's defense against herbivores and pathogens.

Structure and Classification

Phlorotannins are polymers of phloroglucinol units, which are simple phenolic compounds. They can be classified into four main groups based on their structural characteristics: fuhalols and phlorethols, fucols, fucophlorethols, and eckols. The complexity and size of phlorotannin molecules can vary greatly, with molecular weights ranging from 126 to over 650,000 Da.

Biosynthesis

The biosynthesis of phlorotannins in brown algae is not fully understood. It is believed to involve the polyketide pathway, which is also responsible for the production of many other types of polyphenols in plants. The enzyme polyphenol oxidase is thought to play a key role in the polymerization of phloroglucinol units into phlorotannins.

Functions

Phlorotannins serve several important functions in brown algae. They provide protection against UV radiation, and they have antioxidant, antibacterial, and antifungal properties. They also deter herbivores by making the algae less palatable. In addition, phlorotannins can bind to proteins and other organic compounds, which can affect the availability of nutrients in marine ecosystems.

Uses

Phlorotannins have potential uses in various industries due to their antioxidant, antibacterial, and antifungal properties. They are being investigated for use in cosmetics, food preservation, and medicine. For example, they could be used to develop new types of sunscreen, to extend the shelf life of food products, or to treat infections and diseases.

See Also

• Tannin
• Algae
• Polyphenol
• Polyketide

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