What exactly is Phloretin Composed of?

In today's cosmetics and functional food ingredient market, Phloretin is undoubtedly a rising star. It is known as the "whitening gold" due to its excellent antioxidant, anti-inflammatory, and whitening potential, and is highly favored by formulators and consumers. What exactly is Phloretin composed of? "This is not only a simple chemical problem, but also related to the reliability of its source, the progressiveness of its production process, and the future market trend.

From a chemical structure perspective, Phloretin is not a complex molecule, but its unique structure endows it with strong biological activity. Phloretin belongs to a specific subclass of natural flavonoids - dihydrochalcones. Its core molecular skeleton is a classical C6-C3-C6 structure._[1]
It is worth noting that in nature, Phloretin often exists in its glycosidic form, Phlorizin. Phlorizin is a compound formed by connecting a glucose molecule to the hydroxyl group at the 2'-position of Phloritin. In plants, the storage form of Phloretin is more stable and common. However, during extraction or application, Phloretin with higher biological activity can only be obtained by hydrolysis and removal of the glucose group.

The commercial value of Phloretin begins with its natural source. It mainly exists in juicy fruits, especially in the fruit, skin, root bark, and leaves of apples (Malus domestica) and pears (Pyrus communis)._[1] Among them, apples are the most important commercially discovered natural source of Phloretin (and Phlorizin) to date. This not only explains why apple extract is so popular in skincare products, but also provides the raw material basis for the early production of Phloretin.
The primary reason plants synthesize these compounds is as a defense mechanism to resist ultraviolet radiation, pathogen invasion, and oxidative damage. It can be said that Phloretin is a "natural sunscreen" and "antibacterial agent" that plants have evolved over a long period of evolution to adapt to their environment.

At the cellular level, the biosynthesis pathway of Phloretin belongs to a branch of the flavonoid synthesis pathway._[2] The synthesis process can be summarized as the following key steps:
1. Formation of starting substrates: This pathway begins with phenylalanine and generates 4-coumaroyl-CoA through a series of reactions, which is a common precursor for the synthesis of many phenolic compounds.

2. Key reduction steps: Unlike the synthesis of other flavonoids such as naringenin, the synthesis pathway of Phloretin has a unique step. Under the catalysis of NADPH-dependent double bond reductase (DBR), the double bond on the C3 chain of 4-coumaroyl-CoA is reduced to form 4-dihydrocoumaroyl-CoA. This step is crucial in determining the direction of the product towards the dihydrochalcone structure.

3. Skeleton construction: Subsequently, under the catalysis of Chalcone Synthase (CHS), one molecule of 4-dihydrocoumaroyl CoA undergoes a condensation reaction with three molecules of malonyl CoA, ultimately cyclizing to form the C6-C3-C6 basic skeleton of Phloretin.

4. Glycosylation modification: In plants, synthesized Phloretin is further modified by glycosyltransferases, which combine with glucose to form Phloretin for storage and transportation.

After understanding the natural sources and biosynthetic pathways of Phloretin, we naturally pay attention to its industrial production methods. At present, there are two main technical routes for the production of Phloretin:

1. Traditional plant extraction:

This is the most classic method, which involves extracting and purifying plant materials rich in Phloretin (mainly by-products such as apple bark and apple pomace) using solvents. Although technically mature and naturally derived, this method faces challenges, including low yield, high purification costs, and sensitivity to seasonal and raw material variations.

2. Biological synthesis (synthetic biology):

With the rapid development of synthetic biology technology, using microorganisms as "cell factories" to produce Phloretin has become a research hotspot and future direction. Researchers have used genetic engineering techniques to transplant the entire enzymatic reaction pathway responsible for synthesizing root bark extract from plants (such as key enzymes DBR, CHS, etc.) into engineered yeast or Escherichia coli.

Returning to our initial question: 'What is Phloretin composed of?'? "The answer is multi-level:

• Chemically, it is a dihydrochalcone compound composed of two benzene rings and a three-carbon chain.
• In nature, it is a natural product synthesized by plants such as apples through photosynthesis and complex secondary metabolic pathways.
• Technically, it can be extracted from plants or efficiently and sustainably manufactured through modern biotechnology using microbial fermentation.

APPCHEM specializes in producing high-purity Phloretin for cosmetic and pharmaceutical applications. Our products are known for their exceptional quality, stability, and efficacy. Enhance your skincare and wellness formulations with Appchem's phloretin, backed by rigorous R&D and strict quality control. Explore more at AppChem! (Serrisha: cwj@appchem.cn; +86-138-0919-0407)

Reference
[1]L. Wang, Zheng Li et al. "Synthesis, Crystal Structure, and Biological Evaluation of a Series of Phloretin Derivatives." Molecules. [2014-10-01]
[2]Wei Lingzhen, et al. Research on the biosynthesis of flavonoids and their application in cosmetics.
[3]8. Phloretin: A Natural Dihydrochalcone with Promising Anti-Cancer Potential. Abkin SV. [2024-03-30]