Chinese Gallnut Extract Ellagic acid 40%,90%

Ellagic acid (EA), also known as and gallic acid, is a plant polyphenolic substances, molecular formula for C14H16O18, is a dimeric derivative of gallic acid, widely found in various types of fruits and nuts, such as raspberries, pomegranates, strawberries, walnuts, lingonberries, the natural EA is mostly in the form of condensation (such as ellagic acid tannins / glycosides, etc.) in the nature, in addition, also in the free form in the fruit of many plants, it can be produced on a large scale through the hydrolysis of tannins. The natural EA exists mostly in condensed form (e.g. ellagitannins/glycosides, etc.) in nature, in addition, it also exists in the free form in the fruits of many plants, and its large-scale production can be achieved through the hydrolysis of tannins.

Ellagic acid has been included in the International Standard Catalogue of Cosmetic Ingredients (ISCI), and there are currently no restrictions on its use in cosmetics in the European Union, the United States of America and Japan. In Taiwan, China, ellagic acid is a whitening ingredient that has been published and approved by the competent authorities, and the limit for ellagic acid in cosmetics is set at 0.5 per cent (mass fraction).

Effects of Ellagic acid  :

1.Inhibition of tyrosinase activity

Tyrosinase monophenolase hydroxylates tyrosine to produce o-dihydroxyphenylalanine ( L- DOPA), and diphenolase oxidises L-DOPA to dopaquinone, which tends to multimerise and interacts with intracellular proteins to produce black or brown pigmentation. The type of inhibition can be divided into irreversible and reversible inhibition in terms of how tightly the inhibitor binds to the functional groups in the enzyme protein. Reversible inhibition can be classified as competitive, non-competitive and mixed inhibition according to its mechanism of action. And the inhibition of tyrosinase by ellagic acid belongs to the reversible process, i.e., by inhibiting the activity of tyrosinase rather than by reducing the amount of effective enzyme leading to a decrease in catalytic efficiency. Ellagic acid belongs to the mixed type of inhibition, which binds not only to the active centre of tyrosinase but also to other groups.

2.Anti-oxidant

Since phenolic antioxidants scavenge alkoxyl radicals mainly through the hydrogen abstraction reaction to produce more stable phenoxyl radicals to terminate the chain reaction, the stability of the resulting phenoxyl radicals is closely related to their radical scavenging activity. The more stable the phenoxy radical is, the stronger the radical scavenging activity is.

Ellagic acid has a catechol-type phenolic hydroxyl group, which, upon hydrogen abstraction, forms an intramolecular hydrogen bond with another phenolic hydroxyl group, resulting in an o-benzoquinone resonance structure that can stabilise the phenoxy radical. In addition, ellagic acid can prevent the production of free radicals through complexation with metal ions. The chemical properties of ellagic acid give it the ability to quench lipid radicals, thus interrupting the chain reaction of lipid oxidation and exhibiting strong antioxidant activity.

3.Astringent and antibacterial effects

The ability of plant polyphenols to bind to proteins is called astringency, and this reaction is an important chemical feature of plant polyphenols, which can also react with alkaloids, polysaccharides and even with biological macromolecules such as nucleic acids and cell membranes in a complex reaction similar to the tannin-protein binding. The astringent property makes cosmetics containing ellagic acid have good adherence to the skin under waterproof conditions, and allows large pores to shrink, makes loose skin taut and thus reduces wrinkles, and prevents the skin from secreting too much oil. In addition to being used in skin care products, ellagic acid can also be used as a perspirant, reducing sweat secretion by astringing the sweat glands; or added to hair products, using its astringent effect to prevent scalp oiliness, hair loss and dandruff.

L'Oréal has applied for a patent for a compound containing ellagic acid as an anti-dandruff agent, and experiments have found that the use of ellagic acid added at 0.5 per cent is effective in reducing M. marcescens compared to a control group, leading to a reduction in dandruff in patients.