Amino acid derivatives are a very broad family of ingredients with diverse functions. We have already dealt with some segments, such as biopeptides or lipoamino acids. Another family of particular interest are the glutamic acid derivatives, the “acetyl glutamates,” which are of great interest as the basis for various foam formulations. These are excellent surfactants. Virginie Herenton has taken great care of this in recent years, allowing us to travel through this universe. Thanks to her. Jean Claude Le Joliève
As the basis of fatty amino acid chemistry, acyl glutamates sparked real interest in rinse-off products in European cosmetics in the late 1990s. From a scientific point of view, these surfactants are considered mild multifunctional surfactants and are the best in the world. Hyperactive ingredients have many aspects and will remain very promising in the coming years.
Acyl glutamate is composed of one or more C8 fatty acids and L-glutamic acid and is produced by an acylation reaction.
Japanese researcher Kikunae Ikeda originally identified umami (delicious taste) as glutamate in 1908. He found that kelp soup contained some of these, as well as vegetables, meat, fish and fermented foods. He applied for a patent to industrialize a MSG seasoning called “Ajinomoto” and in 1908 collaborated with Japanese industrialist Suzuki Saburosuke to produce and market his invention. Since then, monosodium glutamate has been used as a flavor enhancer in foods.
The 1960s saw significant research into acyl glutamates as mild anionic surfactants. Class 1 acylglutamic acid was introduced by Ajinomoto in 1972 and was first used in dermatological cleansing bread by the Japanese pharmaceutical company Yamanouchi.
In Europe, cosmetics manufacturers became interested in this chemical in the mid-1990s. Beiersdorf worked extensively on MSG and was one of the first European groups to use it in their products. A new generation of hygiene products is born, with higher quality and greater respect for the structure of the epidermis.
In 1995, Z&S Group became the first raw material producer in Europe to produce acylglutamic acid at its Italian plant in Tricerro and continues to innovate in this area.
According to the Schotten-Bauman reaction, the neutralized form of acylglutamic acid is obtained by the reaction of fatty acid chlorides with glutamic acid after neutralization of the sodium salt with the sodium salt:
Industrial processes require solvents, so in addition to the salts remaining in the Schotten-Bowman reaction, reaction byproducts are also formed. The solvent used may be hexane, acetone, isopropyl alcohol, propylene glycol, or propylene glycol.
In the chemical industry there are various methods following the basic Bowman reaction: – Separation with mineral acids to remove salts and solvents followed by neutralization: the purity of the final product is high, but the process used requires several steps with high energy consumption. – Salts are retained at the end of the process and the solvent is distilled: this is a more environmentally friendly approach than previous methods, but requires additional steps for the main reaction – Salts and solvents are retained at the end of the industrial process; Process: This is the most sustainable one-step method. Therefore, the choice of solvent is critical and, in the case of propylene glycol, can provide additional benefits of acylglutamic acid, such as hydration or increased solubility of the formulation.
While the purity of the resulting acylglutamic acid is critical, manufacturers say demand for cosmetic brands is growing due to environmentally friendly practices.
Another key point of this sustainable approach is the plant-based and renewable origin of the raw materials from which acylglutamic acids are composed. Fatty acids come from palm oil, RSPO (Roundtable on Sustainable Palm Oil) (where available) or coconut oil. Glutamic acid is obtained from the fermentation of beet molasses or wheat.
Glutamic acid and fatty acids are physiological components of skin and hair. Glutamic acid is an important amino acid for epidermal NMF (natural moisturizing factor), a precursor to PCA, and is also an important amino acid for proline and hydroxyproline (two essential amino acids in the synthesis of collagen and elastin). Keratin contains 15% glutamic acid.
Free fatty acids in the stratum corneum account for 25% of the total amount of epidermal lipids. They are essential for the skin’s barrier function.
During keratinization, the process of acquiring cuticle, a large number of enzymes from Odran bodies are stimulated into the extracellular environment. These enzymes can break down various substrates.
When acylterocarboxylic acid is applied to the skin, it is broken down by these enzymes to form two original components: fatty acids and glutamic acid.
This means that there will be no residue of surfactants usually associated with acylglutamic acids and acylaminoacids on the skin or hair. Thanks to the use of these surfactants, the skin and hair restore their physiological composition.
100% cell survival in the presence of sodium octanoyl glutamate. The same is true for longer fat chains.
For example, cholesterol is an intercellular lipid of the corneal layer and plays an important role in the barrier function of the skin. It should not be dissolved or only slightly dissolved by the surfactants included in the cleaning formula.
In general, sodium lauroyl glutamate and acyl glutamate, regardless of the fat chain, are not defatting agents. They remove an important component of the rash, but not the intercellular cementing lipids necessary for the aqueous maintenance of the stratum corneum. This is known as the selective scavenging ability of acyl glutamates.
Sodium cocoyl glutamate significantly improves the moisturizing effect of rinse-off products. It also reduces the adsorption of SLES (sodium laureth sulfate) to the skin and is a hydrophilic oil-in-water emulsifier that allows cold processing of the skin. Therefore, it can be used to rinse items instead of rinsing. The same applies to the lauroyl chain. These are the two fattest chains currently used in the cosmetic market.
The figure below summarizes the different activity properties of acylglutamic acid added to glutamic acid depending on the fatty chain chosen.
Using a sustainable and innovative approach, Z&S Group offers a wide range of acyl glutamates under the brand name “PROTELAN”.
Multi-functional and offering a multitude of benefits for skin and hair, they are cutting-edge and fully meet the expectations of the 21st century consumer, while making the developer’s life much easier! They allow you to rationally formulate rinses and rinses while adhering to the famous “less is more” principle: fewer ingredients, more benefits. They perfectly combine sustainable and responsible chemistry.
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Post time: Apr-23-2024