Moisturizing Mechanism of Polyglutamic Acid: From the γ-Glutamyl Structure to Hydration Networks and Surface Film-Forming Behavior
Moisturizing Mechanism of Polyglutamic Acid: From the γ-Glutamyl Structure to Hydration Networks and Surface Film-Forming Behavior
1 What Is Polyglutamic Acid?
1.1 Polyglutamic acid in skincare products usually refers to poly-γ-glutamic acid
The polyglutamic acid used in skincare products usually refers to poly-γ-glutamic acid, abbreviated as γ-PGA.
γ-PGA is a natural polymer composed of numerous linked glutamic acid units. Industrially, it is generally produced by microbial fermentation using Bacillus species and other microorganisms. Depending on the microbial strain and production conditions, γ-PGA may consist of D-glutamic acid, L-glutamic acid, or a combination of both, and its molecular weight may vary over a wide range.[1,3]
The sodium salt of γ-PGA, known as sodium polyglutamate, is also commonly used as a cosmetic ingredient. The sodium salt generally exhibits good dispersibility in water, but its actual viscosity, film-forming properties, and sensory characteristics still depend on its molecular weight, concentration, pH, and the electrolytes present in the formulation.
1.2 γ-PGA is a polyamino acid, but not a conventional protein
γ-PGA is indeed composed of amino acid units and can be classified as a polyamino acid or a natural polyamide. However, it differs substantially from conventional proteins such as collagen, keratin, and enzymes in terms of linkage type, monomer composition, structure, and function.
Comparison item | Poly-γ-glutamic acid | Conventional proteins |
Basic composition | Mainly composed of repeating glutamic acid units | Composed of multiple amino acids arranged in specific sequences |
Main linkage type | The α-amino group and γ-carboxyl group form γ-amide bonds | The α-amino group and α-carboxyl group form conventional α-peptide bonds |
Stereochemical composition | May contain both D- and L-glutamic acid | Natural proteins are mainly composed of L-amino acids |
Molecular structure | Predominantly a repetitive long-chain structure | Usually possess defined amino acid sequences and folded structures |
Basis of function | Carboxyl-group density, molecular weight, hydration, and interchain interactions | Amino acid sequence and specific three-dimensional conformation |
The functions of conventional proteins often depend on precise amino acid sequences and three-dimensional folding. By contrast, the moisturizing effects of γ-PGA arise primarily from the high density of carboxyl groups generated by its repetitive structure and from the physicochemical behavior of its polymer chains in water.
2 Why Are γ-Amide Bonds Essential for Understanding Polyglutamic Acid?
2.1 Glutamic acid contains two carboxyl groups
The basic structure of glutamic acid can be simplified as follows:
H₂N—CH(COOH)—CH₂—CH₂—COOH
It contains:
· one α-amino group;
· one α-carboxyl group;
· one γ-carboxyl group located at the end of the side chain.
When conventional proteins form peptide chains, the α-carboxyl group of one amino acid is generally linked to the α-amino group of another amino acid.
γ-PGA uses a different linkage pattern: the γ-carboxyl group of one glutamic acid unit forms an amide bond with the α-amino group of the next glutamic acid unit.
The linkage can be represented as follows:
γ-COOH ＋ H₂N-α → γ-CO—NH-α ＋ H₂O
Its repeating structure can be simplified as:
[—NH—CH(COOH)—CH₂—CH₂—CO—]ₙ
This structural formula is primarily intended to indicate the linkage positions between adjacent glutamic acid units. During microbial fermentation, the actual polymerization process is driven by a membrane-associated synthetase system; it is not a spontaneous condensation of free glutamic acid in an ordinary aqueous solution.[1,3]
2.2 The γ-linkage preserves a large number of lateral carboxyl groups
Because the γ-carboxyl group participates in formation of the polymer backbone, the α-carboxyl group of each repeating unit remains on the side of the polymer chain.
As a result, γ-PGA forms a long chain with the following characteristics:
① The backbone is continuously linked by γ-amide bonds;
② Each repeating unit contains one ionizable carboxyl group;
③ Carboxyl groups are densely distributed along the polymer chain;
④ At an appropriate pH, many carboxyl groups are converted into negatively charged carboxylate groups.
The hydrophilicity of γ-PGA does not arise merely because glutamic acid contains carboxyl groups. Rather, these groups are repeatedly arranged along the same polymer chain, creating a continuous region of hydration.
The moisturizing effects of γ-PGA arise from its distinctive chemical structure and polymeric behavior. γ-Amide bonds link the repeating glutamic acid units while preserving numerous ionizable carboxyl groups along the sides of the molecular chain. These hydrophilic groups form dynamic hydration layers with water. As γ-PGA spreads and becomes locally concentrated on the skin surface, the polymer chains overlap and become entangled, forming a hydrophilic film that is not completely occlusive. This may increase hydration at the surface of the stratum corneum and slow water evaporation. The principal process is illustrated below.
3 Why Does Polyglutamic Acid Interact Strongly with Water?
3.1 Carboxyl and carboxylate groups form hydration layers
Water molecules are polar. The negatively charged carboxylate groups on the γ-PGA chain can attract water molecules through ion–dipole interactions and form hydration layers around themselves.
Partially undissociated carboxyl groups, amide carbonyl groups in the backbone, and amide hydrogen atoms can also participate in hydrogen bonding.
The main interactions between the polymer chain and water include:
Carboxylate group–water: ion–dipole interaction
Carboxyl group–water: hydrogen bonding
Amide group–water: hydrogen bonding
Because these hydrophilic groups are densely distributed along the long polymer chain, a single γ-PGA molecule can form a continuous and extensive hydration region.
3.2 Polymer chains organize water into a dynamic hydration system
Small-molecule humectants interact with water mainly through hydroxyl groups, carboxyl groups, or other polar groups on individual molecules. In addition to possessing numerous hydrophilic groups, γ-PGA also exhibits the characteristic volume, conformation, and interchain interactions of a polymer chain.
When γ-PGA enters the aqueous phase, the following processes may occur:
Carboxyl-group hydration → formation of a hydration layer around the chain → changes in chain conformation and hydrodynamic volume → under suitable molecular-weight, concentration, pH, and ionic-strength conditions, an increase in solution viscosity and possible chain overlap and entanglement
Water is not permanently fixed to a particular carboxyl group. Instead, it continuously exchanges among bound, dissociated, and diffusional states. The presence of polymer chains increases the microscopic pathways through which water must move, allowing some water to remain around the polymer and within interchain regions.
Therefore, the moisturizing effects of polyglutamic acid consist of two components:
1. Molecular interactions between hydrophilic groups and water;
2. The effects of polymer chains on water-transport dynamics.
3.3 pH alters carboxyl-group dissociation and interchain interactions
The carboxyl groups on the side chains of γ-PGA can dissociate as the pH changes:
—COOH ⇌ —COO⁻ ＋ H⁺
As the degree of carboxyl-group dissociation increases, the negative charge on the polymer chain also increases. Electrostatic repulsion, intrachain hydrogen bonding, counterion hydration, and interchain entanglement consequently change, thereby affecting the conformation, solution viscosity, and hydration state of γ-PGA.
Experimental studies have shown that when γ-PGA changes from its acidic form to its salt form, its secondary structure, molecular morphology, hydrodynamic size, and viscosity all change. As the concentration increases, the effects of interchain interactions and entanglement also become stronger.[2]
Therefore, the same γ-PGA ingredient may exhibit different viscosity, stringiness, spreadability, and film-forming behavior under different pH and electrolyte conditions.
4 What Happens When Polyglutamic Acid Is Applied to the Skin?
4.1 It spreads with the formulation and becomes hydrated on the skin surface
γ-PGA is generally present in the aqueous phase of serums, gels, emulsions, or facial masks. After the product is spread, the polymer is distributed with the aqueous phase across the surface of the stratum corneum and within the skin’s microrelief.
Because high-molecular-weight γ-PGA has a relatively large hydrodynamic size, it is expected to remain mainly on the skin surface and the outer region of the stratum corneum after topical application. Lower-molecular-weight γ-PGA may diffuse more rapidly within the aqueous phase and across microscopic regions of the skin surface, but a reduction in molecular weight does not necessarily mean that it can cross the intact stratum corneum and enter the viable epidermis or dermis.
After spreading, the carboxyl and amide groups of γ-PGA continue to interact with water in the formulation and with moisture on the skin surface, forming a water-rich polymeric interfacial layer outside the stratum corneum.
4.2 The polymer concentration increases and a hydration network forms
As some of the free water in the product gradually evaporates, the concentration of γ-PGA on the skin surface increases.
The distance between adjacent molecular chains decreases, chain-segment overlap and entanglement increase, and water becomes distributed around the carboxyl groups, along the polymer-chain surfaces, and within interchain regions, forming a dynamic hydration network.
This network does not completely seal in water. However, when its molecular weight, concentration, and film-forming state are appropriate, it may slow the movement and evaporation of water from the skin surface.
4.3 A hydrophilic polymer layer forms when formulation conditions permit
As the water content continues to decrease, γ-PGA may form a continuous or semi-continuous hydrophilic polymer layer on the skin surface.
This layer has three characteristics:
① It is hydrophilic and can absorb and release water;
② It is not a completely sealed hydrophobic film;
③ Its state changes with environmental humidity and the water content of the skin surface.
4.4 The film is gradually removed by water and friction
The polymer layer formed by γ-PGA is reversible. Perspiration, changes in environmental humidity, skin friction, subsequent product application, and cleansing can cause it to become rehydrated, rupture locally, or be gradually removed.
It provides a surface hydration environment that persists for a period of time rather than permanently altering the structure of skin tissue.
5 How Does Polyglutamic Acid Produce Multilevel Moisturizing Effects?
The fundamental moisturizing mechanism of polyglutamic acid can be divided into three consecutive levels.
Level of action | Main structural basis | Effect on skin water |
Molecular hydration | Carboxyl groups, carboxylate groups, and amide groups | Formation of ionic hydration and hydrogen-bonding interactions with water |
Network water retention | Hydration of long chains, together with chain overlap and entanglement at suitable concentrations | May slow water movement within the polymer system |
Surface film formation | Local concentration increases and formation of a polymer layer under suitable formulation conditions | May increase resistance to water diffusion from the surface of the stratum corneum into the air |
These three levels are not independent effects but consecutive processes arising from the same structure:
Interaction of hydrophilic groups with water → organization and retention of water by polymer chains → formation of a surface polymer layer under appropriate conditions, potentially slowing water evaporation
5.1 Increasing hydration at the surface of the stratum corneum
The first effect of γ-PGA is to increase hydration at the skin surface and in the outer layers of the stratum corneum.
As corneocytes absorb water, their flexibility increases, and microscopic surface irregularities of the stratum corneum may temporarily become less pronounced, making the skin feel softer and smoother. Fine lines caused by dryness may also be temporarily reduced as hydration of the stratum corneum increases.
These changes are physical manifestations of increased water content in the stratum corneum. They do not indicate increased dermal collagen or structural alteration of wrinkle tissue.
5.2 Slowing water evaporation from the skin surface
Transepidermal water loss, abbreviated as TEWL, refers to the movement of water from within the skin toward the exterior, followed by its evaporation from the skin surface.
The skin’s principal barrier to water diffusion is located in the stratum corneum, in which the intercellular lipid lamellae composed of ceramides, cholesterol, free fatty acids, and other components are key structures.
The principal structures controlling TEWL are the intercellular lipids of the stratum corneum. γ-PGA cannot replace the lipid barrier formed by ceramides, cholesterol, and free fatty acids, but its hydration network and surface polymer layer can increase resistance to water diffusion into the environment.
Its mechanism differs from that of strongly occlusive oils:
Material type | Main action |
Hydrophilic polymers such as γ-PGA | Humectancy, hydration, viscosity enhancement, and formation of a hydrophilic polymer layer |
Hydrophobic occlusive agents such as petrolatum | Formation of a hydrophobic film with low water-vapor permeability |
Barrier lipids such as ceramides | Participation in the construction of intercellular lipid structures in the stratum corneum |
γ-PGA possesses a structural basis for slowing water evaporation from the skin surface. However, whether a finished product can significantly reduce TEWL still depends on the amount added, molecular weight, film-forming state of the formulation, and oil-phase composition, and must be evaluated through human testing of the complete formulation.
6 Why Does Molecular Weight Affect the Performance of Polyglutamic Acid?
γ-PGA is not a single small molecule with a fixed molecular weight, but a group of polymers with different chain lengths and molecular-weight distributions.
The final molecular weight of γ-PGA may be influenced by the composition of the Pgs synthetase system and the activity of degrading enzymes such as PgdS.[3,7]
6.1 High-molecular-weight γ-PGA
Longer polymer chains generally have larger hydrodynamic volumes and more readily undergo interchain overlap and entanglement. They may therefore exhibit:
① More pronounced viscosity enhancement;
② Greater capacity to form surface networks;
③ More complete polymer films;
④ More pronounced stringiness and viscoelasticity.
When the concentration is too high or the formulation is incompatible, the product may also exhibit tackiness, stringiness, tightness after drying, or pilling caused by interactions with other polymers.
6.2 Lower-molecular-weight γ-PGA
As chain length decreases, solution viscosity and interchain entanglement generally weaken. The ingredient may exhibit:
① Better flowability;
② Less stringiness;
③ Faster diffusion within the aqueous phase;
④ Weaker film-forming and viscosity-enhancing capacity when used alone.
A lower molecular weight may facilitate diffusion into microscopic regions of the stratum corneum surface, but it cannot be used as evidence that γ-PGA is able to enter the dermis.
6.3 Ingredient performance cannot be determined by molecular weight alone
The actual performance of γ-PGA in skincare products is also influenced by the following factors:
Molecular-weight distribution ＋ use concentration ＋ D/L composition ＋ salt form ＋ pH ＋ electrolytes ＋ other polymers
Therefore, even when two products are both labeled as containing polyglutamic acid, they may differ substantially in viscosity, film-forming properties, immediate hydration performance, and sensory characteristics.
7 Does Polyglutamic Acid Affect the Skin’s Own Moisturizing System?
In addition to physical hydration and film formation, some studies have observed effects of γ-PGA on hydration- and barrier-related markers in keratinocytes.
These findings broaden the scope of γ-PGA research, but the available evidence is currently derived mainly from cell studies, reconstructed skin models, and in vitro enzymatic experiments.
7.1 Hyaluronic acid synthesis
A 2025 study treated cultured human keratinocyte cells with a high-molecular-weight γ-PGA sample having an absolute molecular weight of approximately 6,975 kDa. Increased expression of hyaluronic acid synthases 1, 2, and 3, namely HAS1, HAS2, and HAS3, was observed, together with an increase in the amount of hyaluronic acid produced in the cell culture system.[4]
The same study also observed changes in aquaporin 3, abbreviated as AQP3, as well as in filaggrin, involucrin, loricrin, and other related markers. In a reconstructed skin model, topical application of 1% γ-PGA increased the expression signals of filaggrin, involucrin, CD44, and AQP3.[4]
These results indicate that this specific γ-PGA sample can affect hydration-, differentiation-, and barrier-related signaling in keratinocytes. The study did not include human testing; therefore, it remains unclear how much hyaluronic acid an actual skincare product could increase in human skin or to what extent it could alter stratum corneum hydration and TEWL.
7.2 Hyaluronidase inhibition
Evidence that γ-PGA inhibits hyaluronidase is derived mainly from an in vitro enzymatic experiment described in a patent. In this experiment, γ-PGA was placed in direct contact with hyaluronidase and its substrate, and γ-PGA samples of different molecular weights were observed to inhibit enzyme activity.[6]
The direct-contact conditions in an in vitro enzyme solution differ from those of intact skin. After topical application, high-molecular-weight γ-PGA is located mainly on the surface of the stratum corneum, whereas hyaluronic acid metabolism in the skin occurs in areas including the viable epidermis and dermis.
Therefore, hyaluronidase inhibition represents an in vitro activity signal for γ-PGA and cannot, by itself, be used to explain its primary topical moisturizing effects.
7.3 Generation of natural moisturizing factor
Natural moisturizing factor, abbreviated as NMF, is the collective term for low-molecular-weight, water-soluble substances present in corneocytes, including free amino acids, pyrrolidone carboxylic acid, urocanic acid, lactate, urea, and inorganic ions.
Many of these free amino acids and their derivatives are generated through the processing and degradation of filaggrin:
During maturation of the stratum corneum, filaggrin undergoes stepwise proteolysis to form short peptides and free amino acids. Histidine can subsequently be converted into urocanic acid, while glutamine can undergo cyclization to form pyrrolidone carboxylic acid. These free amino acids and their derivatives collectively constitute an important part of NMF.[5,8]
Filaggrin expression is a prerequisite for the formation of NMF. However, an increase in protein expression does not necessarily result in an actual increase in NMF, because keratinocyte differentiation, proteolysis, and subsequent metabolism must also occur.[5]
Existing γ-PGA studies have observed changes in filaggrin expression but have not directly measured increases in pyrrolidone carboxylic acid, urocanic acid, or total NMF in the human stratum corneum. Therefore, γ-PGA may affect upstream processes associated with filaggrin and NMF formation, but whether it can increase total NMF, pyrrolidone carboxylic acid, or urocanic acid levels in the human stratum corneum still requires direct measurement.
8 Classification and Research Applications of Representative Chemicals Related to Polyglutamic Acid Structure, Hydration, Film Formation, and Skin Moisturization Mechanisms
Table 1. Core Polyglutamic Acid Materials, Glutamic Acid Monomers, and γ-Amide Bond Structural Controls
Category | CAS No. | Aladdin Catalog No. | Name | Specification or Purity | Product Features and Applications |
L-Glutamic acid polymer structural control | 25513-46-6 | L-Glutamic acid polymer | Molecular weight ≤100,000 Da | Used to study the molecular weight, carboxyl-group density, solution viscosity, chain conformation, and film-forming properties of polyglutamic acid materials. When used for γ-PGA structural research, its glutamyl linkage pattern should first be confirmed. | |
Sodium poly-γ-glutamate | 28829-38-1 | Sodium polyglutamate (γ-PGA) | ≥92% | Core sodium poly-γ-glutamate material; used to study carboxylate hydration, ionic-strength response, solution rheology, dynamic hydration networks, surface film formation, and moisturizing systems. | |
L-Glutamic acid monomer | 56-86-0 | L-Glutamic acid | Ultrapure grade, ≥99.5% (NT) | L-Configured glutamic acid monomer; used to study the repeating units of polyglutamic acid, carboxyl-group dissociation, amino acid composition, and polymer structure. | |
D-Glutamic acid monomer | 6893-26-1 | D-Glutamic acid | Moligand™, ≥98% | D-Configured glutamic acid monomer control; used to study D/L composition, stereochemical configuration, and differences in monomer composition in fermentation-derived poly-γ-glutamic acid. | |
Glutamate salt-form control | 6106-04-3 | Monosodium L-glutamate monohydrate | Moligand™, ≥99% | Sodium glutamate salt-form control; used to compare the solubility, ionic hydration, acid–base response, and carboxylate behavior of free glutamic acid and its salt form. | |
γ-Glutamyl linkage structural control | 1116-22-9 | γ-L-Glutamyl-L-glutamic acid | ≥98% | γ-Glutamyl dipeptide structural control; used for γ-amide bond identification, linkage-pattern verification, chromatographic analysis, and studies of polyglutamic acid degradation products. |
Table 2. Polyglutamic Acid Hydration, Film Formation, and Small-Molecule Moisturizing Controls
Category | CAS No. | Aladdin Catalog No. | Name | Specification or Purity | Product Features and Applications |
Small-molecule polyol humectant | 56-81-5 | Glycerol | Anhydrous grade, UltraBio™, molecular biology grade, ≥99.5% (GC) | Classical small-molecule humectant; used to compare polyhydroxy-molecule hydration with polymer-network water retention by polyglutamic acid, stratum corneum water content, and moisturizing synergy in formulations. | |
Diol humectant and solvent | 107-88-0 | 1,3-Butanediol | Anhydrous grade, ≥99% | Diol humectant and aqueous-phase solvent; used to study formulation water activity, solvent composition, post-evaporation skin feel, and hydration in combination with polyglutamic acid. | |
Diol humectant and solvent | 57-55-6 | 1,2-Propanediol | ACS, ≥99.5% | Diol humectant and solvent control; used to study small-molecule hydration, formulation solubility, polymer dispersion, and moisturizing synergy with polyglutamic acid. | |
Polyhydroxy moisturizing and barrier-support ingredient | 81-13-0 | D-Panthenol | ≥98% | Polyhydroxy moisturizing and barrier-support ingredient; used to study stratum corneum hydration, transepidermal water loss, skin-barrier recovery, and combination with polyglutamic acid. |
Table 3. Products Related to Hyaluronic Acid Hydration, Composition, and Enzymatic Degradation Research
Category | CAS No. | Aladdin Catalog No. | Name | Specification or Purity | Product Features and Applications |
Hyaluronic acid-degrading enzyme | 37326-33-3 | Hyaluronidase (specific for hyaluronic acid) | Recombinant, EnzymoPure™, expressed in E. coli; ≥1000 U/mg enzyme powder; ≥2000 U/mg protein | Hyaluronic acid-specific degrading enzyme; used to study hyaluronic acid degradation kinetics, polyglutamic acid-mediated enzyme-inhibition screening, and substrate-protection experiments. | |
High-molecular-weight sodium hyaluronate control | 9067-32-7 | Sodium hyaluronate | European Pharmacopoeia (Ph. Eur.) | Anionic polysaccharide polymer moisturizing control; used to study hydration capacity, viscoelasticity, molecular-weight effects, surface film formation, and combination with polyglutamic acid. | |
Acid-form hyaluronic acid polymer control | 9004-61-9 | Hyaluronic acid | Moligand™, from rooster comb | Acid-form hyaluronic acid polymer substrate; used to study hyaluronidase-mediated degradation, polymer hydration, rheological properties, and structural comparison with polyglutamic acid. | |
Hyaluronic acid uronic acid unit | 6556-12-3 | D-Glucuronic acid | Moligand™, ≥98% | Uronic acid constituent of hyaluronic acid; used to study the repeating structure of hyaluronic acid, uronic acid quantification, reference-standard comparison, and related metabolism. | |
Hyaluronic acid amino sugar unit | 7512-17-6 | N-Acetyl-D-glucosamine | ≥98% | Amino sugar constituent of hyaluronic acid; used to study the repeating disaccharide structure of hyaluronic acid, amino sugar quantification, reference-standard comparison, and related metabolism. |
Table 4. Products Related to Natural Moisturizing Factor, Filaggrin Metabolism, and the Stratum Corneum Lipid Barrier
Category | CAS No. | Aladdin Catalog No. | Name | Specification or Purity | Product Features and Applications |
Natural moisturizing factor PCA salt | 28874-51-3 | Sodium L-pyrrolidone-5-carboxylate | 50%, oily | Pyrrolidone carboxylate salt found in natural moisturizing factor; used to study stratum corneum humectancy, water retention, filaggrin degradation products, and natural moisturizing factor quantification. | |
Natural moisturizing factor amino acid | 56-45-1 | L-Serine | Animal-origin-free, USP, Moligand™, European Pharmacopoeia (Ph. Eur.), ≥98.5% | Amino acid component of stratum corneum natural moisturizing factor; used to study free amino acid composition, filaggrin degradation, stratum corneum hydration, and amino acid-based moisturizing systems. | |
Nitrogen-containing small molecule in natural moisturizing factor | 57-13-6 | Urea | UltraBio™, molecular biology grade, ≥99.5% (T) | Nitrogen-containing small molecule in natural moisturizing factor; used to study stratum corneum humectancy, keratin hydration, concentration-dependent moisturization, and combination systems. | |
Natural moisturizing factor amino acid | 56-40-6 | Glycine | UltraBio™, molecular biology grade, ultrapure grade, ≥99% (NT) | Free amino acid component of natural moisturizing factor; used to study stratum corneum amino acid composition, hydrophilicity, osmotic regulation, and multicomponent moisturizing systems. | |
Natural moisturizing factor amino acid | 56-41-7 | L-Alanine | UltraBio™, ultrapure grade, ≥99.5% (NT) | Free amino acid component of natural moisturizing factor; used to study filaggrin-derived amino acid composition, stratum corneum hydration, and amino acid moisturizing controls. | |
PCA acid-form control | 98-79-3 | L-Pyroglutamic acid | UltraBio™, ultrapure grade | Acid-form pyrrolidone carboxylic acid control; used to study natural moisturizing factor composition, the acid form of PCA, glutamine-related cyclization pathways, acid–base forms, and differences in moisturization between acid and salt forms. | |
Histidine and urocanic acid precursor | 71-00-1 | L-Histidine | UltraBio™, ≥99.5% (NT) | Filaggrin-derived amino acid and urocanic acid precursor; used to study histidine metabolism, natural moisturizing factor composition, and stratum corneum photochemistry. | |
Natural moisturizing factor lactate | 72-17-3 | DL-Sodium lactate solution | 73% in water | Lactate component of natural moisturizing factor; used to study stratum corneum humectancy, acid–base balance, water activity, and multicomponent moisturizing systems. | |
Acid-form control for the lactate system | 50-21-5 | DL-Lactic acid | AR, 85–90% | Acid-form lactic acid control; used to study lactic acid and lactate forms, the acidic environment of the stratum corneum, hydration state, and formulation pH. | |
Urocanic acid research control | 104-98-3 | 4-Imidazoleacrylic acid | ≥98% | Compound corresponding to urocanic acid; used to study filaggrin–histidine metabolism, natural moisturizing factor composition, the acid–base environment of the stratum corneum, and ultraviolet absorption. | |
Stratum corneum cholesterol control | 57-88-5 | C432975 | Cholesterol, from lanolin | PharmPure™, JP, BP, European Pharmacopoeia (Ph. Eur.), NF, ultrapure grade | Intercellular lipid component of the stratum corneum; used to study cholesterol content, lipid lamellar structure, membrane ordering, and transepidermal water loss. |
Barrier fatty acid control | 60-33-3 | Linoleic acid | Moligand™, ≥99% (GC) | Essential unsaturated fatty acid; used to study stratum corneum fatty acid composition, acylceramide-related metabolism, lipid ordering, and barrier models. | |
Stratum corneum ceramide control | 100403-19-8 | Ceramide mixture | ≥95% | Stratum corneum ceramide research material; used to study intercellular lipid lamellae, barrier reconstruction, transepidermal water loss, and differences between hydrophilic film formation and the lipid barrier. |
Note: The products listed above are representative Aladdin products related to scientific research and formulation studies. Additional product specifications, grades, and certificate of analysis information can be retrieved from the Aladdin website using the product name, CAS number, or catalog number.
References
[1] Goto A, Kunioka M. Biosynthesis and hydrolysis of poly(γ-glutamic acid) from Bacillus subtilis IFO3335. Bioscience, Biotechnology, and Biochemistry. 1992;56(7):1031–1035. doi:10.1271/bbb.56.1031.
[2] Wang LL, Chen JT, Wang LF, Wu S, Zhang GZ, Yu HQ, Ye XD, Shi QS. Conformations and molecular interactions of poly-γ-glutamic acid as a soluble microbial product in aqueous solutions. Scientific Reports. 2017;7:12787. doi:10.1038/s41598-017-13152-2.
[3] Wei X, Yang L, Chen Z, Xia W, Chen Y, Cao M, He N. Molecular weight control of poly-γ-glutamic acid reveals novel insights into extracellular polymeric substance synthesis in Bacillus licheniformis. Biotechnology for Biofuels and Bioproducts. 2024;17(1):60. doi:10.1186/s13068-024-02501-9.
[4] Ko HJ, Park S, Shin E, Kim J, Lee GS, Lee YJ, Park SM, Lee J, Hyun CG. Poly-γ-glutamic acid from a novel Bacillus subtilis strain: strengthening the skin barrier and improving moisture retention in keratinocytes and a reconstructed skin model. International Journal of Molecular Sciences. 2025;26(3):983. doi:10.3390/ijms26030983.
[5] McAleer MA, Jakasa I, Raj N, O’Donnell CPF, Lane ME, Rawlings AV, Voegeli R, McLean WHI, Kezic S, Irvine AD. Early-life regional and temporal variation in filaggrin-derived natural moisturizing factor, filaggrin-processing enzyme activity, corneocyte phenotypes and plasmin activity: implications for atopic dermatitis. British Journal of Dermatology. 2018;179(2):431–441. doi:10.1111/bjd.16691.
[6] Sung MH, Park C, Choi JC, Uyama H, Park SL. Hyaluronidase inhibitor containing poly-gamma-glutamic acid as an effective component. US Patent US8916141B2. Issued December 23, 2014.
[7] Sawada K, Hagihara H, Takimura Y, Kataoka M. Production and molecular weight variation of poly-γ-glutamic acid using a recombinant Bacillus subtilis with various Pgs-component ratios. Bioscience, Biotechnology, and Biochemistry. 2024;88(10):1217–1224. doi:10.1093/bbb/zbae093.
[8] Hoober JK, Eggink LL. The discovery and function of filaggrin. International Journal of Molecular Sciences. 2022;23(3):1455. doi:10.3390/ijms23031455.
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