Acylglutamates

In Cosmetics. Amino acids and their derivatives occur in skin protein, and they exhibit a controlling or buffering effect of pH variation in skin and a bactericidal effect (216). Serine is one component of skin care cream or lotion. Ai-Acylglutamic acid triethanolamine monosalt is used for shampoo. Glucose glutamate is a moisturizing compound for hair and skin (234). 

Surfa.cta.nts, Ai-Acylglutamates, sodium A/-lauroyl sarcosinate [137-16-6] and A/-acyl-alanine Na salt are used in the cosmetic field as nontoxic surfactants (237). Some of them (eg, A/-acylglutamic acid dibutylamide) are used as oil geUating agents to recover efduent oil in seas and rivers (238). 

Acylglutamate. [Ajinomoto] Glutamates detergent, emollient for personal cate prods. 

Formula NaOOCCH2CH2CHNHCROCOONa, RCO- rep. coconut fatty acids Toxicology TSCA listed Uses Surfactant, detergent, emollient for cosmetics bacteriostat corrosion inhibitor Trade Name Synonyms Acylglutamate CS-21 t[Ajinomoto http //www.ajinomoto.co.jp, http //www.ajinomoto.com], Plantapon ACG 35 [Cognis/Care Chems.]... 

Features Bacteriostatic effect Trade Name Synonyms Acylglutamate MS-11 t [Aj i n o m oto http //www. ajinomoto. co.Jp, http //www.aJinomoto.com]] Amisoft MS-11 [Aj i nom oto http //www.aJinomoto. co.Jp] http //www.aJinomoto.com] Ajinomoto USA http //www.aJinomoto-usa.com]... 

Strontium thioglycolate 38462-22-5 p-Mentha-8-thiol-3-one 38517-23-6 Acylglutamate HS-11 Amisoft HS-11P Sodium stearoyl glutamate 38517-37-2 Amisoft MS-11 Sodium myristoyl glutamate 38521-51-6... 

Acetylated oxidized starch 68187-29-1 Acylglutamate CT-12 Amisoft CT-12 TEA-cocoyl-glutamate 68187-30-4 Acylglutamate CS-21 Disodium cocoyl glutamate Plantapon ACG 35 68187-32-6 Acylglutamate CS-11 Amisoft CS-11 Amisoft CS-22 Hostapon CCG Hostapon KCG Pionier GCK Sodium cocoyl glutamate 68187-69-9 Ethoquad HT/25... 

Takehara et al. also investigated the physicochemical properties of acylamino acid and found them to have superior surface activities at the weakly acidic pH around 5-6, similar to skin pH, even its anionic character [33,34]. Further, they developed various application formulas, such as solid cleansers, shampoo, and creamy or paste-type facial cleansers for acylglutamate [35]. These various research efforts led to the commercialization of acylglutamate in 1972 less than a decade later, a new market was established in Japan for mild cleansers [36]. This is the first commercial application of acylamino acid to have a significant impact on the personal care industry. Since then, many amino acid derivatives, such as acylsarcosinate and acylmethytaurate, have been utilized for personal care products. The applications of acylglutamate have been further extended to almost all types of personal care applications due to the mildness features that the market demands. 

Recently, several acylglutamates (Amisoft), sodium salt of OL-pyrrolidone carboxylic acid derived from L-glutamic acid (Ajidew), lauryl phytosteryl glutamate (Eldew PS-203), lauryl cholesterol (or 2-octyldodecanol and behenol) (Edeu CL-301) have been developed by Ajinomoto Company (Ajinomoto Co. s report, 1994-97). 

The Krafft points of monosodium salts of A-acylglutamic acids were determined by the eiectric conductivity method. The Krafft points were a few degrees beiow the ciear points, the temperatures at which the surfactant dissolved completely [4]. The monosodium salt of A-oleoyl-L-glutamic acid hardly hydrolyzed because it had an affinity with water and the Krafft point is lower. Triethanolamine salts of A-acylglutamic acid are generally more soluble in water and less irritating on the skin and have a lower Krafft point, compared with the corresponding sodium salts. 

TABLE 1 Krafft Point of Monosodium Salts of At-Acylglutamic Acids... 

Protein-based surfactants are composed of two naturally occurring moieties, amino acid and fatty acid such as acylglutamate. Acylglutamates by themselves are not ultramild surfactants by any means. Their in vitro Zein values are higher than those of alkyl polyglycosides, alkylamphoacetate, amphoteric... 

In the United States and Europe, the mildness concept is led by isethionate for a cleansing bar by Lever Brothers (Unilever Affiliate), followed by an amphoteric surfactant and nonionic alkylglycocide, which are really secondary surfactants to reduce the potential for irritation with a combination of typical anionics. The utilization of acylamino acid surfactants has just started in Western markets. In Europe, Biersdorf was the first company to use acylglutamate in a product for the mass market, although several upscale cosmetic cleansers pioneered its use on a small scale. 

In the United States, Germain Monteil first applied acylglutamate to facial cleansers in the mid-1980s, but the market was not yet ready to acknowledge such mild products at that time. Recently, a major launch has been achieved by Bath Body Works for their bath product with acylglutamate in the formula. 

Skin penetration by acylglutamate has been found rather small compared to that of soap or alkylsulfate. The cytotoxicity of acylglutamate for human keratinocyte was significantly lower than for other anionics, including acyl-methyltaurate, as shown in Fig. 7. 

Thus acylglutamate has been demonstrated by several tests to show extreme mildness when tested in vivo with animals and humans or when the actual product is used. Acylmethyltaurate also showed a relatively lower irritation potential by these test methods. 

Sometimes there are difficulties in combining acylglutamate as cosurfactant to the traditional anionic surfactant system in terms of the viscosity and lathering of shampoo or bath cleansers. Acylsarcosinate and acyhnethylalaninate can be used as a tertiary cosurfactant or as an alternative to acylglutamate for this purpose [19], Acylmethyltaurate has also been used as a primary surfactant for mild-shampoo formulation [20,21]. 

---