Acylglutamic acid

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). 

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... 

The same enzyme systems appear to be involved in the use of the N-acylglutamic acid derivatives. Whether or not a common intermediate (see reaction 33) is formed is as yet unknown. 

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.]... 

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). 

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. 

Amino acid-based nonionic surfactants are listed in Table 5. Most of the materials are used either as a coemulsifier or as an emollient in skin care and hair care products [28-30]. Acylglutamate cholesteryl ester (AGCE) promotes recovery of damaged skin, which is similar to the effect found for ceramides, key constituents in the lipid membrane of the stratum corneum [31]. 

Oxidative modification of peptides has been performed by ruthenium-catalyzed oxidation with peracetic acid. For example, the reaction of N,C-protected peptides containing glycine residues with peracetic acid in the presence of RUCI3 catalyst gives a-ketoamides derived from the selective oxidation at the C position of the glycine residue (81%, conv. 70%) (Eq. (7.67)) [116]. Direct conversion of N-acylproline to N-acylglutamate was achieved by Ru(TMP)Cl2 and 2,6-dichloropyridine N-oxide (Eq. (7.68)) [117]. 

The possibility exists that under physiological conditions the product of the reaction of ornithine and compound X is an active compound which can react directly with aspartate to form arginosuccinic acid. In absence of the appropriate reaction partner, compound X then decomposes into nonreactive citrulline and acylglutamate. 

Disodium acylglutamate is very similar in structure except it has two anionic groups (Fig. 14), but also requires an acid chloride in its preparation. 

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