Amino acid surfactants

Amino acid Surfactant from agarose Surfactant from soil... 

Chiral micellar solubilization may involve the use of chiral surfactants, or a combination of achiral surfactants and a chiral selector. Terabe [26] and Bereuter [25] provide a comprehensive overview of applications involving chiral surfactants such as bile salts or synthetic amino acid surfactants. The use of cyclodextrins (CD) as the chiral selector in combination with MEKC was successful for the separation of neutral racemic nonsteroidal aromatase inhibitors and barbituates [38]. Further approaches to the separation of enantiomers utilizing a combination of CD-MEKC have been described in the review by Terabe [26]. 

Often a cosolvent is used in order to solubilize particularly polar substrates such as sugars and amino acids. Surfactants or additional solvents may also allow adequate solvation of enzymes. In some cases two-phase systems can be used to conduct bioconversion. For example, Reetz and coworkers employed both SCFs and ionic liquids in a semi-continuous... 

Wolf, S. G., Leiserowitz, L., Lahav, M., Deutsch, M., Kjaer, K., and Als-Nielsen, J. Elucidation of the two-dimensional structure of an a-amino acid surfactant monolayer on water using synchrotron X-ray diffraction. Nature (London) 328, 63 -66 (1987). 

Protein instability mechanisms have been reviewed by several investigators.3-13 Chemical reactions such as oxidation, deamidation, proteolysis, racemization, isomerization, disulfide exchange, photolysis, and others will give rise to chemical instability. It is critical that when this happens, the denaturation mechanisms must be identified in order to select appropriate stabilizing excipients. These chemical excipients may be in the form of amino acids, surfactants, polyhydric alcohols, antioxidants, phospholipids, chelating agents, and others. 

Behenamidopropyl PG-dimonium chloride Dipalmitoyl hydroxyproline Disodium oleth-3 sulfosuccinate Palmitoyl collagen amino acids Undecylenoyl collagen amino acids surfactant, bath oils Isostearoyl hydrolyzed collagen surfactant, bath oils blooming Myreth-3 myristate surfactant, beverages Licorice (Glycyrrhiza glabra) root extract surfactant, biocides Cocamidopropyl hydroxysultaine N,N-Dimethyl-N-lauric acid-amidopropyl-N-(3-sulfopropyl)-ammonium betaine N,N-Dimethyl-N-myristyl-N-(3-sulfopropyl)-ammonium betaine N,N-Dimethyl-N-palmityl-N-(3-sulfopropyl)-ammonium betaine N,N-Dimethyl-N-stearyl-N-(3-sulfopropyl)-ammonium betaine... 

Dimethylsiloxane/EO-PO copolymer surfactant, finishing PEG-66 trihydroxystearin surfactant, fire fighting foams TIPA-lauryl sulfate surfactant, first aid creams Palmitoyl collagen amino acids surfactant, floor finishes Nonoxynol-30 Nonoxynol-40 Nonoxynol-50 surfactant, floor polishes Dimethyl hexynol surfactant, floor waxes Oleth-25... 

Behenamidopropyl PG-dimonium chloride surfactant, shaving creams Dipalmitoyl hydroxyproline TEA-myristoyl hydrolyzed collagen Undecylenoyl collagen amino acids surfactant, shower gels Sodium laureth-4 carboxylate Sodium laureth-... 

Amino acid-based surfactants are derived from simple amino acids or mixed amino acids from synthesis or protein hydrolysates. They are composed of amino acid as the hydrophilic part and a long hydrocarbon chain as the hydrophobic part. The hydrophobic chain can be introduced through acyl, ester, amide, or alkyl linkage. Interest in amino acid surfactants is not new, as shown by early work in the area. In 1909, Bondi performed the first research on the introduction of a hydrophobic group to obtain A-acylgiycine and A-acyla-lamine [18], Subsequent work in this area focused on A-acylamino acids, as reported by Funk [19], Izar [20], Karrer [21], Staudinger and Becker [22],... 

FIG. 1 Relationship of acyl group chain length of amino acid surfactants to critical micelle concentration (cmc). (From Ref. 53.)... 

TABLE 1 Correlation Between Log MIC for Microorganisms and Log CMC of Amino Acid Surfactants ... 

Amino acid surfactants of the general structure (X-amino-(iV-acyl)-P-alkoypropionate. Y = log MIC X = log CMC. 

The subsequent chapters will discuss the following areas in greater detail structure-function of proteins, with specific reference to their surface property/interfacial behavior, amino acid surfactants, both chemically and enzymatically synthesized peptide surfactants and potential applications and the market assessment of PBS. 

Amino Acid Surfactants Chemistry, Synthesis, and Properties... 

Amino acid surfactants (AAS), both natural and synthetic types, have been the subject of many smdies, due mostly to their huge potential application in pharmaceutical, cosmetic, household, and food products. The AAS are derived from acidic, basic, or neutral amino acids. Amino acids such as glutamic acid, glycine, alanine, arginine, aspartic acid, leucine, serine, proline, and protein hydrolysates have been used as starting materials to synthesize AAS commercially and experimentally. Methods of preparation include chemical, enzymatic, and chemoenzymic processes, although chemical processes have been prevalent due to their relatively low cost of production. In recent years, more research papers have focused on the use of enzymatic methods to synthesize AAS. It is our opinion that the enzymatic approach would be more attractive to manufacturers in the near future. 

III. STRUCTURAL SCHEMES AND METHODS FOR THE PREPARATION OF AMINO ACID SURFACTANTS... 

A schematic of routes for the synthesis of amino acid surfactants is shown in Fig. la representative structures are illustrated in Fig. lb. The Schotten-Baumann method is a typical and useful way to synthesize A -acylamino acid. 

FIG. 1 (a) Schematic of routes for the synthesis of amino acid surfactants. 

FIG. 1 Continued, (b) Representative structures of amino acid surfactants. R Long chain alkyl radical Rh Amino acid s sidechain R Alkyl radical, etc. 

TABLE 5 Surface Properties of Acyl Amino Acid Surfactants in Aqueous Solution... 

TABLE 6 Minimum Inhibitory Concentration (MIC) of Amino Acid Surfactants for Different Microorganisms... 

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