N-Medium-and long-chain acyl-L-amino acids were enzymatically synthesized from the corresponding L-amino acids and fatty acids using a reverse hydrolysis. Enzymes that are suitable for the synthetic reaction of N-acyl-L-amino acids were screened on the basis of hydrolytic activity toward N-lauroyl-L-glutamic acid as an indicator. Acylase I from pig kidney (EC 3.5.1.14) showed the highest N-acyl-L-amino acid hydrolytic activity among 57 commercially available enzymes tested. Acylase I effectively catalyzed the synthesis of N-lauroyl-L-amino acids except for Nlauroyl-L-proline and N-lauroyl-L-tyrosine in a glycerol-water system. Under the optimized reaction conditions, N-lauroyl-L-arginine and N-lauroyl-L-glutamic acid were obtained in conversions of 82 and 44%, respectively. The equilibrium constants calculated from the conversion obtained were 5. 6, 15.4, 18.0, and 39.4 for the syntheses of N-lauroyl-L-glutamic acid, N α -lauroyl-L-lysine, Nlauroyl-L-glutamine, and N-lauroyl-L-methionine, respectively. NAcyl-L-arginines with myristic acid and palmitic acid as the fatty acid were also synthesized using acylase I.
A series of sequence-regulated vinyl copolymers with high-order and long vinyl monomer sequences were constructed via a combination of iterative single vinyl monomer additions, which were mediated by radical and cationic intermediates, and subsequent metal-catalyzed step-growth radical polymerization. The construction of vinyl monomer sequences was attained by iterative single monomer radical and cationic additions between a dichloride, having a similar substituent to that of vinyl monomers, and vinyl monomers such as styrenes, acrylates, and acrylonitrile. The resulting products were converted into sequenceregulated ab-type monomers that have embedded vinyl monomer sequences between an unconjugated CC bond and reactive C−Cl bond via selective allylation of one of the two C−Cl bonds at their terminals. The synthesized sequence-regulated ab-type monomers were polymerized via metal-catalyzed stepgrowth radical polymerization, which resulted in vinyl chloride units via repetitive intermolecular addition reactions between the CC and C−Cl terminals. Alternatively, aa-and bb-type sequence-regulated monomers, which have two unconjugated CC and two reactive C−Cl bonds, respectively, were prepared by similar iterative single monomer additions and were subsequently polymerized via metalcatalyzed step-growth radical polymerization. The repeating vinyl monomer sequence codes in the resulting polymers, such as ABCC, ABCD, ABBAC, ABDBAC, and ABDBACAEEAC, varied from 4 to 11 monomer units in which the embedded vinyl monomer units were styrenes, acrylates, acrylamides, acrylonitrile, vinyl chloride, vinylidene chloride, and ethylene.
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