界面活性剤ミセルの酵素類似型触媒機能の解明と応用

金沢大学工学部研究課題/領域番号:X00210----075187, 研究期間(年度):1975出典：「界面活性剤ミセルの酵素類似型触媒機能の解明と応用」研究成果報告書　課題番号：X00210----075187（KAKEN：科学研究費助成事業データベース（国立情報学研究所）） （https://kaken.nii.ac.jp/ja/grant/KAKENHI-PROJECT-X00210----075187/）を加工して作

Aqueous solution properties of pyridinium-type perfluorinated surfactants and simulation of mixture CMC

The critical micelle concentrations (CMCs) of 1,1,2,2-tetrahydroperfluoroalkylpyridinium chloride have been determined by measurements of surface tension and electrical conductivity, etc. The CMCs of perfluorinated surfactants were only about 0.02 times that of hydrocarbon one with the same carbon number. Aqueous solutions of fluorocarbon surfactants gave low surface tensions in comparison with those of hydrocarbon surfactants. The area per surfactant molecule at the airâwater interface decreased with increasing length of the fluorocarbon chain. Electromotive force measurements were made with chloride-responsive electrodes on surfactants solutions. The micelle ionization degrees decreased with increasing length of the alkyl chain. The group contribution method simulated the mixture CMCs of binary surfactants with various alkyl chain lengths. The group contribution method proved to be very useful to predict not only the mixture CMCs but also the demixing regions of binary mixtures having great differences in CMC

Convenient Estimation for Counterion Dissociation of Cationic Micelles Using Chloride-Sensitive Fluorescence Probe

Chloride-sensitive fluorescence probe provides a new approach to studying the degree of micellar counterion dissociation (α). The fluorescence of N-ethoxycarbonylmethyl-6-methoxyquinolinium bromide (MQAE) is quenched by chloride ion with linear Stern–Volmer plots. Thus the fluorescence intensity can be used to monitor the concentration of free chloride ion in micellar solutions. The Stern–Volmer plot gave a distinct break at critical micelle concentration (CMC) due to the counterion binding to micelles. The estimated α and CMCs of cationic surfactants including fluorocarbon ones were in fair agreement with the reported experimental values. The MQAE has greater sensitivity to bromide ion of CTAB than chloride ion of CTAC. The α of 0.16 for CTAB micelles was almost constant up to 0.2 M CTAB at 35°C. The α values of CTAB micelles decreased with increasing the concentrations of CTAB and NaBr along with micellar growth

Krafft temperature and enthalpy of solution of N-acyl amino acid surfactants and their racemic modifications: Effect of the amino acid residue

金沢大学工学部The Krafft temperatures and the enthalpies of solution of six kinds of N-hexadecanoyl amino acid surfactant (Gly, Ala, Val, Leu, Ile, and Phe) were obtained from both solubility measurements and differential scanning calorimetry. It was shown that the Krafft temperature of N-hexadecanoyl amino acid surfactant increased with decreasing size of the amino acid residue except for the case of phenylalanine. On the other hand, the enthalpy of solution was endothermic and increased with decreasing size of the amino acid residue except for the cases of glycine and phenylalanine. It was found from these results that the D-L interaction was superior to the L-L interaction in solid state of N-hexadecanoyl amino acid surfactant salt for both the alanine and phenylalanine systems. It was suggested by ab initio calculations that the difference of the magnitude of the peptide-peptide hydrogen bonding was the dominant factor for the chiral effect

Krafft temperature and enthalpy of solution of N-acyl amino acid surfactants and their racemic modifications: Effect of the counter ion

金沢大学工学部The Krafft temperatures and enthalpies of solution of N-hexadecanoyl alaninate and valinate, and N-tetradecanoyl phenylalaninate were obtained from differential scanning calorimetry. The Krafft temperature of N-acyl amino acid surfactant increased with decreasing size of the counter ion, with some exceptions. The enthalpy of solution was endothermic and increased with decreasing size of the counter ion except for the cases of lithium salt. The results showed that the L-L interaction in the solid state of N-hexadecanoyl amino acid surfactant salt was superior to the D-L interaction for both the alanine and valine systems when the counter ion size increased. However, the D-L interaction was still advantageous for the phenylalanine system with Cs+ as a counter ion. Both Fourier transform infrared spectroscopy studies and theoretical calculations suggested that the difference in magnitudes of the interactions between peptide and counter ion was a dominant factor for the chiral effect

Effect of the side chain of N-acyl amino acid surfactants on micelle formation: An isothermal titration calorimetry study

金沢大学大学院自然科学研究科物質情報解析The enthalpy of micelle formation, critical micelle concentration (CMC), and aggregation number of micelles for seven amino acid type surfactants, sodium N-dodecanoyl-glycinate (C12Gly), -l-alaninate (C12Ala), -l-valinate (C12Val), -l-leucinate (C12Leu), -l-phenylalaninate (C12Phe), -l-glutaminate (C12Gln), and -l-threoninate (C12Thr), were obtained at three temperatures ranging from 288.15 to 308.15 K by isothermal titration calorimetry. The enthalpies of micelle formation for these surfactants were positive at 288.15 K and decreased with increasing temperature to ultimately become negative above 308.15 K. The CMC of the amino acid surfactants decreased monotonously with increasing hydrophobicity of the amino acid residue without exception, while with the exception of the C12Phe system, the enthalpy of micelle formation increased. The micellization behavior of C12Phe also deviated from that of other amino acid systems in terms of the heat capacity and the aggregation number. These results suggest the presence of a strong intra-micelle interaction between the side chains of phenylalanine. © 2007 Elsevier B.V. All rights reserved

(R)-1-phenylethylammonium N-tetradecanoyl-L-phenylalaninate monohydrate

金沢大学理工研究域物質化学系The title compound, C8H12N+·C 23H36,NO3-·H2O, has one molecule of N-tetradecanoyl-L-phenylalanine and one molecule of (R)-l-phenylethylamine as a diastereoisomeric salt, and a water molecule in the asymmetric unit. In the crystal structure, the packing of the molecules is stabilized by N - H⋯O and O-H⋯O hydrogen bonds involving the amide, ammonium and carboxylate groups, and the solvent water molecule. © 2006 International Union of Crystallography Printed in Great Britain - all rights reserved

Unique incorporation behavior of amino acid-type surfactant into phospholipid vesicle membrane

金沢大学工学部The incorporation behavior of some anionic surfactants, including amino acid-type surfactants, on phospholipid vesicles was investigated. This was done by measuring the release of a vesicle-entrapped fluorescence probe and the scattered light intensities of vesicle particles in the surfactant solution as a function of surfactant concentration and time. Sodium dodecyl sulfate, sodium dodecanesulfonate, sodium dodecanoyl sarcosinate, and sodium dodecanoyl glutamate were employed in this study. All surfactants ruptured the phospholipid vesicle at around each critical micelle concentration by mixed micelle formation with phospholipid. While leakage of the fluorescence probe took place at a very low concentration in the sulfate- or sulfonate-type surfactant systems, it occurred at the concentration just below the CMC in the amino acid-type surfactant systems. Kinetic analysis of the release of the probe from the vesicles showed that the former surfactants adsorbed independently and homogeneously onto the phospholipid vesicles, while the latter surfactants were cooperatively incorporated

Phase diagrams of mixtures of diastereomeric salts of N-acyl amino acid-type surfactants and separation of enantiomers

金沢大学理工研究域物質化学系An amino acid surfactant having an optically active base as a counterion was synthesized by neutralization of N-acyl amino acid with 1-phenylethylamine (PEA). Phase diagrams of diastereomeric mixtures of R-PEA N-acyl DL-amino acid and RS-PEA N-acyl D-amino acid systems were obtained by differential scanning calorimetry. The functions of N-acyl amino acids and PEA as optical resolving agents were examined by drawing the phase diagrams. FT-IR studies suggested that the difference in the magnitude of the interaction between the amide groups was a dominant factor affecting the difference in the physicochemical properties between the diastereomers