Ohta Akio, Shirai Mari, Asakawa Tsuyoshi, Miyagishi Shigeyoshi
Division of Material Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa, Ishikawa, Japan.
J Oleo Sci. 2008;57(12):659-67. doi: 10.5650/jos.57.659.
The aggregation behaviors of three stereoisomers of tetramethylammonium N-dodecanoyl phenylalanylphenylalaninate in dilute aqueous solution were investigated. From surface tension, fluorescence intensity using probes, and heat of dilution measurements, it was suggested that the critical aggregation concentration was the same between the enantiomers, but was obviously different between the diastereomers. It was also found that these surfactants formed large aggregates at lower concentrations. These large aggregates were then transformed to micelles at higher concentrations similarly to the potassium N-acyl phenylalaninate system. Furthermore, the fluorescence intensity of auramine increased strikingly in the N-dodecanoyl-L-phenylalanyl-L-phenylalanine (homo-chiral dipeptide-type surfactant) system. The fluorescence intensity of auramine in the aggregate of homo-chiral dipeptide-type surfactant was 20 times larger than that in the hetero-chiral dipeptide-type surfactant.
研究了N-十二烷酰基苯丙氨酰苯丙氨酸四甲基铵的三种立体异构体在稀水溶液中的聚集行为。通过表面张力、使用探针的荧光强度以及稀释热测量表明，对映体之间的临界聚集浓度相同，但非对映体之间明显不同。还发现这些表面活性剂在较低浓度下形成大聚集体。然后，与N-酰基苯丙氨酸钾体系类似，这些大聚集体在较高浓度下转变为胶束。此外，在N-十二烷酰基-L-苯丙氨酰-L-苯丙氨酸（同手性二肽型表面活性剂）体系中，金胺的荧光强度显著增加。同手性二肽型表面活性剂聚集体中金胺的荧光强度比杂手性二肽型表面活性剂中的大20倍。
