Generation of Biomembrane Functions in Organic Solvents and Its Application

合成了l -谷氨酸衍生的脂质，研究了其在有机溶剂中的聚集结构，并探讨了聚集的驱动力。a)由l -谷氨酸衍生的含三酰胺类脂质通过酰胺段之间的氢键相互作用形成脂质聚集形成有机凝胶。这种凝胶在甲醇、乙醇、苯、四氢呋喃、甲苯和环己烷等多种有机溶液中形成。b)透射电镜观察表明，透明凝胶冷冻干燥后的干凝胶是由微纤维聚集体网络构成的。但在低浓度（溶胶状态）下没有观察到类似的网络，而可以检测到碎片状的微纤维。结果表明，临界胶凝作用与有机溶剂的种类有关。例如，室温下的cgc在苯中在1 ~ 0.1 mM之间。然而，扫描电镜和透射电镜观察表明，与cgc相比，在0.01 mM的离子浓度下产生的纤维聚集体更低。这表明cgc与临界聚集浓度（cac）不一致。因此，凝胶的形成归因于纤维聚集体的发展和随后形成的聚集体网络。c)为了估计cac和聚集体结构，我们合成了具有芘基头基的新脂质。荧光发射光谱显示脂质产生的准分子浓度在cac以上。d)我们合成了含有四烷基和原卟啉ix头基的l -谷氨酸脂质三酰胺。脂质在苯、环己烷等有机溶液中产生高取向纤维聚集体。紫外-可见光谱表明形成了一个Soret波段，该波段是通过红移现象估计的，但通过添加三氟乙酸（TFA）来提供与单体色散态相对应的光谱，从而消除了这些波段。CD光谱结果表明，聚集体对棉花产生正向效应，而TFA的加入降低了棉花的椭圆度。这些结果表明，氢键作用是聚集的驱动力，并将包括共面填充卟啉平面结构。少

L-glutamic acid-derived lipids were synthesized in order to study the aggregation structures in organic solvents and discussed the driving force for aggregation.a) Triamide-containing lipids derived from L-glutamic acid produced organic gels through formation of lipid aggregation by hydrogen bonding interaction among the amide moieties. This gelation was formed in various organic solution such as methanol, ethanol, benzene, tetrahydrofuran, toluene and cyclohexane.b) TEM observation showed that the xerogel after freeze-dried from the clear gel was constructed from a network of microfibrous aggregates. But no similar network was observed at the low concentration (in the sol state) while fragmental microfibers were detectable. It was confirmed that critical gelation (cgc) depended on the kind of organic solvents. For example, the cgc lies between 1 and 0.1 mM at room temperature in benzene. However, SEM and TEM observations showed that fibrous aggregates were produced at lower concentrat … More ion such as 0.01 mM than cgc. This shows that the cgc doesn't agree with the critical aggregation concentration (cac). Therefore, the gel formation is attributed to the development of fibrous aggregates and subsequent formation of an aggregate network.c) To estimate cac and the aggregation structure, we synthesized new lipids having pyrenyl head group. By fluorescence emission spectra showed that the lipids produced excimers at the concentration above cac.d) We synthesized triamide-containing L-glutamic acid lipid with tetraalkyl groups and a protoporphyrin IX-head group. The lipid produced highly-oriented fibrous aggregates in organic solution such as benzene, cyclohexane and so on. UV-vis spectra indicated formation of a Soret band which was estimated by red shift phenomena, but these were lost by addition of trifuluoroacetic acid (TFA ) to provide spectra corresponding to those in monomeric dispersion states. CD spectra showed that the aggregates induced positive Cotton effect but addition of TFA reduced the elipticity. These results indicate that hydrogen bonding work as a driving force for aggregation and the cofacial packed-porphyrin planar structure will be included. Less