赖氨酸环二肽有机凝胶因子的合成及其选择性凝胶化与染料吸附

在利用半胱氨酸修饰赖氨酸环二肽制备对称性四肽的过程中, 通过两种脱除Trt(三苯甲基)的方法分别得到含有Fmoc(芴甲氧羰基)的非环与大环四肽产物, 其结构得到了核磁、质谱、红外、元素分析等证实。 它们能使多种有机溶剂凝胶化, 且具有热可逆性, 由扫描电子显微镜(SEM)可观察到凝胶内部均为三维网络结构。 在体积分数低至0.1%的含氯有机溶剂/水两相体系中, 它们依然可以进行选择性凝胶化。 此外, 该有机凝胶干胶由于内部微纳米网络结构以及Fmoc基团的存在, 可以直接从水溶液中吸收多种染料分子, 且吸附能力随温度的升高而提高。

Synthesis of Cyclo(L-Lys-L-Lys)-Based Organogelators and Their Applications for Phase-Selective Gelation and Dye Adsorption

One linear and one macrocyclic tetrapepitides(4 and 5) with Fmoc were synthesized by two ways of Trt protection group cleavage in the preparation of symmetrical tetrapepitides using cysteine-modified cyclo(L-Lys-L-Lys) diketopi-perazines. Both tetrapepitides show excellent capability to gelate a number of organic solvents to give thermo-reversible organogels. The self-assembled fibrillar networks in the organogels were distinctly observed by SEM. Interestingly, two organogelators could selectively gelate common chlorinated organic solvents from their mixture with water, even at a concentration as low as 0.1%(volume fraction). Moreover, the xerogel obtained from the organogel of compound 4 in chloroform can high efficiently adsorb various tested dyes from aqueous solutions due to the larger specific surface area of 3D xerogel network showing a micro- and nano-sized structure and the π-π interaction between dye molecules and Fmoc protection groups. The absorption capacity of the xerogel for those dyes increases with the temperature.