Neobvyklá stechiometrie kalixaren-močovinových derivátů

Calix[4]arenes bearing two p-nitrophenyl-ureido functions at the upper rim are effective anion binders. The stoichiometry of complexation depends on the substitution pattern (distal vs proximal) and anion concentration. While the distally substituted receptor forms 1:1 complexes with anions, the corresponding proximal derivative prefers the 2:1 stoichiometry (calixarene: anion) under identical conditions

A Structure‐Activity Investigation on Modified Analogues of an Argininocalixarene Based Non‐viral Gene Vector

AbstractThe tetra‐L‐arginino‐tetrahexyloxycalix[4]arene 1 has shown extraordinary abilities to compact and internalize different types of Nucleid Acid cargos (DNA, microRNA, PNA) into cells even known to be transfected with great difficulties by commercial non‐viral gene delivery systems. This activity, accompanied by negligible toxicity, makes this calixarene a rather promising prototype of vector for Gene Therapy. In this study we report how small structural changes like i) the lower rim alkyl substituents, ii) the type of the terminal cationic headgroups (guanidinium or primary ammonium), iii) the length of the linker between the macrocycle and the terminal cationic headgroup, iv) the presence/absence of the basic α‐amino group of Arg, and v) the stereochemistry (L or D) of Arg, might affect the ability of the novel calixarene vectors to compact DNA and to deliver its cargo into the cells