Peptides multifunctionalization

J f-(6-Diphenylphosphinopyridine-2-carbonyl)-guanidine, another type of such self-assembling ligands, has been prepared in a 10 g scale by the condensation of diphenylphosphinopyridine-2-carboxyhc acid with Boc-protected guanidine in the presence of the peptide-couphng reaction BOP (Scheme 2.3) [9]. After removal of the Boc-protective group, the multifunctionalized phosphine was ready for screening in several rhodium-catalyzed tandem reactions [10]. 

In a conceptual paper, Matile et al. described that CT-DNA can be activated by amphiphilic cations such as guanidiniocalixarenes 7 to act as a cation transporter in bulk and Upid bilayer membranes and showed that this unusual activity of DNA can be of interest for the development of biosensors (Fig. 24.32). In light of the chargebalancing effect of cell-penetrating peptides as anion transporters across lipid membranes, this discovery demonstrates that the multifunctionality of polyion-counterion complexes is general and occurs with low-basicity polyanions exactly as with low-acidity polycations [100]. 

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