N-lipidated oligopeptides immobilized on cellulose as new type of organocatalysts

A library of supramolecular structures formed by self-organization of N-lipidated tripeptides, dipeptides and N-acylated amino acids attached to cellulose according to the TASP concept via aminophenylamino-1,3,5-triazine was synthesized and the catalytic activity of the structures was studied. Intensive catalytic activity in solvolysis of sterically hindered Z-Aib-Aib-ONp under ambient conditions was observed for structures bearing the catalytic triad as well as for structures with the peptide fragment shortened to a dipeptide or even a single Ser, Glu or His residue, but not for structures bearing alanine or phenylalanine residues. For all structures with a dipeptide or a single amino acid residue and for most of tripeptide structures the progress of solvolysis was stopped after the concentration of the nitrophenolate ion reached 0.5-0.7 x 10-4 M/L. Only in the case of catalysts with glutamic acid residues in the tripeptide fragment, solvolysis proceeded until all the substrate was consumed.