An Approach to Nanobioparticles - Synthesis and Characterization of Fulleropeptides

Two sets of new peptides incorporating fulleropyrrolidine units – Fp‐GABAn‐Glym‐OtBu – have been designed, synthesized and completely characterized. In the first series the chain contained only GABA (γ‐aminobutyric) residues, whereas in the second one glycine moieties were also inserted as well as GABA. Most of the target compounds were prepared by DCC/DMAP‐assisted coupling of previously synthesized GABA‐containing fulleropyrrolidinic acid and corresponding C‐protected small peptides, although for two fulleropeptides [3+2] cycloadditions of azomethine ylides to C60 were employed. All new compounds were characterized by standard spectroscopic methods. Complete assignments of peptide spin systems were achieved by extensive NMR analysis (1H, 13C, H,H‐COSY, HSQC, HMBC and TOCSY). The synthesis of 11 new fulleropeptides Fp‐GABAn‐Glym‐OtBu (n = 1–3, m = 0–2) containing 4‐aminobutyric acid (GABA) and glycyl residues was achieved either by DCC/DMAP‐assisted amidation or by [3+2] cycloaddition. In addition, the complete assignment of the peptides' spin systems was accomplished by extensive NMR analysis.