title: Fullerene-derivatized amino acids: synthesis, characterization, antioxidant properties, and solid-phase peptide synthesis.
abstract: A series of [60]fullerene-substituted phenylalanine (Baa) and lysine derivatives have been prepared by the condensation of 1,2-(4'-oxocyclohexano)fullerene with the appropriately protected (4-amino)phenylalanine and lysine, respectively. Conversion of the imine to the corresponding amine is achieved by di-acid catalyzed hydroboration. The reduction of the imine is not accompanied by hydroboration of the fullerene cage. The [70]fullerene phenylalanine derivative has also been prepared as have the di-amino acid derivatives. The compounds were characterized by MALDI-TOF mass spectrometry, UV/Vis spectroscopy, and cyclic voltammetry. 1H and 13C NMR spectroscopy allowed the observation of diastereomers. Fullerene-substituted peptides may be synthesized on relatively large scale by solid-phase peptide synthesis. The presence of the C60-substituted amino acid in a peptide has a significant effect on the secondary structures and self-assembly properties of peptides as compared to the native peptide. The antioxidant assay of Baa and a Baa-derived anionic peptide was determined to be significantly more potent than Trolox.
authors.affiliation: Richard E. Smalley Institute for Nanoscale Science and Technology, The Institute of Biosciences and Bioengineering, and Center for Biological and Environmental Nanotechnology, Rice University, Houston, Texas 77005, USA.
authors.forename: Jianzhong
authors.initials: J
authors.lastname: Yang
authors.forename: Lawrence B
authors.initials: LB
authors.lastname: Alemany
authors.forename: Jonathan
authors.initials: J
authors.lastname: Driver
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Hartgerink
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Barron
mesh_terms: D000596:Amino Acids / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D000975:Antioxidants / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D037741:Fullerenes / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D046529:Microscopy, Electron, Transmission; D010455:Peptides / Q000138:chemical synthesis*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000596:Amino Acids; D000975:Antioxidants; D037741:Fullerenes; D010455:Peptides