title: Total synthesis and biological evaluation of PF1171A, C, F, and G, cyclic hexapeptides with insecticidal activity.
abstract: The total synthesis of the cyclic hexapeptides PF1171A, C, F, and G has been achieved by solid-phase synthesis of a linear precursor and solution-phase macrolactamization. The synthesis includes a solid-phase peptide coupling with the weakly nucleophilic amino group of an anthranilic acid residue. This was efficiently achieved by in situ generation of an Fmoc-amino acid chloride using triphosgene. The natural products exhibit potent paralytic activities against silkworm larvae, whereas epi-PF1171A and epi-PF1171C, bearing l-Ala instead of d-Ala, were relatively inactive. X-ray crystallographic analysis indicates that intramolecular hydrogen bonds in PF1171 peptides are critical for maintaining their active conformations.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Tohoku University , 6-3 Aza-Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8578, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Masuda
authors.forename: Ren
authors.initials: R
authors.lastname: Tanaka
authors.forename: Kenji
authors.initials: K
authors.lastname: Kai
authors.forename: A
authors.initials: A
authors.lastname: Ganesan
authors.forename: Takayuki
authors.initials: T
authors.lastname: Doi
mesh_terms: D000595:Amino Acid Sequence; D005075:Biological Evolution; D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D007306:Insecticides / Q000737:chemistry* / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D010456:Peptides, Cyclic / Q000138:chemical synthesis* / Q000737:chemistry; D060327:Solid-Phase Synthesis Techniques
chemical_list: D007306:Insecticides; C000599756:PF1171A; C000599757:PF1171C; D010456:Peptides, Cyclic