1. A new class of aggregation inhibitor of amyloid-β peptide based on an O-acyl isopeptide
Hiroyuki Kawashima, Youhei Sohma, Tomoya Nakanishi, Hitomi Kitamura, Hidehito Mukai, Masayuki Yamashita, Kenichi Akaji, Yoshiaki Kiso Bioorg Med Chem. 2013 Nov 1;21(21):6323-7. doi: 10.1016/j.bmc.2013.08.062. Epub 2013 Sep 7.
Inhibition of amyloid β peptide (Aβ) aggregation is a potential therapeutic approach to treat Alzheimer's disease. We report that an O-acyl isopeptide of Aβ1-42 (1) containing an ester bond at the Gly(25)-Ser(26) moiety inhibits Aβ1-42 fibril formation at equimolar ratio. Inhibitory activity was retained by an N-Me-β-Ala(26) derivative (2), in which the ester of 1 was replaced with N-methyl amide to improve chemical stability at physiological pH. Inhibition was verified by fluorescence anisotropy, Western blot, and atomic force microscopy. This report suggests a new class of Aβ aggregation inhibitor based on modification of Aβ1-42 at Gly(25)-Ser(26).
2. Anthelmintic PF1022A: stepwise solid-phase synthesis of a cyclodepsipeptide containing N-methyl amino acids
Sebastian Lüttenberg, Frank Sondermann, Jürgen Scherkenbeck Tetrahedron. 2012 Feb 25;68(8):2068-2073. doi: 10.1016/j.tet.2011.12.026. Epub 2011 Dec 16.
Cyclodepsipeptides of the enniation-, PF1022-, and verticilide-family represent a diverse class of highly interesting natural products with respect to their manifold biological activities. However, until now no stepwise solid-phase synthesis has been accomplished due to the difficult combination of N-methyl amino acids and hydroxycarboxylic acids. We report here the first stepwise solid-phase synthesis of the anthelmintic cyclooctadepsipeptide PF1022A based on an Fmoc/THP-ether protecting group strategy on Wang-resin. The standard conditions of our synthesis allow an unproblematic adaption to an automated peptide synthesizer.