Planta Med 2013; 79 - PK17
DOI: 10.1055/s-0033-1348641

Total Synthesis of Marine Cyclopeptide Scytonemin A

J Liu 2, L Wang 2, Z Xu 1, 2, T Ye 1
  • 1Department of Applied Biology & Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
  • 2School of Chemical Biology & Biotechnology, Peking University Shenzhen Graduate School, University Town, Xili, Shenzhen, 518055 China

Scytonemin A, a 34-membered cyclic undecapeptide with potent calcium-antagonistic activity, was isolated from a Scytonema sp. (strain U-3 – 3) by Moore and coworkers in 1988. The structure of the scytonemin A was determined by interpretation of spectral data, chemical degradation, and evaluation of the amino acids obtained by acid hydrolysis. However, the absolute configuration of one of the stereogenic centers presented within the side chain was not assigned. Both scytonemin A and its C-9 epimer were synthesized. The absolute stereochemistry of C9 of scytoenmin A was then assigned by extensive NMR studies of the two synthetic samples. The absolution configuration of scytoenmin A was also confirmed by further Chiral HPLC studies of the two synthetic materials along with the authentic sample. Detailed synthetic studies and stereochemical assignment/confirmation will be presented.