Planta Med 2008; 74 - PG29
DOI: 10.1055/s-0028-1084782

A novel bicyclic hexapeptide from Rubia cordifolia L.: structure, semi-synthesis, and cytotoxicity

K Takeya 1, JE Lee 1, Y Hitotsuyanagi 1, T Hasuda 1, IH Kim 1, T Hasuda 1
  • 1School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432–1 Horinouchi, Hachioji, Tokyo, 192–0392, Japan

Natural antitumour bicyclic hexapeptides, RA-VII (1), RA-V (deoxybouvardin) (3), and their congeners [1], characterized by unique structural features of having a 14-membered strained cycloisodityrosine unit, have attracted considerable attention recently. They are provided with unique biological actions including inhibition of protein synthesis through interaction with eukaryotic ribosomes.

As part of our series of studies on the RA-series peptides from Rubia cordifolia L., the isolation and structure elucidation of a new peptide, RA-XVIII (4) is reported [2]. Semi-syntheses of 4 and its analogues from 3 and 1, and the cytotoxicity of representative analogues of this series against P388 leukemia cells are presented.

References: 1. Cordell (1997) The Alkaloids 49: 301 2. Lee, JE. et al. (2008) Bioorg. Med. Chem. Lett. 18:808.