1379654-63-3Relevant academic research and scientific papers
Isolation, structure determination, and synthesis of allo-RA-V and neo-RA-V, RA-series bicyclic peptides from Rubia cordifolia L.
Hitotsuyanagi, Yukio,Odagiri, Masumi,Kato, Saori,Kusano, Jun-Ichi,Hasuda, Tomoyo,Fukaya, Haruhiko,Takeya, Koichi
, p. 2839 - 2846 (2012/04/04)
Two bicyclic hexapeptides, allo-RA-V (4) and neo-RA-V (5), and one cyclic hexapeptide, O-seco-RA-V (6), were isolated from the roots of Rubia cordifolia L. Their gross structures were elucidated on the basis of spectroscopic analysis and X-ray crystallography of compound 5. The absolute stereochemistry of compounds 4 and 5 were established by their total syntheses, and the absolute stereochemistry of compound 6 by chemical correlation with deoxybouvardin (3). Comparison of the 3D structures of highly active RA-VII (1) with less-active compounds 4 and 5 suggests that the orientation of the Tyr-5 and/or Tyr-6 phenyl rings plays a significant role in their biological activity. The isolation of peptides 4-6, along with compound 3, and the comparison of their structures seem to indicate that peptide 6 may be the common precursor to bicyclic peptides 3-5 in the plant. Allo allo: Two cycloisodityrosine-modified congeners of deoxybouvardin (RA-V) have been isolated from the roots of Rubia cordifolia. Comparison of their structures with that of RA-VII revealed that the orientation of one or both of the Tyr-5 and Tyr-6 phenyl rings plays an essential role in expressing the cytotoxic activity. Copyright
