Rubipodanin A, the First Natural N-Desmonomethyl Rubiaceae-Type Cyclopeptide from Rubia podantha, Indicating an Important Role of the N9-Methyl Group in the Conformation and Bioactivity

PLoS One. 2015 Dec 22;10(12):e0144950. doi: 10.1371/journal.pone.0144950. eCollection 2015.

Abstract

One new cyclic hexapeptide named rubipodanin A (1), which is the first identified natural N-desmonomethyl Rubiaceae-type cyclopeptide, together with six known Rubiaceae-type cyclopeptides (2-7) were obtained using the TLC cyclopeptide protosite detection method with ninhydrin from the roots and rhizomes of Rubia podantha. The cyclopeptide structures were elucidated by extensive spectroscopic analysis, including 1D-NMR, 2D-NMR, IR, UV and MS. The solution conformation and biological activities of 1 and RA-V (4) were evaluated, and the results demonstrated that the N9-methyl group plays a vital role in the maintenance of the conformation and bioactivity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line
  • Cell Proliferation / drug effects
  • Cell Survival / drug effects
  • HEK293 Cells
  • HeLa Cells
  • Humans
  • Molecular Structure
  • Peptides, Cyclic / chemistry*
  • Peptides, Cyclic / pharmacology
  • Plant Extracts / chemistry*
  • Plant Extracts / pharmacology
  • Plant Roots / chemistry*
  • Rubia / chemistry*

Substances

  • Peptides, Cyclic
  • Plant Extracts

Grants and funding

This work was supported by the National Basic Research Program of China (2013CB127505), the Foundation of Chinese Academy of Sciences (Hundred Talents Program, XDA09030301-4), the National Natural Science Foundation of China (U1032602, 91013002, 31470428), the National New Drug Innovation Major Project of China (2011ZX09307-002-02), and the Natural Science Foundation of Yunnan Province (2012GA003).