Rubiyunnanin C

Bioorg Med Chem. 2010 Dec 1;18(23):8226-34.

Rubiyunnanins C-H, cytotoxic cyclic hexapeptides from Rubia yunnanensis inhibiting nitric oxide production and NF-κB activation.[Pubmed: 21044847 ]

Six new (Rubiyunnanin C,rubiyunnanin D, rubiyunnanin E, rubiyunnanin F, rubiyunnanin G, rubiyunnanin H, 1-6) and five known (7-11) cyclic hexapeptides were isolated from the roots of Rubiayunnanensis (Franch.) Diels.
METHODS AND RESULTS:
The structures and stereochemistry of 1-6 were established by extensive spectroscopic analyses and chemical methods. All compounds (1-11) not only exhibited cytotoxic activities against a panel of eleven cancer cell lines with IC₅₀ values ranging from 0.001 to 56.24 μM, but also exerted inhibitory activities against nitric oxide (NO) production in LPS and IFN-γ-induced RAW 264.7 murine macrophages with IC₅₀ values ranging from 0.05 to 12.68 μM.
CONCLUSIONS:
Furthermore, this is the first time it is being reported that compounds 2 and 7-10 significantly inhibited TNF-α-induced NF-κB activation in HEK-293-NF-κB luciferase stable cells with IC₅₀ values of 35.07, 0.03, 1.69, 12.64 and 1.18 μM, respectively.

Zhongguo Zhong Yao Za Zhi. 2012 Sep;37(17):2563-70.

Cyclopeptides from Rubia schumanniana.[Pubmed: 23236752]

To separate and identify cyclopeptides of tubers of Rubia schumanniana.
METHODS AND RESULTS:
The 70% methanol extracts from tubers of Rubia schumanniana were separated and purified by silica gel, RP-18, Sephedax LH-20 and HPLC. Their structures were identified by spectral analysis. Nine cyclopeptides were separated and identified as RA- II (1), RA-V (2), RA-VIII (3), Rubiyunnanin C (4), RA-X (5), RY-II (6), RA- I (7), RA-XIII (8) and RA-XIII-OMe (9), respectively.
CONCLUSIONS:
All of nine cyclopeptides were separated from R. schumanniana for the first time.