title: New cytotoxic naphthohydroquinone dimers from Rubia alata.
abstract: Two novel naphthohydroquinone dimers with unprecedented skeletons, rubialatins A (1) and B (2), were isolated from the herbal plant Rubia alata together with their precursor, mollugin (3). The structures were elucidated on the basis of NMR spectra and crystal X-ray diffraction. Compound 1, a racemate, was separated by chiral column chromatography, and the absolute configurations of the enantiomers were determined by the computational methods. Cytotoxicity of 1-3 was evaluated as well as the effect on the NF-κB pathway. Compound (+)-1 showed cytotoxicity and could inhibit NF-κB pathway. Meanwhile, 2 showed cytotoxicity and a synergistic effect with TNF-α on NF-κB activation.
authors.affiliation: State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences , Kunming 650201, China.
authors.forename: Si-Meng
authors.initials: SM
authors.lastname: Zhao
authors.forename: Zhe
authors.initials: Z
authors.lastname: Wang
authors.forename: Guang-Zhi
authors.initials: GZ
authors.lastname: Zeng
authors.forename: Wei-Wu
authors.initials: WW
authors.lastname: Song
authors.forename: Xiao-Qiang
authors.initials: XQ
authors.lastname: Chen
authors.forename: Xiao-Nian
authors.initials: XN
authors.lastname: Li
authors.forename: Ning-Hua
authors.initials: NH
authors.lastname: Tan
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry* / Q000494:pharmacology*; D045744:Cell Line, Tumor; D006801:Humans; D006873:Hydroquinones / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D016328:NF-kappa B / Q000737:chemistry* / Q000187:drug effects*; D010936:Plant Extracts / Q000737:chemistry* / Q000494:pharmacology*; D018517:Plant Roots / Q000737:chemistry*; D011714:Pyrans / Q000737:chemistry* / Q000302:isolation & purification; D045470:Rubia / Q000737:chemistry*; D013237:Stereoisomerism; D014409:Tumor Necrosis Factor-alpha / Q000737:chemistry* / Q000187:drug effects* / Q000378:metabolism; D014961:X-Ray Diffraction
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D006873:Hydroquinones; D016328:NF-kappa B; D010936:Plant Extracts; D011714:Pyrans; D014409:Tumor Necrosis Factor-alpha; C000594801:rubialatin A; C000594803:rubialatin B; C046245:rubimaillin; C063601:1,4-naphthohydroquinone