title: Novel Nortriterpenes from Phlomis umbrosa.
abstract: We isolated 8 novel 28-noroleanane-derived spirocyclic triterpenoids with unusual skeleton structures, phlomisone (1), phlomistetraol A (2), phlomistetraol B (3), phlomistetraol C (4), phlomispentaol (5), phlomishexaol A (6), phlomishexaol B (7), and phlomisin (8), from the ethanol extract of Phlomis umbrosa rhizomes. Their structures were elucidated on the basis of spectroscopic methods, including 1D, 2D nuclear magnetic resonance (NMR), high-resolution mass spectrometry (HR-MS), and X-ray analyses. Compounds 1-3, 5, and 7 exhibited positive cytotoxic activities against the carcinoma cell lines Hela and L929 in vitro, and these bioactive data suggested that the C-18 and C-21 positions had oxygenated functions that can improve the activity of the compound.
authors.affiliation: School of Pharmaceutical Science, Basic Medical Research Center of Tianjin, Tianjin Medical University, Tianjin, China.
authors.forename: Pu
authors.initials: P
authors.lastname: Liu
authors.forename: Zhi
authors.initials: Z
authors.lastname: Yao
authors.forename: Wen
authors.initials: W
authors.lastname: Zhang
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Takaishi
authors.forename: Hong-Quan
authors.initials: HQ
authors.lastname: Duan
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D045744:Cell Line, Tumor; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D031345:Phlomis / Q000737:chemistry*; D014315:Triterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D014315:Triterpenes; C530547:phlomisone