title: Five new alkaloids from the stem bark of Daphniphyllum macropodum.
abstract: Five new alkaloids, daphnicyclidins M and N (compounds 1 and 2) and calyciphyllines Q-S (compounds 3-5), along with four known ones, paxiphylline C (6), macropodumine B (7), macropodumine C (8) and daphnicyclidin A (9) were isolated from the stem bark of Daphniphyllum macropodum. Calyciphylline Q (3) is the first calyciphylline A derivative possessing a double bond between C-18 and C-19. Their structures and relative configurations were elucidated on the basis of spectroscopic methods, especially 2D NMR techniques. Compounds 1, 2, 8 and 9 exhibited cytotoxic activity against P-388 cells with IC₅₀ values of 5.7, 6.5, 10.3 and 13.8 µM, respectively. Compounds 1 and 2 also showed cytotoxic activity against SGC-7901 cells with IC₅₀ values of 22.4 and 25.6 µM.
authors.affiliation: Department of Pharmacy, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China. luyunyanggq@163.com.
authors.forename: Yunyang
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Department of Pharmacy, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China. gaokai19881220@163.com.
authors.forename: Kai
authors.initials: K
authors.lastname: Gao
authors.affiliation: Department of Pharmacy, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China. steveplum@sina.com.
authors.forename: Xiaoyang
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Pharmacy, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China. zw2214146@163.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Department of Pharmacy, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China. maningtomoto@163.com.
authors.forename: Ning
authors.initials: N
authors.lastname: Ma
authors.affiliation: Department of Pharmacy, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China. tanghaifeng71@163.com.
authors.forename: Haifeng
authors.initials: H
authors.lastname: Tang
mesh_terms: D000470:Alkaloids / Q000737:chemistry* / Q000494:pharmacology* / Q000633:toxicity; D000818:Animals; D045744:Cell Line, Tumor; D006801:Humans; D020128:Inhibitory Concentration 50; D051379:Mice; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D024301:Plant Bark / Q000737:chemistry*; D018547:Plant Stems / Q000737:chemistry*; D064028:Tracheophyta / Q000737:chemistry*
chemical_list: D000470:Alkaloids