title: Three new cytotoxic isomalabaricane triterpenes from the marine sponge Stelletta tenuis.
abstract: Three new isomalabaricane-type triterpenes named stellettins N (1), O (2) and P (3), together with four known compounds (4–7),were isolated from the CCl4 extract of the marine sponge Stelletta tenuis Lindgren. Compound 4 was reported as a natural α-pyrone for the first time, which had been synthesized from gibepyrone B, while 5 was found in the genus Stelletta for the first time. The structures of the new compounds were established on the basis of extensive spectroscopic data analysis including IR, MS, 1D and 2D NMR. The inhibitory activities of compounds 1–3 against three human cancer cell lines (A549, AGS and U-251MG) were evaluated and all the tested compounds exhibited significant cytotoxicity to AGS cells, with IC50 values of 4.52, 9.61 and 7.44 μM, respectively.
authors.affiliation: Institute of Materia Medica, School of Pharmacy, Fourth Military Medical University, Xi'an 710032, PR China; Department of Pharmacy, Xi'an Children's Hospital, Xi'an 710003, PR China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Institute of Materia Medica, School of Pharmacy, Fourth Military Medical University, Xi'an 710032, PR China; Department of Pharmacy, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, PR China. Electronic address: tanghaifeng71@163.com.
authors.forename: Haifeng
authors.initials: H
authors.lastname: Tang
authors.affiliation: Research & Development Center of Biorational Pesticide, College of Plant Protection, Northwest A&F University, Yangling 712100, PR China.
authors.forename: Xiangrong
authors.initials: X
authors.lastname: Tian
authors.affiliation: Department of Pharmacy, Renji Hospital, Affiliated to School of Medicine, Shanghai Jiao-Tong University, Shanghai 200127, PR China. Electronic address: franklin67@126.com.
authors.forename: Houwen
authors.initials: H
authors.lastname: Lin
authors.affiliation: Nuclear Magnetic Resonance Center, Xi'an Modern Chemistry Research Institute, Xi'an 710065, PR China.
authors.forename: Minchang
authors.initials: M
authors.lastname: Wang
authors.affiliation: Department of Pharmacy, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, PR China.
authors.forename: Minna
authors.initials: M
authors.lastname: Yao
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry*; D045744:Cell Line, Tumor; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D015394:Molecular Structure; D011161:Porifera / Q000737:chemistry*; D011753:Pyrones / Q000737:chemistry*; D014315:Triterpenes / Q000737:chemistry*
chemical_list: D000970:Antineoplastic Agents; D011753:Pyrones; D014315:Triterpenes; C000597811:malabaricane
keywords: Cytotoxicity; Isomalabaricane; Marine sponge; Stelletta tenuis