title: Cytotoxic isomalabaricane derivatives and a monocyclic triterpene glycoside from the sponge Rhabdastrella globostellata.
abstract: Seven new isomalabaricane derivatives, rhabdastins A-G (1-7), and a new monocyclic triterpene glycoside, rhabdastoside A (8), have been isolated from the methanol extract of the sponge Rhabdastrella globostellata, collected at Amami-oshima, Japan. Three of them were isolated as their corresponding methyl esters, rhabdastins A-D (1-3). Their structures were determined on the basis of spectroscopic and X-ray diffraction analyses. The isolated compounds were evaluated for their cytotoxicity against the proliferation of promyelocytic leukemia HL-60 cells. Compounds 4, 5, 7, and 11, possessing a cyclopentane side chain, exhibited weak activity, with IC(50) values of 21, 29, 44, and 11 μM, respectively, while compounds 1, 2, and 3, with a 2-substituted-propanoate side chain, were inactive at 100 μM. In addition, the mechanism of cytotoxicity of compounds 4 and 5 was investigated.
authors: Department of Chemistry and Bioscience, Graduate School of Science and Engineering, Kagoshima University, 1-21-35 Korimoto, Kagoshima 890-0065, Japan.
authors: Miyabi
authors: M
authors: Hirashima
authors: Kazuomi
authors: K
authors: Tsuda
authors: Toshiyuki
authors: T
authors: Hamada
authors: Hiroaki
authors: H
authors: Okamura
authors: Tatsuhiko
authors: T
authors: Furukawa
authors: Shin-Ichi
authors: S
authors: Akiyama
authors: Yusuke
authors: Y
authors: Tajitsu
authors: Ryuji
authors: R
authors: Ikeda
authors: Masaharu
authors: M
authors: Komatsu
authors: Matsumi
authors: M
authors: Doe
authors: Yoshiki
authors: Y
authors: Morimoto
authors: Motoo
authors: M
authors: Shiro
authors: Rob W M
authors: RW
authors: van Soest
authors: Kaoru
authors: K
authors: Takemura
authors: Tetsuo
authors: T
authors: Iwagawa
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D018360:Crystallography, X-Ray; D004354:Drug Screening Assays, Antitumor; D006027:Glycosides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D018922:HL-60 Cells; D006801:Humans; D020128:Inhibitory Concentration 50; D015394:Molecular Structure; D011161:Porifera / Q000737:chemistry*; D014315:Triterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*
chemical_list: D000970:Antineoplastic Agents; D006027:Glycosides; D014315:Triterpenes; C552977:rhabdastoside A