Cytotoxic isomalabaricane derivatives and a monocyclic triterpene glycoside from the sponge Rhabdastrella globostellata.
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.
Hirashima
Miyabi
M
Department of Chemistry and Bioscience, Graduate School of Science and Engineering, Kagoshima University, 1-21-35 Korimoto, Kagoshima 890-0065, Japan.
Tsuda
Kazuomi
K
Hamada
Toshiyuki
T
Okamura
Hiroaki
H
Furukawa
Tatsuhiko
T
Akiyama
Shin-Ichi
S
Tajitsu
Yusuke
Y
Ikeda
Ryuji
R
Komatsu
Masaharu
M
Doe
Matsumi
M
Morimoto
Yoshiki
Y
Shiro
Motoo
M
van Soest
Rob W M
RW
Takemura
Kaoru
K
Iwagawa
Tetsuo
T
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*
D000970:Antineoplastic Agents; D006027:Glycosides; D014315:Triterpenes; C552977:rhabdastoside A