Novel cytotoxic polyoxygenated steroids from an Okinawan sponge Dysidea sp.
A library of extracts established from hundreds of marine organisms was screened by a cytotoxicity test. The active organic extract of an Okinawan marine sponge of the genus Dysidea was subjected to bioassay-guided fractionation to give three new polyoxygenated steroids dysideasterols F-H (1-3), together with two known related compounds (4 and 5). Their structures were confirmed by NMR and mass spectroscopic analyses. A characteristic structural feature of 2, 4 and 5 is an allylic epoxide, whereas this epoxide undergoes ring-opening by a neighbouring hydroxyl group to give a tetrahydrofuran ring in 1 and 3. All compounds 1-5 exhibited a similar cytotoxic effect with IC50 values of 0.15-0.3 µM against human epidermoid carcinoma A431 cells, demonstrating that the allylic epoxide moiety was not responsible for this cytotoxic effect.
Graduate School of Bioagricultural Sciences, Nagoya University, Japan.
Sudhakar V S
SV
Govindam
Bong-Keun
BK
Choi
Yukio
Y
Yoshioka
Akihiko
A
Kanamoto
Takeshi
T
Fujiwara
Tetsuji
T
Okamoto
Makoto
M
Ojika
D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D059001:Aquatic Organisms / Q000737:chemistry*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D047088:Dysidea / Q000737:chemistry*; D006801:Humans; D020128:Inhibitory Concentration 50; D007564:Japan; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D013261:Sterols / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology
D000970:Antineoplastic Agents; D013261:Sterols; C575815:dysideasterol F; C575816:dysideasterol G; C575817:dysideasterol H