Further investigations into abeohyousterone, a new ecdysteroid from the Antarctic tunicate Synoicum adareanum

Five new ecdysteroids were isolated in our laboratory from the Antarctic tunicate Synoicum adareanum. Ecdysteroids are widely known as analogs to the hormone ecdysone, which regulates growth and molting in arthropods [1]. Ecdysteroids function as predator deterrents at low concentration and, as a result, are only produced in trace quantities [2]. Among S. adareanum ecdysteroids, abeohyousterone, hyousterones A-D and diaulusterol B were tested for solid tumor selective cytotoxicity using colon (Colon 38, H-116), lung (H-125M) and leukemia (L1210) cell lines in a soft-agar disk diffusion assay. In the primary assay, abeohyousterone exhibited considerable cytotoxicity against leukemia, Colon 38 and H-116. The initial purification did not result in enough mass to thoroughly study the bioactivity of this compound. Current efforts are aimed at the isolation and purification of further abeoecdysteroids and their analysis in the National Cancer Institute's 60 cell line cytotoxicity panel. Given the broad spectrum of reactivity of ecdysterones, abeohyousterone will be further screened in tropical and infectious disease bioassays.

Acknowledgements: This research was supported financially by grants to BJB (OPP-0125152, OPP-0296207, OPP-0442857) from the National Science Foundation. We thank the American Society of Pharmacognosy for the Undergraduate Research Award to KAW. We would also like to acknowledge L. Cole, Smithsonian Institution, for taxonomic identification of the tunicate. Field and laboratory assistance from C. Amsler, J. McClintock, K. Iken, D. Martin, J. Heimbegner, T. Diyabalanage, K. Peters and M. Amsler is greatly appreciated. Raytheon Polar Services Company and the Antarctic support services of the National Science Foundation provided invaluable logistical support.

References: 1. Goodwin, T.W. et al. (1978) Nature 272:122.

2. Bajguz, A., Dinan, L. (2004) Physiol Plant 121:349–357.