Biosynthesis and Inactivation of Ecdysone
Although the fundamental features of the structure and biological function of ecdysone in arthropods have been worked out since its discovery in the early 1930’s, knowledge about metabolism of ecdysone is still rather fragmentary (Horn, 1971). Regarding the biosynthetic pathway of ecdysone, it is known only that ecdysone can be derived from cholesterol or 7-dehydrocholesterol and that α-ecdysone is converted into β-ecdysone. The chemical mechanism for inactivation of ecdysone in vivo is unknown. Also, the site of production of ecdysone in arthropods remains conjectural. Although it has been widely assumed that the ecdysial gland (insect pro-thoracic gland, crustacean Y-organ) manufactures and secretes ecdysone in the manner of a normal endocrine gland, none of the surgical extirpation-replacement experiments done to date with ecdysial glands demonstrate unequivocally that ecdysone is actually produced by this gland (Moriyama et al., 1970).
KeywordsBody Wall Malpighian Tubule Polar Metabolite Sulfate Ester Pyridinium Salt
Unable to display preview. Download preview PDF.
- 1.Heinrich, G. and Hoffmeister, H.: Bildung von Hormonglykosiden als Inaktivierungsmechanismus bei Calliphora erythrocephala. Z. Naturforsch, 25b:358–361, 1970.Google Scholar
- 2.Hoffmeister, H., Rufer, C., and Ammon, H.: Ausscheidung von Ecdyson bei Insekten. Z. Naturforsch, 20b: 130–133, 1965.Google Scholar
- 3.Horn, D. H. S.: The Ecdysones. In: Jacobson and D. G. Crosby (ed.) Naturally Occurring Insecticides, pp. 333–459. New York: Marcel Dekker Inc., 1971.Google Scholar
- 5.King, D.S.: Evidence for Peripheral Conversion of α-Ecdysone to β-Ecdysone in Crustaceans and Insects. Gen. Comp. Endocrinol., 13:512, 1969.Google Scholar
- 6.King, D.S.: Metabolism of α-Ecdysone and Possible Immediate Precursors by Insects in Vivo and in Vitro. Gen. Comp. Endocrinol., in press.Google Scholar
- 7.Moriyama, H., Nakanishi, K., King, D.S., Okauchi, T., Siddall, J. B., and Hafferl, W.: On the Origin and Metabolic Fate of α-Ecdysone in Insects. Gen. Comp. Endocrinol., 13:80–87, 1970.Google Scholar
- 8.Robbins, W. E., Kaplanis, J. N., Thompson, M. J., and Svoboda, J. A.: Chemistry and Biological Activity of the Ecdysones and Ecdysone Analogues. Reported at the Second International Congress of Pesticide Chemistry, Tel Aviv., 1970.Google Scholar
- 9.Siddall, J. B.: Synthetic Studies on Insect Hormones. In: Insect-Plant Interactions. Natl. Acad. Sci., U. S., Work Conference Report, pp. 70–72, 1969.Google Scholar