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Updated: Feb 12, 2026

Isolation and In vitro Activation of Caenorhabditis elegans Sperm
Published on: January 31, 2011
Synthesis and Complete Structure Determination of a Sperm-Activating and -Attracting Factor Isolated from the
Tomohiro Watanabe1, Hajime Shibata2, Makoto Ebine1
1Faculty and Graduate School of Science , Kyushu University , 744 Motooka , Nishi-ku , Fukuoka 819-0395 , Japan.
Abstract:
For the complete structure elucidation of an endogenous sperm-activating and -attracting factor isolated from eggs of the ascidian Ascidia sydneiensis ( Assydn-SAAF), its two possible diastereomers with respect to C-25 were synthesized. Starting from ergosterol, the characteristic steroid backbone was constructed by using an intramolecular pinacol coupling reaction and stereoselective reduction of a hydroxy ketone as key steps, and the side chain was introduced by Julia-Kocienski olefination. Comparison of the NMR data of the two diastereomers with those of the natural product led to the elucidation of the absolute configuration as 25 S; thus the complete structure was determined and the first synthesis of Assydn-SAAF was achieved.
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