A Novel Sperm-Activating and Attracting Factor from the Ascidian Ascidia sydneiensis

A novel SAAF was isolated from the title ascidian. The structure was elucidated using the entire sample of 4 nmol, suggesting that the position of the OH group confers genus-specificity to sperm chemotaxis in ascidians. This study not only provides insight into the chemical tactics in sperm chemotaxis but demonstrates that the innovative techniques allow structure determination of natural products in trace amounts.