Isolated as the sulfate conjugate.
See:
Isolation and Absolute Configuration Determination of Aliphatic Sulfates as the Daphnia Kairomones Inducing Morphological Defense of a PhytoplanktonKo YASUMOTO, Akinori NISHIGAMI, Fumie KASAI, Takenori KUSUMI, and Takashi OOIChem. Pharm. Bull. 54(2) 271-274 (2006)