Prahl, Fredrick; Hayes, J. M.; Xie, T.-M. (Waco, Tex. : American Society of Limnology and Oceanography, 1992)
The pentacyclic tritcrpene
17β(H), 21β(H)-hop-22(29)-ene (diploptence) occurs
in sediments throughout the Columbia River
drainage basin and off the southern coast of
Washington state in concentrations comparable
to ...