Michigan State University
Seed oil from Leonotis nepetaefolia contains 16% of laballenic [(-)-5,6-octadecadienoic] acid. This is the first example of a natural C18 allene from higher plants. An anomalous result with periodate-permanganate oxidation was found in which glutaric acid, an expected cleavage product, was not detected. Laballenic acid was very stable to alkali.
Bagby, M. O.; Smith, C. R.; Wolff, I. A.
The Journal of Organic Chemistry