Isolation and Structural Elucidation of Oenanthe aquatica (L.) Fruit C 15 Polyacetylen Hydrocarbons

From the fruits of Oenanthe aquatica (L.), a plant used in the past in popular medicine, a group of C 15 polyacetylene hydrocarbons have been isolated and structurally identified on the basis of spectroscopic evidence. 2‐ trans ‐9‐ cis ‐2,9‐pentadecadiene‐4,6‐diyne ( 1 ),2‐ trans ‐8‐ cis ‐10‐ trans ‐2,8,10‐pentadecatriene‐4,6‐diyne (2) , and 2‐ trans ‐8‐ trans 10‐ trans ‐2,8,10‐pentadecatriene‐4,6‐diyne ( 3 ) are prominent, while the two other geometrical isomers of 2 and 3 ( 4 and 5 ) exist in small amounts. The results support the generally accepted idea of a parallelism between the biosynthetic pathways of the C 15 and the much more widespread C 17 polyacetylenes.