POLYACETYLENES FROM WATER HEMLOCK, CICUTA-VIROSA

Isolation of polyacetylenes from aerial and subterranean parts of wate r hemlock, Cicuta virosa L. (Apiaceae. Apioideae), yielded eleven C-17 -polyacetylenes: cicutoxin (8a), cicutol (3a), (8E,10E)-heptadecadiene -4,6-diyne-1,12-diol (cicudiol, 7), 2,3-dihydrooenanthetol (1) and (8E )-heptadecene-4,6-diyne-1,10-diol (5b) already known to occur in water hemlock, the configurational isomers of cicutoxin (isocicutoxin, 8b) and of cicutol (isocicutol, 3b, and two incompletely characterised iso mers with two cis-double bonds, 3c and 3d), all of them not described in previous investigations, falcarindiol (6), (1,8E,10E)-heptadecatrie ne-4,6-diyn-3-ol (2), already known from other Apiaceae, and the novel polyacetylene (1,8E/Z,10E,12E)-heptadecatetraene-4,6-diyn-3-ol (4a/b) . Keto compounds, postulated to occur in water hemlock, could not be d etected. HPLC profiles of the lipophilic extracts of different organs, individuals, and provenances of water helmock harvested at different seasons revealed quantitative but not qualitative variations of the po lyacetylene composition.