Abstract
An unknown polyacetylene was isolated from the subterranean stems of Solidago altissima L. in which the two polyacetylenes, dehydromatricaria ester (I) and methyl 10-[(Z)-2-methyl-2-butenoyloxy]-(2Z, 8Z)-2, 8-decadiene-4, 6-diynoate (II) had already been found, and its structure was identified as (4Z)-2, 4-decadiene-6, 8-diyn-4-olide (dehydromatricaria lactone) (III). The lactone (III), as well as I, strongly inhibited the growth of the seedlings of barnyard millet (Panicum crus-galli L. var. frumentaceum TRIN.).
The seasonal variations in the polyacetylene contents of the subterranean stems were closely investigated, with the results that III occurred only in the fall of the year while I and II hardly varied throughout the year. II was a major polyacetylene component and the content was 0.9_??_1.0 μmol/g fresh wt.
