Erschienen in:
Zeitschrift für Naturforschung C, 45 (1990) 7-8, Seite 835-844
Sprache:
Englisch
DOI:
10.1515/znc-1990-7-815
ISSN:
0939-5075;
1865-7125
Entstehung:
Anmerkungen:
Beschreibung:
Abstract Volatile compounds which are released from fresh leaves of Thuja occidentalis inhibited germination of seeds of Amaranthus caudatus and Lepidium sativum. The volatile compounds were obtained by a vacuum method applied to the leaves, by direct analysis of the content of secretory organs and by solvent extraction of leaves. The bioactive compounds proved to be monoterpenes. The highest bioactivity were found for alcoholic compounds followed by ketones, esters and finally hydrocarbons. Non-volatile germination inhibitors which were ex- tracted with hot water were abscisic acid (3-4 µg/g fresh weight of leaves), and two oxidation products of thujone, 2-[2′-acetyl-l′-isopropyl]cyclopropylacetic acid (“Thujaketosaure”) and 3-isopropyl-5-oxohex-2-enoic acid. These compounds could also be prepared from thujone. The relationship of these compounds with possible allelopathic effects of Thuja occidentalis is discussed.