Natürliche Hemmstoffe von Keimung und Wachstum II Isolierung und Struktur von Hemmstoffen aus , Avena sativa L.+ / Natural Inhibitors of Germination and Growth II Isolation and Structure of Inhibitors from Avena sativa L

Extracts from oat husks which inhibit germination of a variety of seeds were fractionated. After mild alkaline hydrolysis, two active fractions A1 and A2 were obtained. From A1 which contains mainly aliphatic di- and tricarboxylic acids, the inhibitor was isolated by chromatographic procedures and identified as 1,3,4-pentanetricarboxylic acid (11 b) by mass spectrometry. The structure was confirmed by total synthesis of the compound in the form of a mixture of diastereomers 11 a/11 b. From A2, two aromatic compounds were isolated by chromatography and identified by gas chromatography and mass spectrometry as 3,4-dimethoxyacetophenone (12) and dimethoxybutylbenzene. Compounds with similar structures were compared with the natural germination inhibitors with regard to their bioactivity.