Potential use of waste: the phytotoxic activity of the waste and its identified compounds.

The phytotoxic potential of the leaves and twigs of , discarded in the mat-making industry against four test plants (lettuce ( L.), rapeseed ( L.), foxtail fescue ( (L.) C.C. Gmel.) and timothy ( L.)) was investigated and found strong phytotoxic activity. An assay-guided fractionation of extarcts against cress ( L.) through a series of column chromatography steps yielded two compounds, 8-(5-oxo-2,5-dihydrofuran-2-yl) octanoic acid (ODFO) and ()-6-hydroxy-2,6-dimethylocta-2,7-dienoic acid (8-carboxylinalool). ODFO and 8-carboxylinalool showed strong phytotoxic activity against cress and timothy. The concentrations required for 50% growth inhibition ( value) of the seedlings of cress and timothy were 111.94-128.01 and 36.30-91.75 µM, respectively, for ODFO, but the values were much higher at 315.98-379.13 and 107.92-148.41 µM, respectively, for 8-carboxylinalool, indicating the stronger phytotoxic activity of ODFO. This study is the first to isolate ODFO and 8-carboxylinalool from and their phytotoxic potential while ODFO is firstly encountered from any natural source. The growth inhibitory activity of the identified compounds may explain their role in the phytotoxic activity of , which suggests the possible use of its leaves and twigs or its active constituents as natural bioherbicides.