Bioguided fractionation and isolation of phytotoxic compounds from Apium graveolens L. aerial parts (Apiaceae)

The phytotoxic activity of celery (Apiumgraveolens L.)was tested on germination and seedling growth of Lactuca sativa (lettuce). Bioactive compounds were isolated and identified by spectral data. Methanol extract of celery aerial part showed a significant phytotoxic effect on lettuce. Thus, this extract was divided into hexane and methanol fractions. Bioassay-directed of these two fractions led to the isolation and characterization of six secondary metabolites which included three phthalides (senkyunolide A, (3S)-butylphthalide and sedanolide), two furanocoumarins (bergapten and scopoletin) and one phenylpropanoid (p-hydroxyphenethyltransferulate). Among these compounds, senkyunolide Awas themost toxic on lettuce germination and shoot growth. However, p-hydroxyphenethyl trans-ferulate was the most toxic on root growth.