No abstract

From the fresh leaves or twigs of Aptenia cordifolia, a total of 29 compounds were isolated, including the new tetranoroxyneolignan 18, the new dilignan 19, and the beta-ionone derivative 27, previously only known as a synthetic compound, together with 26 known compounds. The structures of the new products were determined by (1)H-, (13)C-, and 2D-NMR, as well as HR-MS analyses. The phytotoxic effects of the isolates on the germination and growth of the dicotyledon Lactuca sativa L. (lettuce) were studied in the concentration range 10(-4) to 10(-7) M. Several constituents of A. cordifolia were found to be equally active as or superior to 4-hydroxybenzoic acid (HBA) used as positive control.

Seven new cinnamic ester derivatives ( 1- 7) were isolated from a methanol extract of the fresh leaves and twigs of Oxalis pes-caprae (Bermuda buttercup). The structures of these new compounds were determined by spectroscopic data interpretation. The effects of compounds 1- 7 on the germination and growth of Lactuca sativa (lettuce) were studied.

During the screening of Mediterranean invasive plants, Oxalis pes-caprae was identified as promising species. The fresh leaves and twigs of the plant were crumbled and extracted with AcOEt. The solution was concentrated, and separated into acidic and neutral fractions. The crude neutral residue was fractionated by chromatographic procedures, followed by structure elucidation on the basis of 1H- and 13C-NMR, and MS data analysis, and six new phenyl cinnamate derivatives were identified. The phytotoxic effects of the isolated compounds on the germination and growth of the dicotyledon Lactuca sativa L. (lettuce) were studied in the concentration range from 10(-4) to 10(-7) M.