Scilight Press

The present work is the first isolation of a chromone derivative, 2-(2-methoxyphenylethyl)-4H-chromen4-one from the acetonic extract of Ruta angustifolia leaves using thin-layer chromatography and then identified by infrared and mass spectrometry. Results showed that 2-(2-methoxyphenylethyl)-4H-chromen4-one possessed larvicidal activity against the fourth instar larvae of S. littoralis, which fed on treated leaves under laboratory conditions. LC₅₀ values indicated abnormalities in the epithelial cells, muscles and microvilli using a transmission electron microscope in treated compared to untreated larvae. Moreover, a significant reduction was recorded in both the chitinase enzyme and total lipid content compared to the control. Overall the findings of the study suggest that the use of 2-(2-methoxyphenylethyl)-4Hchromen-4-one can act as a new insecticidal agent for controlling the cotton leaf worm (S. littoralis).