MOHAMAD M. A. KHEDR* AND HEND M. SABRY
Plant Protection Research Institute, Agricultural Research Center, Giza, Egypt
*(e-mail : m1khedr@yahoo.com; Mobile : +2 01145493942)
(Received : June 11, 2022; Accepted : July 15, 2022)
ABSTRACT
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).
Key words : : Spodoptera littoralis, Ruta angustifolia, larvicidal activity, 2-(2-methoxyphenylethyl)-4Hchromen-4-one, enzymes