ABSTRACT
Hyptis brevipes (Lamiaceae) extracts are shown to exhibit strong insecticidal activity against the 3rd instar larva of the cotton leaf worm Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae), inducing complete larval mortality due to the arrest and/or disruption of metamorphosis. This disruption induced a wide range of abnormalities. The LC50 value of the dichloromethane extract of H. brevipes was 3.0% (95% F.L. = 2.2% - 4.4%; slope = 3.185± 0.952) after three days of treatment. Two active compounds were isolated from the extract following bioassay-guided fractionation and were identified as 5-hydroxy-7,4'-dimethoxy-flavon-3-ol and 5- hydroxy-7-methoxy-2-(4`-methoxy-phenyl)-chromen-4-one based on spectroscopic data. This is the first report of these secondary metabolites in H. brevipes.
ABSTRACT
Bioassay-guided isolation using an in vitro assay testing for anti- schistosomiasis yielded a novel triterpene saponin, asparagalin A, from the n-butanol extract of the roots of Asparagus stipularis Forssk., Asparagaceae. The structure was elucidated by spectroscopic analysis and chemical transformations. Administration of asparagalin A resulted in a retardation of worm growth and locomotion at the first day and showed a significant activity of egg-laying suppression at 200 µg/mL concentration.