Abstract:
This paper describes the preparation of plant extracts using
solid-liquid ultrasonic extraction (sonoextraction), the characterization of
prepared extracts and their bioinsecticidal activity. The studied raw vegetal
material:Primula veris, Achillea millefolium, Origanum vulgare and Artemisia
absinthium, was collected from the spontaneous flora of Romania, Moldova
region. To assess the efficiency of solid-liquid sonoextraction process, the
influence of some operating parameters such as solid/liquid ratio, extraction
time, extraction temperature, and extraction efficiency was studied. The
qualitative study has in view the interpretation of UV-VIS spectra recorded for
the extracts, and the quantitative study consists in the estimation of total
polyphenols and flavonoids content of prepared vegetal extracts. The resulted
data indicate that the content of polyphenols and flavonoids is dependent of
the extraction temperature, extraction time and solid/liquid extraction ratio.
The bioinsecticidal activity of Origanum vulgare and Artemisia absinthium
extracts was evaluated on the Acanthoscelides obtectus (commonly named
as ladybug bean) using two application techniques (i.e. direct and indirect
application using a cellulose disk as a porous material impregnated with
extract that allows controlled evaporation), being registered a mortality rate
of adults in the range of 35-55%. Therefore, the studied extracts proved to
be effective in controlling ladybug bean from seed stores.
