Insecticidal effect of polysaccharides extracted from Prunus amygdalus amara’ seeds

Searching natural molecules with insecticidal effects and less harmful to environment is one of scientific and agricultural concern. In this work, the polysaccharidic fraction from Prunus amygdalus amara was tested for its insecticidal potential against Tribolium confusum. Water- soluble polysaccharides of P. amygdalus were extracted at 80°C and filtrated using sevag milieu. Their chemical composition was estimated using FTIR analysis. Contact toxicity and repellent assays were performed by exposing T confusum to different concentrations of the extract, in petri dishes. Levels of malondialdehyde were measured in individuals surviving after 7 days of exposition to 4 mg/ml of PAP. Our results show the richness of PAP in many aromatic and sulfonated compounds that are probably complexed to proteins. The contact toxicity revealed that insects’ mortality was dose and time- dependant. For example, when applied at 8 mg/ml for 15 days, PAPs induced 80 % demise of adult. The repellent effect varied between 66 % and 100 % for the studied doses, after 6 hours of exposition. The analysis of malondialdehyde proved that exposition to PAPs induced oxidative stress at the organismic level, thus explaining in part their toxic effect on T confusum. It is concluded that polysaccharides extracted from P. amygdalus amara exert insecticidal effect against coleopteran and might be considered for the development of new “eco-friendly” insecticides.