Separation and identification of biologically active compounds of the wild plant, Atriplex semibaccata against Aphis craccivora Koch.
Biological and phytochemical studies were conducted on Atriplex semibaccata (collected from different areas in El-Amryea region, Egypt) to investigate the biologically active compounds of this plant against Aphis craccivora. Fraction A with LC50 of 0.036 mg/cm2 and LC95 of 0.096 mg/cm2 was the most effective against Aphis craccivora in comparison to fractions B and C as well as the crude extract itself. The LC50 and LC95 values of the crude extract were 0.057 and 1.523, respectively. The corresponding values for fraction B were 0.047 and 0.161 and for fraction C were 0.04 and 0.097, respectively. These fractions consisted mainly of fatty acids and their esters, terpenes and hydrocarbons. Fraction A, which was the most potent fraction, consisted of fatty acids (32.028%), esters (41%), terpenes (11.977%) and hydrocarbons (6.095%). Fraction C followed fraction A according to the effectiveness against Aphis craccivora. It contained hydrocarbons (24.103%), fatty acids (20.610%), fatty acid esters (24.378%) and terpenes (3.865%). Fraction B had lower toxicity compared with the other 2 fractions, but it was more toxic than the crude extract. It contained 9.535% methyl salicylate and 7.00% phytol in addition to fatty acid esters (6.406%) and high amount of hydrocarbons (53.405%).