Plant material Plant leaves from L. tomentosa were obtained from Al-Zohiriya garden, Giza, Egypt in May 2011 and authenticated by Department of Botany, National Research Center (NRC) and Consultant of Plant Taxonomy at the Ministry of Agriculture of Orman botanical garden, Giza, Egypt. Leaves from D. virginiana were obtained from the Agricultural Research Center, Giza, Egypt in May 2011 and authenticated by Department of Botany, and NRC.