Isolation of Bis(2-Ethylhexyl) Terephthalate and Bis(2-Ethylhexyl) Phthalate from Capparis spinosa L. Leaves

Capparis spinosa L., commonly known as the caper bush, is a spiny shrub known for its edible flower buds and its use as a medicinal plant in traditional medicine. While performing bio-guided isolation of active compounds from Capparis spinosa L. leaves and buds, large amounts of bis(2-ethylhexyl) terephthalate (DEHT, a.k.a. dioctyl terephthalate or DOTP) and bis(2-ethylhexyl) phthalate (DEHP) were isolated from a fraction from the leaf extract that showed antifungal activity against Cryptococcus neoformans. The structures of these two compounds were confirmed by NMR and mass spectroscopic data, which matched with those from the standards that were purchased from Sigma-Aldrich. DEHT and DEHP are phthalic and terephthalic acid esters, the main plasticizers that are used to confer elasticity and flexibility to various fiber and plastic products. This is the first time DEHT and DEHP have been isolated from the leaves of a plant that is as commonly used as Capparis spinosa L. This study adds to the increase in the detection of plasticizers in our food and medicine sources and to the alarming concern about the potential effects of these compounds on human health.