Isolation of two plasticizers, bis(2-ethylhexyl) terephthalate and bis(2-ethylhexyl) phthalate, from Capparis spinosa L. leaves

Authors: KDIMY, AYOUB - University Of Mississippi; Kim, Seong; ALI, ZULFIQAR - University Of Mississippi; KHAN, MD IMDADUL - University Of Mississippi; TRIPATHI, SIDDARTH - University Of Mississippi; HAJJAJI, SOUAD - Mohammed V University; LE, HOANG - University Of Mississippi

Submitted to: Chemistry and Biodiversity
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/28/2023
Publication Date: 7/28/2023
Citation: Kdimy, A., Kim, S., Ali, Z., Khan, M.H., Tripathi, S.K., Hajjaji, S.E., Le, H.V. 2023. Isolation of two plasticizers, bis(2-ethylhexyl) terephthalate and bis(2-ethylhexyl) phthalate, from Capparis spinosa L. leaves. Chemistry and Biodiversity. https://doi.org/10.1002/cbdv.202300903.
DOI: https://doi.org/10.1002/cbdv.202300903

Interpretive Summary: Capparis spinosa L., commonly known as the caper bush, grows naturally in mountainous regions and it is an important source of food and medicine. Capparis spinosa L. is best known for its edible flower buds (called capers) and fruits, usually salted, pickled, and used as ingredients, seasonings, condiments, or garnishes. As part of the research on bio-guided isolation of active compounds from medicinal plants, we collected C. spinosa L. leaves and buds from two different regions of Morocco, Fez-Meknès and Marrakesh-Safi. While performing bio-guided isolation, 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. DEHT and DEHP are widely used in the petrochemical and polymer industries and belong to a chemical class of phthalic and terephthalic acid esters. These primary plasticizers confer elasticity and flexibility to various fiber and plastic products. This research reports for the first time the isolation of DEHT and DEHP from the leaves of Capparis spinosa L. The study extended to the increase in the detection of plasticizers in our food and medicine sources and the alarming concern about the potential effects of these compounds on human health.

Technical Abstract: 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 the alarming concern about the potential effects of these compounds on human health.