A Relationship Between Cytotoxicity, Antioxidant Activity and Seasonal Changes in Glucosinolates and Isothiocyanate in Kale Varieties Recently Cultivated in Egypt

El-gengaihi, Souad E.; Aboubaker, Doha H.; Amer, Heba M.; Abdelhamid, Sayeda A.; Asker, Mohsen S.; Riad, Gamal S.; Mohammed, Mona A.

doi:10.21608/ejchem.2024.283173.9598

A Relationship Between Cytotoxicity, Antioxidant Activity and Seasonal Changes in Glucosinolates and Isothiocyanate in Kale Varieties Recently Cultivated in Egypt

Document Type : Original Article

Authors

¹ Medicinal & Aromatic Plants Research Dept., National Research Centre, Dokki, 12622, Cairo, Egypt

² Microbial Biotechnology Dept., National Research Centre, Dokki, 12622, Cairo, Egypt

³ Vegetables Crop Dept., National Research Centre, Dokki, 12622, Cairo, Egypt

10.21608/ejchem.2024.283173.9598

Abstract

The kale plant, an important member of the family Brassicaceae, was recently introduced to Egypt. Five varieties of kale were propagated in two growing seasons: winter and autumn. They have successfully grown and will continue their growth to maturity. The first season propagated in sandy soil (SS) was taken in July 2022, while the second season cut in clay soil (CS) took place in January 2023. The plant is consumed due to its high content of health-promoting glucosinolates (GS), and its hydrolysable product, isothiocyanate (ITC), is an important antitumor agent. These two substances were spectrophotometrically determined through different developmental growth stages. The yield of leaves differs between the varieties studied, which all increased gradually until they reached their maximum at the cutting stages. The prumier type produced a higher yield in the two cuttings and was higher in the second one due to the soil type propagated, which is clay in texture. Also, kale varieties differ in their content of GS and ITC. A multi-purpose chromatographic technique was used for analysis, where glucosinolates and isothiocyanates were separated simultaneously by heat and enzyme method, with the measure by spectrophotometer at 320 nm for isothiocyanate from K4: Lacinato, giving 1.67 ± 0.10 ug/g in June by dichloromethane extract, and 425 nm for glucosinolates, giving 118.92 ± 0.34 ug/g in sandy soil compared to enzyme methods, giving 17.85 ± 1.53 ug/g isothiocyanates. In conclusion, the HPLC was giving the highest sulfuraphane concentration in K1: Vates Blue Curled at January in the second season as 163.84 ug/g.

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