Isolation and Determination of Tocopherols and Tocotrienols from the Seed of Capparis Ovata Grown in Turkey by Reversed-Phase High-Performance Liquid Chromatography

Abstract

Vitamin E is an essential vitamin, consisting of eight organic liposoluble compounds which are tocopherols and tocotrienols. Tocopherols and tocotrienols are collectively named ‘tocols’. Tocols are well-known for their potent biological activities, such as antioxidant, anticancer, anti-aging, anti-inflammatory activities, and they prevent vascular occlusion by providing fluidity in the veins. They are one of the main sources of human nutrition. Therefore, it is vital to analyze various forms of tocols in plants, foods, and other commercial products in addition to monitoring it in body fluids. Capparis Ovata is a plant from the family Capparaceae grown widely in Turkey and has a commercial value. We investigated eight tocols (α, β, δ, γ tocopherols and α, β, δ, γ tocotrienols) in C. Ovata seed; optimized a pressurized liquid extraction (PLE) method for isolation, and developed fully validated RP-HPLC–DAD method. The δ-tocopherol, γ-tocopherol and α-tocopherol quantities were 1505.61 ppm, 930.24 ppm and 47.10 ppm with methanolic PLE method, respectively. All quantities detected with Soxhlet extraction were less than those obtained with PLE. In the present study, δ-tocotrienol was 32 times, γ-tocopherol was 20 times more than α-tocopherol. In consideration of recently reported pharmacological activities of δ- and γ-tocopherols, and the higher effectiveness of δ-tocopherol, our results are of particular importance. We detected and separated all tocols in about 10 min, and β- and γ-isomers of tocopherols had the comparable resolution value of 1.52. The limits of quantification values were low with the range of 0.29 × 10−4 to 9.60 × 10−4 mg mL−1; the recoveries were between 95.84 and 113.83% for all eight tocols, and due to the wide linear quantification ranges, the developed method was stated to be suitable for various amounts of tocol analysis.