Application of thin layer and column chromatography in monitoring the synthesis of α- tocopheryl-lysine ester

Abstract

Vitamin E comprises of two families of compounds, tocopherols and tocotrienols. It is well known for its antioxidant activity, but recently special attention is paid to the use of vitamin E and its derivatives in the prevention and the treatment of cancer. Various derivatives of vitamin E are synthesized, which exhibit antiproliferative activity. It has been shown that the α-tocopherol ester with the amino acid lysine exhibits improved antiproliferative activity on MCF-7 breast cancer cell line as compared to commercially available preparations. The first stage was the synthesis of α-tocopherol ester with di-Cbz-lysine. Synthesis of ester was monitored by thin layer chromatography (mobile phase: n-hexane-ethyl acetate 3: 1,2 v/v) and the purification of product was done by dry flash column chromatography and by preparative plate chromatography (mobile phase: n-hexane-ethyl acetate 3: 1,2 v/v). In the second stage, Cbz protecting groups were removed by catalytic hydrogenation. The final product α- tocopheryl-lysine ester was detected by TLC (mobile phase: dichloromethane-methanolammonia 9 : 0,9 : 0,1 v/v).

Vitamin E sačinjavaju dve klase jedinjenja, tokoferoli i tokotrienoli. Dobro je poznata njegova antioksidativna aktivnost, a danas se posebna pažnja obraća na upotrebu vitamina E i njegovih derivata u prevenciji i terapiji kancera. Sintetisani su brojni derivati vitamina E koji ispoljavaju antiproliferativnu aktivnost. Pokazano je da estar α-tokoferola sa aminokiselinom lizinom ispoljava bolju antiproliferativnu aktivnost na MCF-7 ćelijskoj liniji karcinoma dojke u odnosu na komercijalno dostupne preparate. U prvoj fazi sintetisan je estar α-tokoferola sa di- Cbz-lizinom. Tok sinteze estra praćen je metodom tankoslojne hromatografije (mobilna faza: nheksan/ etilacetat 3: 1,2 v/v), dok je prečišćavanje proizvoda izvršeno dry flash hromatografijom i preparativnom hromatografijom na ploči (mobilna faza: n-heksan -etil acetat 3: 1,2 v/v). U drugoj fazi katalitičkom hidrogenacijom uklonjene su zaštitne Cbz-grupe sa amino grupa lizina. Finalni proizvod α-tokoferil lizin estar detektovan je primenom TLC metode (mobilna faza: dihlormetan-metanol-amonijak 9 : 0,9 : 0,1 v/v/v).