Development of assay method of trans-10-hydroxy-2-decenoic acid (10-HDA) in royal jelly and food supplements by high performance thin layer chromatography

Abstract

Introduction. Royal jelly (RJ) is a yellowish-white secretion from the hypofaringeal and mandibular glands of nurse bees. It is a complex compound, which consists of amino acids, carbohydrates, proteins, sugars, lipids, also minerals and vitamins. The unique feature of RJ is fatty acid, (2E)-10-hydroxydec-2-enoic acid (10-HDA). Since only RJ from bee products contains it. Thus, this compound is a biomarker of RJ, and amount of 10-HDA shown the quality of its commercial products. In the past few years, consumption of RJ as a dietary supplement is consistently growing across the world. That’s why the determination of 10-HDA is very important. TLC method was developed to detect the 10-HDA content in royal jelly, lyophilized tablets and capsules. Aim. The aim of this study is to develop method of quantitative and qualitative determination of 10-HDA in fresh royal jelly and in different food supplements, such as lyophilized tablets and capsules, which contains royal jelly. Materials and methods. Standard solution was prepared by diluting of 10-HDA weight in methanol. Test solutions were prepared by using to different techniques. Weight of lyophilized tablets, which contains 70 mg of royal jelly, was sonicated with usage of methanol, as an extractor. The content of capsules, which contains 60 mg of royal jelly, was extracted with a portion of diethyl ether (15 ml), then non-soluble material was extracted with methanol (3x15ml), duration of each extraction was 15 min. Raw material of RJ was extracted using the same method. Extracts were evaporated with liquid nitrogen and were diluted in 1 ml of the same solvent. The separation was performed on silica gel plates (HPTLC Silica gel 60 F254) using a mixture of chloroform: methanol: water (65:35:7) as mobile phase, migration distance was over path of 80 mm. The standard and test samples were spotted in the form of bands of width 6 mm. The determination was performed af [...].