[Dietary supplements as a source of anthocyanins].

Currently, dietary supplements of plant origin based on raw materials containing anthocyanins are widely used. These compounds belong to the class of flavonoids and are glycosides of the flavylic cation. The properties of anthocyanins are associated with their hypolipidemic, hypoglycemic and antioxidant activity. The total content of anthocyanins should be taken into account when developing recipes for dietary supplements. The qualitative composition of individual anthocyanins is an important criterion for the authenticity of this type of product. The purpose of the research was to study anthocyanin content and composition in some dietary supplements that have undergone the procedure of state registration. Material and methods. 34 samples of dietary supplements based on raw materials containing anthocyanins were analyzed. Determination of the total content of anthocyanin pigments was carried out by differential spectrophotometry. The qualitative composition of individual anthocyanins (anthocyanin profile) was determined by reverse-phase HPLC with photometric detection at 510 nm. The peaks of individual compounds were identified by comparing the chromatogram of the sample with experimental and literary data on the order of elution of the most common anthocyanins. Results. The total content of anthocyanins in the analyzed samples varied in a wide range - from 0.013 to 20.8 mg per serving. The study of the anthocyanin profile showed compliance with the declared composition except two samples: in the first, acai extract was used instead of blueberry extract, in the second, black currant extract instead of acai extract. Despite the presence of anthocyanins in the vast majority of dietary supplements studied, only 33% of them can be positioned as sources of anthocyanins. Conclusion. The use of purified extracts with a high content of anthocyanins could solve the problem of low concentration of bioactive compounds in dietary supplements. The conducted research confirms the need for careful monitoring of the content of anthocyanin pigments in products.

[Development and validation of methodology of quantitative determination of sibutramine in dietary supplements by high performance liquid chromatography].

Sibutramine is a highly effective drug for the treatment of obesity. In this regard, unscrupulous manufacturers can add sibutramine as a biologically active synthetic substance prohibited for use in the composition of dietary supplements. Thus, the problem associated with the illegal circulation of such dietary supplements is especially actual, given the scale of the sale of these products. The development and validation of methods for the determination of sibutramine in dietary supplements for slimming (anorexigenic action) for the purpose of quality control in order to ensure the quality of dietary supplements when introduced into civil circulation at customs and on the market. The aim of the study - to develop a method for the quantitative determination of sibutramin in dietary supplements for weight loss by high performance liquid chromatography (HPLC) and to validate it. Material and methods. For the quantitative determination of sibutramine in dietary supplements, we used an Agilent 1100 high performance liquid chromatograph with a UV-detector. The stationary phase was a chromatographic column C18 NUCLEOSIL 4.6×150 mm, particle size 5 µm. The mobile phase contained 0.05 M formate buffer pH 4.0 and acetonitrile in a ratio of 40:60 (by volume). Results and discussion. A methodology has been developed for the determination of sibutramine in dietary supplements for weight loss, which makes it possible to control the quality of dietary supplements. Based on the obtained chromatograms, the specificity was determined; the plant components did not influence the determination of sibutramine in model mixtures. The suitability of the chromatographic system was determined: the retention factor of the compound - 2.222 (more than 2.0), N - 5776 theoretical plates (more than 5000), T peak of sibutramine - 0.939 (not more than 1.5). Within the analytical area of the linearity method: R2=0.9993 (over 0.9950). ε=0.46% (does not exceed 1.5%), the confidence interval includes the value of 100%, the calculated value of the Student's criterion tcalc (2.47) was less than the tabular ttable (2.80), which proved the correctness of the methodology. The precision of the results was determined by the obtained RSD value, which was 0.91% (less than 1%). Limit of detection (LOD) and limit of quantification (LOQ) took values of 0.1 and 1.0%, respectively. The range of measured concentrations was 0.01-20.0 mg/g. Conclusion. As a result of the studies, the method for sibutramine determination in dietary supplements with anorexigenic action was tested and can be used in quality control of dietary supplements.