Quantitative determination of phenolic compounds in artichoke-based dietary supplements and pharmaceuticals by high-performance liquid chromatography.

Dietary supplements are among the most rapidly growing products in the food and personal care market with an estimated worldwide volume exceeding $60 billion. The main problem associated with dietary supplements is their legal classification. Being neither food nor medicine, they often inhabit a gray area between the two, which makes legal regulatory extremely difficult. Thus, a coexistence of products processed from the same botanical source on the same market as dietary supplement or pharmaceutical is possible. In the present study, various artichoke-based dietary supplements were investigated for their phenolic profile and compared to artichoke phytopharmaceuticals. Quantification of individual hydroxycinnamic acids and flavonoids was carried out by external calibration. For the first time, determination of several apigenin derivatives was included. Chlorogenic acid represented the major constituent in all samples investigated with the exception of juice derived from fresh flower heads, which exhibited a higher cynarin content. Furthermore, a distinction between products made from artichoke leaves or flower heads was possible. The results obtained revealed great diversity of pharmaceuticals and dietary supplements, highlighting the need of standardized quality requirements.