Planar Chromatography in the Quality Control of Adulterated Citrus paradisi Seed Extract-Containing Products

Summary Grapefruit (Citrus paradisi) seeds are increasingly applied for medicinal purposes, especially due to their antimicrobial and immunostimulant features, to treat or prevent common cold. However, the scientific background of these uses has not been established. To date, only in vitro studies support the antimicrobial effect of the seeds, and there are no data on the systemic antibiotic or other clinical effects. Moreover, recent data refer to the adulteration of grapefruit seed products with synthetic antiseptics which may be an explanation for the antimicrobial efficacy of some formulations. The aim of our study was to develop a simple thin-layer chromatography- based method for the quality control of grapefruit seed extracts. Besides the analytical procedure, we report a quick and simple method for the isolation of limonoids from grapefruit seeds. Limonoids are characteristic compounds of the seeds; hence, the detection of these marker compounds may be the basis of grapefruit identification. Further, a thin-layer chromatographic screening for synthetic antiseptics (quaternary ammonium salts) is also part of the quality control procedure.