Gas chromatographic-based techniques for the characterization of low molecular weight carbohydrates and phenylalkanoid glycosides of Sedum roseum root supplements.

An extensive characterization of low molecular weight carbohydrates (LMWC) and phenylalkanoid glycosides (PAG) of Sedum roseum root supplements has been carried out for the first time by gas chromatography coupled to mass spectrometry (GC-MS) and by comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC × GC-ToF MS). Optimization of the required derivatization procedure for improved determination of PAG showed the combined use of trimethylsilylimidazole and trimethylchlorosilane as the most appropriate reagents. Up to 37 compounds were qualitative- and quantitatively characterized in different dietary supplements of S. roseum by GC-MS. In addition to the well-known rosin, rosarin, rosavin and salidroside, other carbohydrates, polyalcohols, acids, etc. were determined. Among them, several seven-carbon monosaccharides such as coriose and 2,7-anhydro-β-d-altro-heptulose were detected for the first time in S. roseum root supplements. Sedoheptulose was found to be the most abundant compound (9-151 mg g-1), followed by rosiridin (20-81 mg g-1) and rosavin (11-56 mg g-1). The use of GC × GC-ToF MS allowed the detection and tentative assignation of 48 additional compounds mainly belonging to the phenylalkanoid glycoside, pentosyl-hexose and hexosyl-hexose families.