Selection of Crude Solidago virgaurea L. ssp Extracts Based on Two Fast and Efficient Chromatographic Methods (High-Performance Thin-Layer Chromatography or High-Performance Liquid Chromatography) for the Quantification of Total Saponins

摘要

A previous study on Solidago virgaurea extracts showed an inhibiting activity of Candida albicans yeast-hyphal transition due to a mixture of triterpene saponins, leading to applications in the field of oral care products. Such applications require the development of an efficient, fast, and simple quantification method of S. virgaurea total saponins. Two methods were developed: the first was based on high-performance liquid chromatography (HPLC) separation with gradient elution and evaporative light scattering detection (ELSD); the second was based on high-performance thin-layer chromatography (HPTLC) separation with in-situ hydrolysis followed by densitometric measurements at 366 nm. Both calibration curves showed good linear regressions (R-2 > 0.99) within the range of the concentrations tested. The limit of detection (LOD) and the limit of quantitation (LOQ) were 2-4 mu g and 10-16 mu g, respectively. The intra-and inter-day variations were studied and found to remain below 5.6% in terms of relative standard deviation (RSD). The recoveries were 97.02-101.91% with RSD of 0.3-1.96% for spiked sample. Both validated methods were successfully applied to the analysis of total saponins in different S. virgaurea samples. In particular, a harvesting study could be supported by these methods to identify the most relevant vegetal parts to extract, and the locations and vintage to collect, to obtain the desired active saponins. HPLC is the recommended method for precise analyses, but HPTLC is the most efficient for the fast analysis of multiple samples.