HPLC-DAD and HPLC-ESI-MS analyses of Tiliae flos and its preparations.

tIn the present study extensive HPLC–DAD, HPLC–ESI-MS and NMR analyses were undertaken in theaqueous preparations (decoctions, infusions) and tinctures of Tilia platyphyllos Scop inflorescences. Theaim of this work was to examine in depth the qualitative and quantitative profile of the investigatedpreparations, which find until today wide applications in pharmaceutical and cosmetic industry, and topropose a validated method for their quality control. An HPLC–DAD–ESI-MS method was developed andoptimised for the quantitative determination of the constituents. Marker constituents of Tiliae flos arethe flavonoids, while the volatile content is also used for the quality control. However, the analyses ofthe non-volatile fraction gave complex chromatographic fingerprints containing simple phenolics andlow molecular weight procyanidins. The use of different HPLC columns permitted a good separationof the constituents and enabled their quantitation, while HPLC–MS analyses permitted the detectionof procyanidin oligomers. Overall, 31 constituents were detected and identified. Extensive preparativechromatographic investigations and 2D-NMR analyses allowed the characterisation of procyanidins asepicatechin derivatives. Finally, the HPLC method was validated and complied with ICH guidelines. Thisis the first report of detailed analysis of the chemical composition of Tiliae flos.