Accumulation of coumarin-related compounds in leaves of Matricaria chamomilla related to sample processing

This experiment was carried out to study the influence of sample processing on the quantitative changes of the main coumarin derivative in the leaves of Matricaria chamomilla – herniarin and its glucosidic precursors [(Z)- and (E)-2-β-d-glucopyranosyloxy-4-methoxycinnamic acids (GMCAs)]. Fresh and air-dried, as well as heat-dried samples (80, 100 and 120 °C), from four week-old plants were analysed. The content of Z-GMCA was the lowest in fresh samples while the content of herniarin was the highest in fresh samples. E-GMCA was not affected by sample processing. The E/Z-GMCA ratio decreased from fresh to heat-dried samples. The ratio of herniarin/Z-GMCA displayed the same trend. Probable mechanisms of these changes are also considered. The sum of GMCAs and herniarin, calculated as μmol g−1 DW, did not change significantly among all tested variants, to support our assumption that herniarin is not a volatile coumarin derivative.