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This study was focused on the effects of virus and phytoplasma infections on the production of Echinacea purpurea (L.) Moench secondary metabolites, such as caffeic acid derivatives, alkamides, and essential oil. The identification of caffeic acid derivatives and alkamides was carried out by means of high-performance liquid chromatography-diode array detection (HPLC-DAD), HPLC-electrospray ionization-mass spectrometry (ESI-MS), and MS(2). Quantitative analysis of these compounds was carried out using HPLC-DAD. The results indicated that the presence of the two pathogens significantly decreases (P < 0.05) the content of cichoric acid, the main caffeic acid derivative. Regarding the main alkamide, dodeca-2E,4E,8Z,10E/Z-tetraenoic acid isobutylamide, a significant decrease (P < 0.05) in the content of this secondary metabolite was observed in virus-infected plants in comparison with healthy plants, while in the phytoplasma-infected sample the variation of this secondary metabolite was not appreciable. The % relative area of the E/Z isomers of this alkamide was also found to change in infected samples. The gas chromatography (GC) and GC-MS analysis of E. purpurea essential oil enabled the identification of 30 compounds. The main significant differences (P < 0.05) in the semiquantitative composition were observed for three components: limonene, cis-verbenol, and verbenone. The results indicate that the presence of virus and phytoplasma has an appreciable influence on the content of E. purpurea secondary metabolites, which is an important issue in defining the commercial quality, market value, and therapeutic efficacy of this herbal drug.

Screening and characterization of novel tyrosinase inhibitors is useful for applications in food technology,\ud cosmetics and medicine. The hydrodistilled essential oils from lavender Lavandula spica L. and peppermint Mentha x piperita L.\ud were investigated for tyrosinase inhibitory activity. Their composition was assessed by gas chromatography–mass\ud spectrometry. Both oils inhibited mushroom tyrosinase in a dose dependent manner. The IC50 values were estimated,\ud kinetics were analysed and Ki values were determined. Our results indicate that lavender and peppermint essential oils\ud may be promising herbal ingredients for developing depigmenting agents in clinical, cosmetic and industrial processes

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GC/C/IRMS, in combination with GC/MS and GC/FID, can be considered as an effective and reliable tool for the authenticity control of R. damascena essential oil.

In the present study, a further investigation of the cytotoxic activity of an acetylenic constituent of Echinacea pallida roots, namely, pentadeca-(8 Z,13 Z)-dien-11-yn-2-one, was performed, revealing a concentration-dependent cytotoxicity on several human cancer cell lines, including leukemia (Jurkat and HL-60), breast carcinoma (MCF-7), and melanoma (MeWo) cells. As part of its mechanism of action, the ability of this constituent to arrest the cell cycle in the G1 phase was demonstrated on HL-60 cells. Furthermore, a stability test of the target compound over 72 h was carried out, indicating that the cytotoxic activity can be attributed mainly to the genuine, not oxidized, molecule.

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