Gemmotherapy represents the most recent therapeutic technique that uses the properties of extracts from fresh meristematic plant tissues, mainly buds and sprouts, by macerating them in ethanol and glycerol. The harvesting time and the location can significantly affect the chemical composition of the buds. Therefore, this work aimed to point out the possible variability in the phenolic content and the antioxidant potential of extracts prepared from commonly grown trees in the Czech Republic. Extracts from buds collected during autumn and spring in three different localities were analysed using UHPLC-MS (ultra-high-pressure liquid chromatography) for the phenols profile. Five tests assays were used for the evaluation of the extract antioxidant potential. The sampling time positively affected the content of total phenols, flavonoids, and phenolic acids. The increased levels of total phenols and flavonoids in localities with high and medium pollution may be the result of the higher levels of NO and SO2, the main air pollutants. However, surprisingly, the content of phenolic acid showed the highest values in the area with the lowest pollution. The results of antioxidant tests did not completely correlate with the levels of phenolic metabolites, which may be due to the involvement of other active molecules (e.g., ascorbate, tocopherol, or proline) in the antioxidant machinery.

• Keywords
• UHPLC-MS (ultra-high-pressure liquid chromatography), antioxidants, gemmotherapy, phenolic acid,
• Publication type
• Journal Article MeSH

Phytochemical investigations of Matricaria chamomilla L. (Asteraceae) stated the presence of several compounds with an established therapeutic and antioxidant potential. The chamomile non-enzymatic antioxidant system includes low molecular mass compounds, mainly polyphenols such as cinnamic, hydroxybenzoic and chlorogenic acids, flavonoids and coumarins. The objective of this work was to evaluate the role of the non-enzymatic antioxidant system after stimulation by ethylene in tetraploid chamomile plants. Seven days of ethylene treatment significantly increased the activity of phenylalanine ammonia-lyase, which influenced the biosynthesis of protective polyphenols in the first step of their biosynthetic pathway. Subsequently, considerable enhanced levels of phenolic metabolites with a substantial antioxidant effect (syringic, vanillic and caffeic acid, 1,5-dicaffeoylquinic acid, quercetin, luteolin, daphnin, and herniarin) were determined by HPLC-DAD-MS. The minimal information on the chlorogenic acids function in chamomile led to the isolation and identification of 5-O-feruloylquinic acid. It is accumulated during normal conditions, but after the excessive effect of abiotic stress, its level significantly decreases and levels of other caffeoylquinic acids enhance. Our results suggest that ethephon may act as a stimulant of the production of pharmaceutically important non-enzymatic antioxidants in chamomile leaves and thus, lead to an overall change in phytochemical content and therapeutic effects of chamomile plants, as well.

• Keywords
• antioxidants, chamomile, chlorogenic acids, ethylene,
• MeSH
• Antioxidants metabolism   MeSH
• Biosynthetic Pathways physiology   MeSH
• Ethylenes metabolism   MeSH
• Phenols metabolism   MeSH
• Phenylalanine Ammonia-Lyase metabolism   MeSH
• Stress, Physiological physiology   MeSH
• Chamomile metabolism   MeSH
• Quinic Acid analogs & derivatives   metabolism   MeSH
• Chlorogenic Acid metabolism   MeSH
• Caffeic Acids metabolism   MeSH
• Plant Leaves metabolism   MeSH
• Matricaria metabolism   MeSH
• Polyphenols metabolism   MeSH
• Plant Extracts metabolism   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Antioxidants MeSH
• caffeic acid MeSH Browser
• caffeoylquinic acid MeSH Browser
• Ethylenes MeSH
• Phenols MeSH
• Phenylalanine Ammonia-Lyase MeSH
• Quinic Acid MeSH
• Chlorogenic Acid MeSH
• Caffeic Acids MeSH
• Polyphenols MeSH
• Plant Extracts MeSH