Matricaria recutita L., German chamomile, is one of the most widely used medicinal plants, whose efficacy has been proven in numerous studies. However, its roots have attracted only little interest so far, since mainly above-ground plant parts are used for medicinal purposes. To broaden the knowledge of chamomile roots, a profound phytochemical characterization was performed along with a bioactivity screening of corresponding root extracts. While volatile constituents such as chamomillol and polyynes were detected using GC-MS, HPLC-MSn analyses revealed the occurrence of four coumarin glycosides, more than ten phenolic acid esters and five glyceroglycolipids. Furthermore, the antioxidant activity of the extracts was evaluated. Polar extracts revealed IC50 values ranging from 13 to 57 µg/mL in the DPPH radical scavenging assay, which is in the same range as reported for chamomile flower extracts. In addition, superoxide radical scavenging potential and mild antibacterial effects against S. aureus und B. subtilis were demonstrated. Moreover, to assess interspecies variation in chamomile roots, extracts of M. recutita were compared to those of M. discoidea DC. Interestingly, the latter revealed stronger antioxidant activity. The presented results aim at the valorization of chamomile roots, previously discarded as by-product of chamomile flower production, as a sustainable source of bioactive phytochemicals.

No abstract

Essential oils are widely used in the food and cosmetics industry as natural flavoring and fragrance substances. For this reason, a thorough quality control applying selected analytical methods is required. Oxidation along with hydroperoxide formation is an important drawback during production and storage of essential oils. Hydroperoxides constitute the main products formed upon photo-oxidation of essential oils. Due to hydroperoxide instability, gas chromatography (GC) and high-performance liquid chromatography (HPLC) analyses are required. According to the European Pharmacopoeia, titration is the official method for oxidation assessment. However, this analysis is time-consuming, and large sample quantities are required. Here, we present a simple and accurate spectrophotometric method for the detection of peroxide trace amounts in essential oils and terpenes. The principle is based on the formation of Wurster’s red, which is enforced by the peroxide-driven oxidation of N,N-dimethyl-p-phenylenediamine dihydrochloride (DMPD). The method was validated using dibenzoyl peroxide (DBP) and cumene hydroperoxide (CHP). To demonstrate the suitability of the method for routine analysis, various oxidized terpenes and essential oils were chosen. Moreover, photo- and thermal oxidation experiments were compared and evaluated using gas chromatography/mass spectrometry (GC/MS) and a synthesized limonene-2-hydroperoxide (Lim-2-OOH) reference standard to gather detailed information on the structural changes of the respective terpenes.

No abstract