Plant-associated bacteria fulfill important functions for plant growth and health. However, our knowledge about the impact of bacterial treatments on the host's microbiome and physiology is limited. The present study was conducted to assess the impact of bacterial inoculants on the microbiome of chamomile plants Chamomilla recutita (L.) Rauschert grown in a field under organic management in Egypt. Chamomile seedlings were inoculated with three indigenous Gram-positive strains (Streptomyces subrutilus Wbn2-11, Bacillus subtilis Co1-6, Paenibacillus polymyxa Mc5Re-14) from Egypt and three European Gram-negative strains (Pseudomonas fluorescens L13-6-12, Stenotrophomonas rhizophila P69, Serratia plymuthica 3Re4-18) already known for their beneficial plant-microbe interaction. Molecular fingerprints of 16S rRNA gene as well as real-time PCR analyses did not show statistically significant differences for all applied bacterial antagonists compared to the control. In contrast, a pyrosequencing analysis of the 16S rRNA gene libraries revealed significant differences in the community structure of bacteria between the treatments. These differences could be clearly shown by a shift within the community structure and corresponding beta-diversity indices. Moreover, B. subtilis Co1-6 and P. polymyxa Mc5Re-14 showed an enhancement of the bioactive secondary metabolite apigenin-7-O-glucoside. This indicates a possible new function of bacterial inoculants: to interact with the plant microbiome as well as to influence the plant metabolome.

These results indicate the suitability of ultrasound-assisted extraction for the extraction of phenolic compounds from Cratoxylum formosum ssp. formosum leaves. This phenolic-enriched extract can be used as valuable antioxidant source for health benefits.

Context: Flavonoids are regarded as essential ingredients for the anti-inflammatory activity of Epilobium angustifolium L. (Onagraceae). The metabolic profiles of medicinal plants vary aside from genetic determination due to the influence by external factors. Objectives: This study evaluates the influence of altitudinal variation on the content of flavonoids in E. angustifolium in two consecutive growing periods. Materials and methods: Aerial and herbaceous plant materials were collected at three different altitudes (800, 1000, and 1500 m) during two collection periods. Plant samples (11-13 samples per altitude and year) were extracted with methanol using accelerated solvent extraction (ASE). Identification and quantification of the constituents were achieved by chromatographic means of HPLC-PDA and LC-PDA-MS analyses. Results: Rising concentrations of flavonol 3-O-glycosides could be detected with increasing altitude. The content of the major compound, quercetin 3-O-glucuronide, ranged from 4.4 ± 2.05 (800 m) to 4.9 ± 1.03 (1000 m) and up to 6.6 ± 1.14 mg/g (1500 m). The total amount of flavonol 3-O-glycosides in 73 analyzed samples ranged from 10.7 ± 1.37 up to 17.3 ± 1.99 mg/g. Discussion: Quercetin-3-O-glucuronide can be considered as a potential marker for the increased production of flavonols in herbal parts of E. angustifolium at higher altitudinal levels. Conclusion: The study confirms that environmental factors at higher altitude result in elevated levels of flavonols in aerial plant tissues of E. angustifolium. Specific factors for influencing the flavonoid content have to be clarified in further studies.

Yu Ping Feng San (YPFS) is a classical TCM formulation which has been traditionally used for treatment of immune system related diseases such as chronic bronchitis, allergic rhinitis and asthma. The formula is a mixture of Radix Saposhnikoviae (Fangfeng), Radix Astragali (Huangqi), and Rhizoma Atractylodis macrocephalae (Baizhu). TLC- and LC-DAD-ESI-MS/MS methods have been developed for the analysis of the metabolic profiles of the single herbs and of the formula. Decoctions and ASE extracts were analyzed in order to trace components of the individual herbs in YPFS. Nine constituents of Radix Saposhnikoviae, ten constituents of Radix Astragali and five constituents of Rhizoma Atractylodis macrocephalae have been assigned in the chemical profiles of the formula, which now allow the standardisation of YPFS. The pharmacological testing showed that all extracts significantly inhibited expression of TNF-α, IFN-γ, and IL-1β in U937 cells, while the inhibition of IL-4 was consistently low. Compared to conventional analyses which are focused on a limited set of compounds, metabolomics approaches, together with novel data processing tools, enable a more holistic comparison of the herbal extracts. In order to identify the constituents which are relevant for the immunomodulatory effects of the formula, metabolomics studies (PCA, OPLS-DA) have been performed using UPLC/QTOF MS data.

Calluna vulgaris (L.) Hull (heather) is the only species within the genus Calluna (Ericaceae). It is a dominant species of heather communities and can be found in most parts of Europe and Northern America from lowland up to alpine regions. Common heather is traditionally used to treat urinary tract disturbances and inflammatory related disorders. This review covers the current knowledge on phytochemical investigations of C. vulgaris which revealed a complex pattern of flavonoid glycosides including acetylated compounds as well as other classes of phenolics (chromones, procyanidins and simple phenols). Recently, an acetophenone (rodiolinozide) was identified. C. vulgaris occurs in habitats comprising several altitudinal zones which makes it an attractive species to study the variation of its metabolic profiles in wild populations growing under different climatic conditions. Within phenolic compounds, flavonols showed significant differences in samples collected at different altitudes with increased levels of quercetin glycosides at higher altitudes whereas no significant correlation could be found for caffeoyl quinic acids and the dihydroflavonol glycoside callunin. Expanding such investigations to different species and different geographical areas should give a more accurate picture of suitable marker compounds within the group of phenolics in order to detect adaptive processes in high altitude plants. Furthermore, investigations on the specific patterns of phenolics at cellular and subcellular level and their variation due to factors like enhanced solar radiation and low temperature should be expanded.