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A growing world population requires an increase in the quality and quantity of food production. However, field losses due to biotic stresses are currently estimated to be between 10 and 20% worldwide. The risk of resistance and strict pesticide legislation necessitate innovative agronomical practices to adequately protect crops in the future, such as the identification of new substances with novel modes of action. In the present study, liquid chromatography mass spectrometry was used to characterize Rheum rhabarbarum root extracts that were primarily composed of the stilbenes rhaponticin, desoxyrhaponticin, and resveratrol. Minor components were the flavonoids catechin, epicatechin gallate, and procyanidin B1. Specific polyphenolic mixtures inhibited mycelial growth of several phytopathogenic fungi and oomycetes. Foliar spray applications with fractions containing stilbenes and flavonoids inhibited spore germination of powdery mildew in Hordeum vulgare with indications of synergistic interactions. Formulated extracts led to a significant reduction in the incidence of brown rust in Triticum aestivum under field conditions. Arabidopsis thaliana mutant and quantitative reverse-transcription polymerase chain reaction studies suggested that the stilbenes induce salicylic acid-mediated resistance. Thus, the identified substances of Rheum roots represent an excellent source of antifungal agents that can be used in horticulture and agriculture.

Common variations of traditional consecutive infusions of mate (Ilex paraguariensis) tea were studied. Effects of tea grinding type and water temperature on the extraction of volatile and non-volatile compounds were elucidated. Extraction behavior was determined mainly by grinding type and to a minor extent by water temperature. The extraction behavior along the series of infusions is mostly driven by the way the water can access and flow through the tea mass. This processes are impaired by the formation of clogging layers which are more intense upon the increasing abundance of tea particles of sufficiently small size and high water temperatures.

Background Even though allergies are an important health issue, the detected amount of allergen-specific IgE (sIgE) has differed widely between manufacturers in the past, and even as recently as this year. These discrepancies hinder diagnostics and can even impact allergen immunotherapy. Objective The aim of this study was to evaluate the development and status quo of the quality of in vitro diagnostic testing for house dust mites (HDM) and cat epithelium, two important indoor allergen sources. Methods: We analyzed data on the allergen sources European HDM, American HDM and cat epithelium, which were collected by the Society for Promoting Quality Assurance in Medical Laboratories (INSTAND e.V.) during 7 years as part of External Quality Assessment schemes (EQAs). A pseudoanonymized comparison was made of the semi-quantitative data and allergen-class results of the four main suppliers of in vitro diagnostic sIgE tests. Coefficients of variation (CV) were determined in order to evaluate interlaboratory comparability. Results In vitro allergy diagnostic testing for the major allergen sources HDM and cat epithelium still reveals manufacturer-dependent differences. Despite this, there appears to be a cautious trend towards an alignment of the results and interlaboratory comparability with the exception of one supplier. Conclusion Even though these results are promising, future EQAs have to be closely monitored to ensure this positive trend is not just a snapshot.

Background Even though allergies are an important health issue, wide manufacturer-dependent differences in the detected amounts of allergen-specific IgE (sIgE) have repeatedly been found. These discrepancies hinder diagnostics and research into clinically significant cutoff points for life-threatening symptoms. Methods To evaluate whether the reported differences have led to changes in diagnostic testing, we analyzed data from six years of round robin testing (RRT, also known as proficiency testing) at the Gesellschaft zur Förderung der Qualitätssicherung in medizinischen Laboratorien e.V. (Society for Promoting Quality Assurance in medical Laboratories) for the important allergen sources bee venom, wasp venom, and birch pollen. The results of the four main suppliers of in vitro diagnostic sIgE testing were compared in a pseudo-anonymized form using overlay images of box plot graphs for the semiquantitative data and allergen class results. Coefficients of variation (CV) were obtained to study the development of interlaboratory comparability. Results We found that the large differences between the manufacturer collectives remained constant between January 2010 and April 2015 without any real improvement. The CVs were good for two of the four analyzed suppliers, one was marginal and one above the quality level of 20%. Conclusion The numerous publications that have found discrepancies in the sIgE results of the different suppliers did not change the status quo within the last six years. Unfortunately, this is unlikely to change until there is a characterized standard material with known values of sIgE.

A growing world population requires an increase in the quality and quantity of food production. However, field losses due to biotic stresses are currently estimated to be between 10 and 20% worldwide. The risk of resistance and strict pesticide legislation necessitate innovative agronomical practices to adequately protect crops in the future, such as the identification of new substances with novel modes of action. In the present study, liquid chromatography mass spectrometry was used to characterize

New HPTLC (high-performance thin-layer chromatography) methods to evaluate major bioactive compounds in mate (Ilex paraguariensis) tea were developed. Identification of compounds was based on HPTLC-MS (high-performance thin-layer chromatography–mass spectrometry), parallel to other techniques. Quantitative evaluation of the main methylxanthines and phenolic compounds in this species was accomplished by two HPTLC methods which can be performed consecutively on one single plate. A solvent system for the separation of the identified saponins is also described for qualitative evaluations. The methods for quantification were validated in terms of: robustness; LOD and LOQ (limits of detection and quantification); repeatability; intra-day and inter-day variation; ruggedness; and accuracy. The methods have proven to be suitable for evaluation of mate tea aqueous and methanolic extracts, with the advantages of: high-throughput; reduced need of plates and application procedures; and high sensitivity – low LODs and LOQs were achieved. Aqueous extracts of nineteen mate teas of different type, geographical origin and age were evaluated in terms of methylxanthines, phenolic compounds and pH. By means of principal component analysis, distinctive characteristics between mate teas could be observed.

The importance of herbal plants is evident in the prevalent use as flavoring ingredients in food. However, meeting the growing demand for organic grown spices and ‘medicinal plants’ of regional origin is often hampered by technical difficulties during cultivation. Arbuscular mycorrhizal fungi (AMF) can support their host, by helping them to adapt to prevailing local conditions and thus increase the health of the plants. The aim of the present work was to evaluate the effects of arbuscular mycorrhiza (AMF) on the plant’s health, using St. John’s wort (Hypericum perforatum) - Colletotrichum cf. gloeosporioides (Cfg) as the model plant pathosystem. Following inoculation with AMF, the attack of St. John’s wort with Cfg led to a clear reduction in wilting of the two St. John’s wort cultivars. Furthermore, the yield of mycor-rhizal plants increased compared to non-mycorrhizal plants, irrespective of whether they were pathogen-infected or not. Compared to non-mycorrhizal plants, in mycorrhizal plants levels of ascorbic acid were elevated and activity of antioxidant enzymes increased after inoculation with Cfg. Furthermore, in mycorrhizal plants the progress in lipid peroxidation following pathogen attack was reduced, suggesting that the reduction of lipid peroxidation and the induction of antioxidants may play a crucial role in the plant’s defense against Cfg.