The exceptional diversity of the genus Rhododendron has a strong potential for identification, characterization, and production of bioactive lead compounds for health purposes. A particularly relevant field of application is the search for new antibiotics. Here, we present a comparative analysis of nearly 90 Rhododendron species targeted toward the search for such candidate substances. Through a combination of phytochemical profiles with antimicrobial susceptibility and cytotoxicity, complemented by phylogenetic analyses, we identify seven potentially antimicrobial active but non-cytotoxic compounds in terms of mass-to-charge ratios and retention times. Exemplary bioactivity-guided fractionation for a promising Rhododendron species experimentally supports in fact one of these candidate lead compounds. By combining categorical correlation analysis with Boolean operations, we have been able to investigate the origin of bioactive effects in further detail. Intriguingly, we discovered clear indications of systems effects (synergistic interactions and functional redundancies of compounds) in the manifestation of antimicrobial activities in this plant genus.

Background Rhododendron species have been traditionally used in countries like China, Nepal, Russia and North America for treating human diseases. These species are known to be a good source of polyphenolic plant secondary plant metabolites. They are known to have beneficial health properties for humans and have been used to treat diseases like asthma, skin diseases. In this contribution we investigate the phenolic profile and antibacterial activity of extracts from several plant organs including for the first time from leaves of different development stages.MethodsIn this study, the polyphenolic profile of fruits, flowers and leaves of different ages of Rhododendron ambiguum and Rhododendron cinnabarinum were studied by using HPLC–MS and compounds identified based on high resolution masses and identity of tandem mass spectra, UV/VIS spectra and retention times if compared to standards.ResultsFifty-nine different polyphenols including isomers were identified in these species by their fragmentation pattern and high resolution data. Also, the antibacterial activity of these parts (leaves, fruits and flowers) against gram-positive bacteria was studied.ConclusionThe leaves and fruits contained more polyphenols than the flowers. With the exception of flowers, the fruits and leaves of both species were also determined to have a significant antibacterial effect against four gram-positive bacteria.Electronic supplementary materialThe online version of this article (doi:10.1186/s13104-017-2601-1) contains supplementary material, which is available to authorized users.

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It was shown that bioinformatics tools facilitate early stage identification of a biologically active compound(s) using LC-MS data, which reduce complexity and number of separation steps in bioactive screening. Copyright © 2017 John Wiley & Sons, Ltd.

The timing monitoring and control system is a key component for satellite navigation systems. Based on a current clock monitoring and control design, a composite clock concept for clock generation is introduced.In addition to the basic clock correction algorithms in a clock ensemble, also failure scenarios need to be detected and corrective action has to be implemented. With two alternative clock correction algorithms for the clock ensemble, the Kalman filter and the weighted average based NIST AT1 algorithm, this paper will focus on investigation of failure (phase jump, frequency jump and clock failure) detection algorithms and methods for failure correction.As the algorithms are intended to be implemented as part of a satellite payload, the complexity of the algorithms is limited by constraints like limited FPGA size and limited computing power. These constraints will be considered in the evaluation of the failure detection and correction methods.

Yarsagumba (Ophiocordyceps sinensis (Berk.) Sung et al.) is a well-known entomogenous fungus native to alpine nival terrain of trans-Himalaya and Tibetan Plateau. The traditional use of O. sinensis in Ayurvedic medicine as well as in traditional Chinese medicine for range of human health requirements with well documented evidences are themselves testimony of its value. It is regarded as winter worm, summer grass due to its association with Thitarodes (Hepialus) larvae. The extremities of habitat condition and endurance of fungus to sustain adversaries by production of metabolites has led to unique profile of metabolites including nucleosides, proteins and nitrogenous compounds, polysaccharides, sterols, fatty acids and their derivatives, as well as some vitamins and inorganics. There are wide ranges of biological activities that have been reported from O. sinensis including anti-inflammatory, antioxidant, anti-tumor, anti-metastatic, immunomodulatory, antimicrobial, insecticidal, hypolipidaemic, hypoglycemic, antiageing, lipolytic, neuroprotective, renoprotective effects, etc. Although several components can be responsible for activity of compounds, understanding ultimate compounds which fit with biomolecular target is crucial to combat diseases and development of new class of effective drugs. In this review a concise evaluation of pharmacological activities of metabolites reported for O. sinensis are done to provide insight into its biologically active components.