High-performance liquid chromatographic, capillary electrophoretic and capillary electrophoretic-electrospray ionisation mass spectrometric analysis of selected alkaloid groups.

Systems for efficient separation of selected alkaloid groups by high performance liquid chromatography (HPLC), capillary electrophoresis (CE) and capillary electrophoresis coupled with electrospray ionisation mass spectrometry (CE-ESI-MS) are described. The optimized HPLC system was applied for the separation of 23 standard indole alkaloids as well as for qualitative and quantitative analyses of crude alkaloid extracts of Rauvolfia serpentina X Rhazya stricta hybrid cell cultures. The developed conditions for CE analysis proved to be efficient for separation of mixtures of standard indole and beta-carboline alkaloids. The described buffer system is also applicable in the combination of CE with electrospray ionisation mass spectrometry. This analytical technique allowed the separation and identification of components of standard indole alkaloid mixture as well as crude extracts of R. serpentina roots, R. serpentina cell suspension cultures and cortex of Aspidosperma quebracho-blanco. The influence of buffer composition and analyte structures on separation is discussed

Qualitative study of yoga for Young adults in school sports.

ObjectivesDistress and stress-related diseases are an increasing public health problem at schools. This qualitative study was nested in a non-randomized, controlled trial studying the effects of a 10-week yoga course as an alternative for regular school sports in two secondary schools in Germany.MethodsWe conducted a qualitative evaluation in 3 focus groups with 6 participants each. The focus groups were audio-recorded, transcribed verbatim, pseudonymised and analysed using qualitative content analysis. Furthermore open questions were asked in questionnaires.ResultsThe analysis of the participants' interviews (mean age 19.6 ± 2.9 years, n = 10 female, n = 8 male) resulted in 4 key topics: 1. encountering yoga, 2. yoga practice, 3. effects and benefits of yoga, and 4. yoga in the school context. Yoga was very well accepted by most participants. They reported a variety of physical and psychological benefits as well as overall restorative effects. The relief of pain or other physical ailments, higher mobility and flexibility, improved posture and improved sleep were mentioned by the participants. Some participants used the new exercises and experiences (e.g. working with the breath) in their everyday life. The possibility for self-responsible action was a welcome change from the perceived pressure and heteronomy in normal (school) life. Controversial was the question of whether yoga - if it is part of school sport - should be assessed or graded, and whether it should be compulsory or voluntary.ConclusionYoga can offer both physical and psychological benefits in young adults as well as offer general regenerative effects. Yoga by sensitizing the participants to negative patterns of behaviour can encourage healthy behaviour

Metagenome Survey of Biofilms in Drinking-Water Networks

Most naturally occurring biofilms contain a vast majority of microorganisms which have not yet been cultured, and therefore we have little information on the genetic information content of these communities. Therefore, we initiated work to characterize the complex metagenome of model drinking water biofilms grown on rubber-coated valves by employing three different strategies. First, a sequence analysis of 650 16S rRNA clones indicated a high diversity within the biofilm communities, with the majority of the microbes being closely related to the Proteobacteria. Only a small fraction of the 16S rRNA sequences were highly similar to rRNA sequences from Actinobacteria, low-G+C gram-positives and the Cytophaga-Flavobacterium-Bacteroides group. Our second strategy included a snapshot genome sequencing approach. Homology searches in public databases with 5,000 random sequence clones from a small insert library resulted in the identification of 2,200 putative protein-coding sequences, of which 1,026 could be classified into functional groups. Similarity analyses indicated that significant fractions of the genes and proteins identified were highly similar to known proteins observed in the genera Rhizobium, Pseudomonas, and Escherichia. Finally, we report 144 kb of DNA sequence information from four selected cosmid clones, of which two formed a 75-kb overlapping contig. The majority of the proteins identified by whole-cosmid sequencing probably originated from microbes closely related to the alpha-, beta-, and gamma-Proteobacteria. The sequence information was used to set up a database containing the phylogenetic and genomic information on this model microbial community. Concerning the potential health risk of the microbial community studied, no DNA or protein sequences directly linked to pathogenic traits were identified

Structures of Alkaloid Biosynthetic Glucosidases Decode Substrate Specificity

Two similar enzymes with different biosynthetic function in one species have evolved to catalyze two distinct reactions. X-ray structures of both enzymes help reveal their most important differences. The Rauvolfia alkaloid biosynthetic network harbors two O-glucosidases: raucaffricine glucosidase (RG), which hydrolyses raucaffricine to an intermediate downstream in the ajmaline pathway, and strictosidine glucosidase (SG), which operates upstream. RG converts strictosidine, the substrate of SG, but SG does not accept raucaffricine. Now elucidation of crystal structures of RG, inactive RG-E186Q mutant, and its complexes with ligands dihydro-raucaffricine and secologanin reveals that it is the "wider gate" of RG that allows strictosidine to enter the catalytic site, whereas the "slot-like" entrance of SG prohibits access by raucaffricine. Trp392 in RG and Trp388 in SG control the gate shape and acceptance of substrates. Ser390 directs the conformation of Trp392. 3D structures, supported by site-directed mutations and kinetic data of RG and SG, provide a structural and catalytic explanation of substrate specificity and deeper insights into O-glucosidase chemistry