(7R,8S)-cis-7,8-epoxy-2-methyloctadec-17-ene: a novel trace component from the sex pheromone gland of gypsy moth, Lymantria dispar

Considering the vast Eurasian distribution of gypsy moth, Lymantria dispar (Lepidoptera: Lymantriidae), the many subspecies, and their presence in different lymantriid communities, we tested the hypothesis that L. dispar populations in eastern Asia employ one or more pheromone components in addition to the previously known single component pheromone (7R,8S)-cis-7,8-epoxy-2-methyloctadecane [= (+)-disparlure]. Coupled gas chromatographic–electroantennographic detection (GC–EAD) analyses of pheromone gland extracts of female L. dispar sensu lato (including both AGM and NAGM) on four GC columns (DB-5, DB-23, DB-210, and SP-1000) revealed a new trace component that eluted just before (DB-5; DB-210) or after (DB-23, SP-1000) disparlure, and elicited strong antennal responses. Isolation of this compound by high-performance liquid chromatography and hydrogenation produced disparlure, suggesting that the new component had the molecular skeleton of disparlure, with one or more double bonds. Of all possible monounsaturated cis-7,8-epoxy-2-methyloctadecenes, only cis-7,8-epoxy-2-methyloctadec-17-ene co-chro- matographed with the insect-produced compound on all GC columns and elicited comparable antennal responses. In field experiments in Honshu (Japan) with enantioselectively synthesized compounds, (7R,8S)-cis-7,8-epoxy-2- methyloctadec-17-ene (7R8S-epo-2me-17-ene-18Hy) was weakly attractive to male L. dispar, but was less effective as a trap bait than (+)-disparlure, and failed to enhance attractiveness of (+)-disparlure when tested in blends. The antipode, (7S,8R)-cis-7,8-epoxy-2-methyloctadec-17-ene, was not attractive, and when added to (+)-disparlure and/or 7R8S-epo-2me-17-ene-18Hy reduced attractiveness. Thus, the biological role of 7R8S-epo-2me-17-ene-18Hy remains unclear. It may enhance pheromone attractiveness or specificity in other L. dispar populations within their vast Eurasian distribution.     

A new concept for glycosyltransferase inhibitors: nonionic mimics of the nucleotide donor of the human blood group B galactosyltransferase

Glycosyltransferases play an important role in the formation of oligosaccharides and glycoconjugates. To find suitable and selective inhibitors for this class of enzymes is still challenging. Here, we describe a novel concept that allows the design of inhibitors based on the structure of the donor substrate binding pocket. As a first step we describe the design, synthesis and analysis of inhibitors of the human blood group B galactosyltransferase (GTB). This enzyme served as a model system to study the concept, which can be used for easy access of glycosyltransferase inhibitors in general. In silico docking of bicyclic heteroaromatic ligands to GTB and experimental verification of binding affinities by saturation transfer difference NMR (STD NMR) spectroscopy gave 9-N-pentityl uric acid derivatives as non-ionic mimics of UDP. Two derivatives were synthesized and showed inhibitory activity for GTB as determined by competitive STD NMR experiments and by a radiolabeled enzyme assay.     

Highly dispersed nanosilica-epoxy resins with enhanced mechanical properties

Epoxy-nanocomposite resins filled with 12-nm spherical silica particles were investigated for their thermal and mechanical properties as a function of silica loading. The nanoparticles were easily dispersed with minimal aggregation for loadings up to 25 wt% as determined using transmission electron microscopy (TEM) and ultra-small-angle X-ray scattering (USAXS). A proportional decrease in cure temperatures and glass transition temperature (for loadings of 10 wt% and above) was observed with increased silica loading. The morphology determined by USAXS is consistent with a zone around the silica particles from which neighboring particles are excluded. The “exclusion zone” extends to 10× the particle diameter. For samples with loadings less than 10 wt%, increases of 25% in tensile modulus and 30% in fracture toughness were obtained. More highly loaded samples continued to increase in modulus, but decreased in strength and fracture toughness. Overall, the addition of nanosilica is shown as a promising method for property enhancement of aerospace epoxy composite resins.     

Volatile Exudates from the Oribatid Mite, <Emphasis Type="Italic">Platynothrus peltifer</Emphasis>

Gas chromatographic-mass spectrometric analysis of whole body extracts of Platynothrus peltifer, a desmonomatan oribatid mite that belongs to the family Camisiidae, exhibited a basic profile of seven compounds, comprising the monoterpenes neral, geranial, and nerylformate; the aromatics 3-hydroxybenzene-1,2-dicarbaldehyde (= -acaridial) and 2-formyl3-hydroxybenzyl formate (= rhizoglyphinyl formate), and two unsaturated C₁₇-hydrocarbons, 6,9-heptadecadiene and 8-heptadecene. Neryl formate, -acaridial, and rhizoglyphinyl formate were the main components and amounted to 80% of the extracts. With the exception of -acaridial (relative abundance varied considerably among samples), this chemical profile was consistently present in extracts of P. peltifer from nine different localities in SE-Austria. In addition, two further components, 2,3-dihydroxy benzaldehyde and 7-hydroxyphthalide, both probably of non-oil gland origin, infrequently were detected in the extracts. The aromatic compound rhizoglyphinyl formate, also known from Astigmata, was found for the first time in extracts of Oribatida, whereas all other compounds have already been reported from other oribatid species. The hydrocarbons are generally considered to represent plesiomorphic characters of mite oil gland secretions, whereas the monoterpenes and -acaridial form a part of the so-called astigmatid compounds that are thought to be characteristic for middle-derivative Mixonomata and all more highly derived oribatid groups (including Astigmata).     

Development of a New MnZn-Ferrite Soft Magnetic Material for High Temperature Power Applications

At power electronic applications (e.g. in automotive, lighting, electrical equipment etc.) the inductive components that consist the heart of the power transformers are made of ceramic ferromagnetic materials of the type (Mn_xZn_yFe^{2 +}_{1 – x – y})Fe^{3 +}₂O₄. Usually they are designed in such a way in order to exhibit optimum magnetic performance and electromagnetic power loss minimum at 80–100C, which is the steady state operation temperature region for most devices. However, the continuous miniaturization of electric and electronic equipment associated with a continuous increase in the density of electronic components has as unavoidable consequence the gradual shift of the steady state operation temperature to higher levels. The need is therefore becoming obvious for the development of new power soft magnetic materials optimized to operate at higher temperatures than those at which current existing materials operate. In the present work the development is described of such a new soft ferrite material having the chemical composition (Mn_0.76Zn_0.17Fe^{2 +}_0.07)Fe^{3 +}₂O₄, initial magnetic permeability of 1800 (measured at a frequency f = 10 kHz, an induction level B < 0.1 mT and a temperature T = 25C), Curie temperature of 225C and electromagnetic power losses < 350 mW/cm³ measured at a temperature of 140C, frequency of 100 kHz and a magnetic field strength of 200 mT. The material has been successfully introduced to production and is now commercially available. The largest application is offered by the automotive industry in particular for tackling high temperature operating problems arising when control is being done near the engine (near the engine electronics).     

Disassembly factories for electrical and electronic products to recover resources in product and material cycles

Cycle economy as a paradigm for industry in the 21st century depends on the economical and ecological treatment of limited resources. The objective is to achieve more use with fewer resources to increase the use-productivity of these resources. The European Union, aware of the adverse environmental impacts associated with electrical and electronic consumer goods in particular, has passed legislation regulating their appropriate end-of-life treatment. Adaptation processes, including essential disassembly and re-assembly operations, contribute significantly toward the economical fulfillment of these new legal requirements. Typically, the disassembly of used products is characterized by a high rate of manual operations, wide variety of product types, and unknown product properties. To cope with such demands, life cycle units or product accompanying information systems, are being developed and used for acquiring data about a specific product throughout its life cycle to aid in determining the level of product deterioration. Modular disassembly processes and tools have been developed and realized to enable the handling of multiple productvariants. They are being implemented in prototypical hybrid disassembly systemsfor large- and small-size electrical and electronic consumer goods.