Karin Winkler

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Parasitoids as well as many of their herbivorous hosts, depend on carbohydrate-rich food during the adult stage. Different types of nectar and honeydew vary with regard to their sugar composition. In order to successfully exploit a food source, the insect must show a positive gustatory response to its component sugars and be able to digest and metabolise(More)
Mistletoe (Viscum album L.) contains the triterpene acids oleanolic acid (OA) and betulinic acid (BA), which were found to have anti-tumour properties. In this study, the solubilities of OA and BA were studied in water (up to 0.02 microg/mL in each case) and in alkaline solutions of 10 mM trisodium phosphate (pH 11.5; OA: 77.2 microg/mL; BA: 40.1(More)
Membrane interactions of liposomes of ternary phospholipid/cholesterol bilayers are investigated. These interactions lead to discoidal deformations and regular aggregations and are strongly enhanced by the presence of mistletoe lectin (ML), a RIP II type protein. The encapsulation of ML into liposomal nanocapsules is studied with a systematic variation of(More)
The dynamic surface elasticity and the surface dilational viscosity of three binary phospholipid/cholesterol mixtures were determined with axisymmetric drop shape analysis on a harmonically oscillating pendent drop. Dipalmitoylphosphatidylcholine, dimyristoylphosphatidylcholine, and dioleoylphosphatidylcholine were used to explore the rheological properties(More)
Extracts of Viscum album L. produced by a specific homogenization procedure contain viscotoxins (VT) and liposome-like membrane vesicles, formed from cellular membranes. Interactions between these membrane structures and viscotoxins are characterized in this work. Binding properties of viscotoxins with mistletoe extracts or isolated membrane vesicles were(More)
During the preparation of plant extracts by a press-slit technique, membranes of cell walls and cell organelles of the plant material form vesicles, which are colloidally dispersed. It was assumed that chlorophyll-containing green extracts enclose lipoidic structures. Vesicles in aqueous mistletoe extracts (extracts of Viscum album L.) were analyzed by(More)
The use of flowering field margins is often proposed as a method to support biological control in agro-ecosystems. In addition to beneficial insects, many herbivores depend on floral food as well. The indiscriminate use of flowering species in field margins can therefore lead to higher pest numbers. Based on results from field observations and laboratory(More)