Das Projekt "Endocrine Disruption in Gastropods - Target Identification and Modes of Action" wird vom Umweltbundesamt gefördert und von Universität Frankfurt am Main, Institut für Ökologie, Evolution und Diversität, Abteilung Aquatische Ökotoxikologie durchgeführt. Endocrine disrupting chemicals (EDCs) can affect the hormone system of gastropods at low concentrations causing altered fecundity, feminisation or virilisation. However, ecotoxicological research in this area is hampered by the fact that endocrine pathways and modes of action of potential EDCs in gastropods are poorly understood. The ovoviviparous New Zealand mudsnail Potamopyrgus antipodarum is one of the model species used in this project. In this species effects of EDCs manifest in the reproductive performance of the parthenogenic females i.e. estrogenic substances cause an increase in embryo production. However, it is unclear by which mechanisms or modes of actions these effects are mediated because the target molecules for estrogenic substances (e.g. estrogen receptors) are not sufficiently characterised in P. antipodarum. Another effect of EDCs is the imposex phenomenon in female marine gastropods (e.g. the dogwhelk Nucella lapillus and the netted whelk Nassarius reticulatus). Imposex is characterised by the development of male sex organs (penis and/or vas deferens) additionally to the complete female genital tract, but the underlying mechanism is not fully clarified and a matter of a current scientific debate. Hence, the project aims on the identification and characterisation of possible target molecules for EDCs in P. antipodarumand of modes of imposex induction in N. lapillus and N. reticulatus.
Das Projekt "Untersuchungen zur Wirkungsweise von festen sauren Katalysatoren bei Acylierungen und Cyanierungen von Aromaten" wird vom Umweltbundesamt gefördert und von ACA Institut für Angewandte Chemie Berlin-Adlershof durchgeführt. Ziel des Vorhabens ist die Entwicklung heterogenkatalytischer Verfahren fuer die technische Durchfuehrung elektrophiler Substitutionsreaktionen an Aromaten. Vorrang hat hierbei der Ersatz agressiver Lewis- und Bronstedsaeuren durch saure feste Katalysatoren und damit die Vermeidung von Korrosionen sowie hoher Salzfrachten des Abwassers. Die fuer das Vorhaben ausgewaehlten Reaktionen eroeffnen den Zugang zu hochsubstituierten Zwischenprodukten fuer Wirkstoffe und Funktionsmaterialien. Zur Erreichung der Zielstellung sollen folgende Arbeiten durchgefuehrt werden: - Herstellung der Katalysatoren, beispielsweise von sauren Metallsulfaten, sulfatierten und fluorierten Metalloxiden sowie silicatischer Materialien - Charakterisierung der Katalysatoren - Testung der Katalysatoren, insbesondere fuer die regioselektive Acylierung elektronenreicher Aromaten - Untersuchungen zur Kinetik der Acylierung - Untersuchungen zu Substratstruktur/Reaktivitaetsbeziehungen
Das Projekt "Content, qualitative composition and biological activity of disease-preventive flavonoids and related polyphenolics in selected Chinese vegetables" wird vom Umweltbundesamt gefördert und von Heinrich-Heine-Universität Düsseldorf, Institut für Pharmazeutische Biologie und Biotechnologie durchgeführt. Flavonoids (including flavones, flavonols, catechins, isoflavones, coumestans and anthocyanins) as well as biogenetically related phenylpropanoids of plant origin (e.g. stilbenes or lignans) represent important non-nutritive secondary ingredients of vegetables and fruits. Based on epidemiological studies as well as on numerous in vitro and in vivo experiments flavonoids and other polyphenolic plant constituents are suggested to play a major role in the prevention of important chronic diseases such as cancer that affect large numbers of the human population. This protective action of dietary flavonoids and of related compounds is believed to be mainly due to their anti-oxidative activity involving scavenging of cytotoxic oxygen radicals and to inhibition of specific cancer related targets such as protein kinases and matrix metalloproteinases. For the so called 'phytoestrogens' (isoflavones, coumestans and lignans) another mode of action has been demonstrated: they bind to estrogen receptors and are able to inhibit estrogen-dependent tumor growth. Due to the described importance of flavonoids in the prevention of chronic diseases like cancer a detailed analysis of important modern and traditional Chinese vegetables with regard to their major phenolic constituents will be carried out using modern analytical methods. In addition to the elucidation of individual profiles of plant polyphenolics present in Chinese vegetables special attention will be given to the natural qualitative and quantitative variability of polyphenolic compounds as influenced by environmental factors as well as to their anti-proliferative effects against human cancer cells.