Coordinate and redox interactions of epinephrine with ferric and ferrous iron at physiological pH

Coordinate and redox interactions of epinephrine (Epi) with iron at physiological pH are essential for understanding two very different phenomena - the detrimental effects of chronic stress on the cardiovascular system and the cross-linking of catecholamine-rich biopolymers and frameworks. Here we show that Epi and Fe3+ form stable high-spin complexes in the 1:1 or 3:1 stoichiometry, depending on the Epi/Fe3+ concentration ratio (low or high). Oxygen atoms on the catechol ring represent the sites of coordinate bond formation within physiologically relevant bidentate 1:1 complex. Redox properties of Epi are slightly impacted by Fe3+. On the other hand, Epi and Fe2+ form a complex that acts as a strong reducing agent, which leads to the production of hydrogen peroxide via O-2 reduction, and to a facilitated formation of the Epi-Fe3+ complexes. Epi is not oxidized in this process, i.e. Fe2+ is not an electron shuttle, but the electron donor. Epi-catalyzed oxidation of Fe2+ represents a plausible chemical basis of stress-related damage to heart cells. In addition, our results support the previous findings on the interactions of catecholamine moieties in polymers with iron and provide a novel strategy for improving the efficiency of cross-linking.Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3040

Travel-associated Legionnaires disease in residents from England and Wales travelling to Corfu, Greece, August to October 2011.

Fourteen cases of Legionnaires’ disease were confirmed in residents from England and Wales with history of travel to Corfu, Greece, in the 14 days before symptom onset. These cases were reported to the Health Protection Agency national surveillance scheme for Legionnaires’ disease in residents of England and Wales between August and October 2011. In addition, one case in a Greek national and a case of non-pneumonic legionellosis in a resident from Scotland were also reported. Few cases shared the same accommodation site in Corfu during their incubation period. Epidemiological investigations and microbiological analysis of clinical and environmental samples excluded a single source but rather implicated several accommodation sites as sources of sporadic infection. Control measures have since been implemented at these accommodation sites and no further cases have been reported. This incident highlights the value of epidemiological typing and the importance of effective international response to control and prevent legionella infection