Dr. Ilse Manet

Current research activity focuses mainly on three topics: non-covalent interactions of biological interest studied with light in substrate-receptor model systems; photophysical and photochemical properties of drugs; photochemical generation of new reactive intermediates of high selectivity.

Non-covalent interactions of biological interest studied in model systems with light. The nature and the strength of non-covalent interactions due to H-bonds, Van der Waals and hydrophobic forces between molecules is at the basis of a large number of phenomena of contemporary interest in chemistry, biology and material science. Understanding of the factors which govern the intermolecular interactions is an important issue. Light is an extremely useful tool not only to get insight into the weak interactions operative in non-covalently linked substrate-receptor systems, but also to track these interactions; Indeed absorption of photons by the ligand or the receptor leads to population of excited electronic states, whose deactivation is extremely sensitive to the environment. The study of the emission of a different photon, transfer of energy/electrons or occurrence of a photoreaction can thus be utilized to study the role of involved in substrate-receptor binding. Both steady-state and pulsed absorption and emission techniques with picosecond-to-second resolution and photochemical methods have been applied to study aromatic molecules and specific drug families, like quinolones and non-steroidal anti-inflammatory drugs (NSAID) either included in cyclodextrin hosts, as model systems, or in proteins like albumins. We have also applied circular dichroism for the study of the stereospecific interactions of drugs with biomacromolecules.

Photophysical and photochemical properties of drugs. Biological photosensitization reactions induced by drugs involve intermediates and photoproducts generated upon light absorption by the drug chromophores. In vivo interaction of these intermediates with cellular components may lead to cell degeneration and/or cell death. Understanding of the role of structural and environmental factors in the photoreactivity of various classes of photoactive drugs is required for their therapeutical applications and for the development of future generations of improved drugs. This matter is also of importance for the practical issue concerning the drug photostability. Photoreactivity of fluoroquinolones and non-steroidal antiinflammatory drugs (NSAIDs) are currently studied by steady state and time resolved photochemical methods.

Photochemical generation of new selective reactive intermediates. In the frame of "green Chemistry" new environmentally friendly synthetic routes are looked for. UV-Vis light is a very attractive source of energy to launch a chemical reaction. It is important to gain knowledge of the photochemically generated intermediates and of their reactivity in order to exploit them adequately. We have carried out laser flash photolysis (lambda-exc. 266 nm) in different experimental conditions with halogenated phenols and anisoles in order to study the reactive intermediates generated and the possibility to capture them with adequate traps thus pushing the reaction is a precise direction.

(Updated 19/01/2009)