Ring Formation and Hydration Effects in Electron Attachment to Misonidazole

• Main Authors: Milan Ončák, Rebecca Meißner, Eugene Arthur-Baidoo, Stephan Denifl, Thomas F. M. Luxford, Andriy Pysanenko, Michal Fárník, Jiří Pinkas, Jaroslav Kočišek
• Format: Article
• Language: English
• Published: MDPI AG 2019-09-01
• Series: International Journal of Molecular Sciences
• Subjects: misonidazole; clusters; low-energy electron; bond formation; electron attachment
• Online Access: https://www.mdpi.com/1422-0067/20/18/4383

We study the reactivity of misonidazole with low-energy electrons in a water environment combining experiment and theoretical modelling. The environment is modelled by sequential hydration of misonidazole clusters in vacuum. The well-defined experimental conditions enable computational modeling of the observed reactions. While the NO<inline-formula> <math display="inline"> <semantics> <msubsup> <mrow></mrow> <mn>2</mn> <mo>&#8722;</mo> </msubsup> </semantics> </math> </inline-formula> dissociative electron attachment channel is suppressed, as also observed previously for other molecules, the OH<inline-formula> <math display="inline"> <semantics> <msup> <mrow></mrow> <mo>&#8722;</mo> </msup> </semantics> </math> </inline-formula> channel remains open. Such behavior is enabled by the high hydration energy of OH<inline-formula> <math display="inline"> <semantics> <msup> <mrow></mrow> <mo>&#8722;</mo> </msup> </semantics> </math> </inline-formula> and ring formation in the neutral radical co-fragment. These observations help to understand the mechanism of bio-reductive drug action. Electron-induced formation of covalent bonds is then important not only for biological processes but may find applications also in technology.