Fe-transferrins or their homologues in ex-vivo mushrooms as identified by ESR spectroscopy and quantum chemical calculations: A full spin-Hamiltonian approach for the ferric sextet state with intermediate zero-field splitting parameters

Electron spin resonance analysis of different mushroom parts and their hydroxyl radical scavenging activities assessed by spin trapping method

“…These results were consistent with the findings of ESR spectroscopy for solid-state mushrooms. We note that the results in this study show no direct relevance to any biological functions due to the transition metal elements in ex vivo mushrooms, although Fe-transferrins or their homologs have been identified by ESR spectroscopy in ex vivo mushrooms, combined with advanced quantum chemical calculations (Nakazawa et al, 2018).…”

“…The spectra consist of four signal components, indicated as P1 to P4. The signal indicated as P2 and appearing around g = 4.0 was attributed to spin-sextet-state Fe 3+ species (Nakazawa et al, 2018). The broad signal around g = 2.2 (P3) with the contribution from hyperfine structures arises from spindoublet Cu 2+ species in relatively high-symmetric (axial) ligand environments.…”

“…We reported that Agrocybe cylindracea, Grifola gargal (Kanno et al, 2013), and Coprinus comatus (Kanno et al, 2020) have antioxidant effects. Nakazawa et al (2018) reported that several mushroom-derived ingredients, which possess antitumor, immunomodulatory, antiviral, and antimicrobial activities, have been isolated and identified, such as phenolic compounds, polysaccharides, peptides, and proteins (Lindequist et al, 2005;Giavasis, 2014;Li and Shah, 2016). These compounds have been characterized using a variety of analytical methods such as gas chromatography (GC), high-performance liquid chromatography (HPLC), and Fourier-transform infrared spectroscopy (FT-IR).…”

“…However, few publications report the use of electron spin resonance (ESR) spectroscopy in characterizing and identifying paramagnetic chemical species such as organic radicals or transition metallocomplexes in mushrooms. ESR studies in the food science research field have been used to study the anti-oxidation behavior of foods and to detect organic radicals produced after food irradiation (Ukai and Shimoyama, 2003;Kikuchi et al, 2011;Akram et al, 2012;Faure and Nystrom, 2016;Hougaard et al, 2016;Nakazawa et al, 2018). Therefore, we analyzed the different parts of mushrooms using ESR to identify radical species in this study.…”

ESR analyses of picket fence MnII and 6th ligand coordinated FeIII porphyrins (S = 5/2) and a CoII(hfac) complex (S = 3/2) with sizable ZFS parameters revisited: a full spin Hamiltonian approach and quantum chemical calculations

“…11 Ferric iron porphyrin complexes are found in hemoglobin and myoglobin, and they are extensively distributed among biological systems as iron carriers such as transferrins. [1][2][3]40,42,50 Iron(III) (3d 5 ) ion can take three spin states, S = 1/2, 3/2 and 5/2 which are changeable with and without the 5th and 6th coordination ligands, for example, oxygen molecule and/or the side chains of amino acids. Spin crossover phenomena between the spin states are phenomenologically triggered by various stimuli such as temperature, pressure, light and so on.…”