Natural Flavins: Occurrence, Role, and Noncanonical Chemistry

Abstract

Flavin-Based Catalysis: Principles and Applications, First Edition. Edited by Radek Cibulka and Marco W. Fraaije.

Site‐Selective Radical Aromatic C−H Functionalization of Alloxazine and Flavin through Ground‐State Single Electron Transfer

“…Bond lengths (CÀ O, CÀ C and CÀ N) and intramolecular distances indicate that both ligands are in catecholate and alloxazine redox states (Scheme 1b and Table S3 for selected values). [44,45] Complex 2 2À • 2TBA + does not lead to observable signals in 1 H NMR spectroscopy, its electronic state was thus studied by Electron Paramagnetic Resonance (EPR) spectroscopy. The X-band EPR spectrum of 2 2À • 2TBA + was measured at room temperature and in frozen CH 2 Cl 2 /CHCl 3 (8 : 2) solution (Figures S22 and S23).…”

“…Flavins (isoalloxazines) are ubiquitous structures for electron transfer, both in biological and synthetic settings. [1] The overwhelming majority of their derivatives are symmetrically substituted by two methyl groups in positions C7 and C8, but with a growing interest in the use of alloxazines and flavins as bioinspired photocatalysts and energy-storage materials, [2,3] efficient methods for their selective functionalization are in high demand (Figure 1). [4] Substitution of the aromatic ring of the (iso)alloxazine core by functional groups such as CF 3 , [5][6][7][8] CO 2 H, [9] or iodine [10] has been shown to tune the redox and photophysical properties of flavins and alloxazines.…”

“…Flavins (isoalloxazines) are ubiquitous structures for electron transfer, both in biological and synthetic settings [1] . The overwhelming majority of their derivatives are symmetrically substituted by two methyl groups in positions C7 and C8, but with a growing interest in the use of alloxazines and flavins as bioinspired photocatalysts and energy‐storage materials, [2,3] efficient methods for their selective functionalization are in high demand (Figure 1).…”

Fine spectral tuning of a flavin-binding fluorescent protein for multicolor imaging

“…Flavins, such as riboflavin (RF, vitamin B2), flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), are ubiquitous biomolecules present in virtually all living cells (1,2). They are often employed as cofactors by so-called flavoproteins, whose genes constitute a notable fraction of all genes found in the genomes of variable organisms (3,4). On their own, flavins display complex photochemistry and photophysics, and have been the focus of numerous studies (5)(6)(7)(8).…”