Thermal Destruction of Riboflavin in Different Aggregate States

Hipochromic Effect in Riboflavin Solutions

“…We observed similar concentration quenching of luminescence in binary solvent mixtures for natural dyes. This process is associated with the aggregation of the studied compounds [8][9][10].…”

“…In the process of self-aggregation, depending on the nature of the solvents used, the concentrations of the compounds under study, there is a significant deformation of the electronic spectra of vitamin B 2 and food dyes, in the form of a hypochromic effect [8,10]. Identifying the nature of the hypochromic effect is one of the urgent problems of condensed matter spectroscopy.…”

Synthesis of Riboflavin‐Based Macromolecules through Low ppm ATRP in Aqueous Media

“…The signals were assigned on the basis of 1 H NMR of riboflavin before modification (Figure 2a). Chemical shifts of RF‐Br 2 (Figure 2b): δ (ppm) = 1.81–2.08 ppm (12H, C H 3 –, a), 2.25–2.37 (3H, C H 3 , b), 2.48–2.62 (3H, C H 3 , c), 4.17–4.32 (1H, C H , g), 4.36–4.44 (1H, C H , f), 4.52–4.62 (1H, C H , e), 4.75–5.20 (2H, O H , l), 5.21–5.37 (1H, C H , h), 5.42–5.58 (1H, C H , d), 5.62–5.77 (1H, C H , h'), 6.31–6.52 (1H, C H , d'), 7.65–7.74 (1H, C H , i), 7.86–7.93 (1H, C H , j), and 11.33–11.41 (1H, N H –, k) . In the 1 H NMR spectrum of prepared macroinitiator, new chemical shifts appear at δ = 1.81 to 2.08 ppm (12 H), arising from the methyl protons adjacent to the bromide atom.…”

“…The signals were assigned on the basis of 1 H NMR of riboflavin before modification (Figure 2a). Chemical shifts of RF-Br 2 (Figure 2b) [4,62,63] In the 1 H NMR spectrum of prepared macroinitiator, new chemical shifts appear at δ = 1.81 to 2.08 ppm (12 H), arising from the methyl protons adjacent to the bromide atom. The degree of substitution of the hydroxyl groups in a ribitol side chain of riboflavin was determined by the ratio between the integration areas of the amine proton at the regions of δ = 11.33 to 11.41 ppm (1 H) and the protons of methyl groups of the incorporated bromide structure.…”

Optical Systems for Removal of Polarization Spectra

“…Polarization spectra provide information on the orientation of the molecules of dissolved substances, and also these spectra are more informative with respect to electronic spectra [1]. The photophysical and photochemical properties and processes occurring in solutions of vitamin preparations were studied in [2][3][4][5][6]. Molecules of plant origin have such characteristics that determine their photostability and thermal stability, these characteristics are a guarantee of their use in pharmaceuticals and medicine.…”