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As an essential vitamin, the role of riboflavin in human diet and health is increasingly being highlighted. Insufficient dietary intake of riboflavin is often reported in nutritional surveys and population studies, even in non-developing countries with abundant sources of riboflavin-rich dietary products. A latent subclinical riboflavin deficiency can result in a significant clinical phenotype when combined with inborn genetic disturbances or environmental and physiological factors like infections, exercise, diet, aging and pregnancy. Riboflavin, and more importantly its derivatives, flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), play a crucial role in essential cellular processes including mitochondrial energy metabolism, stress responses, vitamin and cofactor biogenesis, where they function as cofactors to ensure the catalytic activity and folding/stability of flavoenzymes. Numerous inborn errors of flavin metabolism and flavoenzyme function have been described, and supplementation with riboflavin has in many cases been shown to be lifesaving or to mitigate symptoms. This review discusses the environmental, physiological and genetic factors that affect cellular riboflavin status. We describe the crucial role of riboflavin for general human health, and the clear benefits of riboflavin treatment in patients with inborn errors of metabolism.

Understanding molecular recognition is of fundamental importance in applications such as therapeutics, chemical catalysis and sensor design. The most common recognition motifs involve biological macromolecules such as antibodies and aptamers. The key to biorecognition consists of a unique three-dimensional structure formed by a folded and constrained bioheteropolymer that creates a binding pocket, or an interface, able to recognize a specific molecule. Here, we show that synthetic heteropolymers, once constrained onto a single-walled carbon nanotube by chemical adsorption, also form a new corona phase that exhibits highly selective recognition for specific molecules. To prove the generality of this phenomenon, we report three examples of heteropolymer–nanotube recognition complexes for riboflavin, L -thyroxine and oestradiol. In each case, the recognition was predicted using a two-dimensional thermodynamic model of surface interactions in which the dissociation constants can be tuned by perturbing the chemical structure of the heteropolymer. Moreover, these complexes can be used as new types of spatiotemporal sensors based on modulation of the carbon nanotube photoemission in the near-infrared, as we show by tracking riboflavin diffusion in murine macrophages. Synthetic polymers form highly selective molecular recognition motifs for biomolecules on adsorption onto single-walled carbon nanotubes.

The activity of cytochrome P450 enzymes decreases in older adults, which can lead to toxic effects from polypharmacy. Cytochromes P450 are the most significant enzymes involved in the metabolism of foreign compounds, including pharmaceutical substances. Vitamin B2, or riboflavin (RF), is a potent antioxidant that is vital for the body and participates in numerous enzyme-catalyzed redox reactions. RF is phosphorylated intracellularly to form flavin mononucleotide (FMN), which is further metabolized into flavin adenine dinucleotide (FAD). The active site of the NADPH-dependent cytochrome P450 reductase (CPR), a redox partner of CYP enzymes, is necessary for the catalytic functions of cytochromes P450. The active site of reductase is a complex formed by two types of vitamin B2, such as flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN). In our study, we investigated the impact of the phosphorylated form of vitamin B2, FAD, and FMN on the catalytic activity of cytochrome P450 2C9 (CYP2C9) towards non-steroidal anti-inflammatory medications diclofenac and naproxen. It was shown that FAD significantly enhanced the catalytic efficiency of CYP2C9. The 4-hydroxylation of diclofenac was enhanced by 148 ± 10%. The O-demethylation of naproxen showed an increase of 120 ± 14%. Based on these data, we can assume that intake of vitamin B2 (riboflavin) improves catalytic efficiency of CYP2C9. This finding is essential for the modulation of catalytic activity of CYP2C9. The proposed electroanalytic approach is a sensitive and robust method for drug metabolism assay.

A new coordination polymer (CP) based on Co(II), namely, {[Co 3 (L) 2 (4,4′-bipy)(DMA) 2 ]·H 2 O} n  ( 1 ) has been synthesized after reacting Co(NO 3 ) 2 ·6H 2 O with H 3 L ligand in the existence of N-donor ligand 4,4′-bipyridine (4,4′-bipy), via utilizing a flexible tricarboxylic acid ligand 5-((formic acid-3-sulfur)methyl)isophthalic acid (H 3 L) with –S-CH 2 - joint. Additionally, the excellent blue fluorescence properties of CP 1 were confirmed through fluorescence spectroscopy compared to the original ligand. Using natural polysaccharide hyaluronic acid (HA) and carboxymethyl chitosan (CMCS) as raw materials, HA/CMCS hydrogel was prepared by chemical synthesis method. Taking vitamin B2 as the drug model, we designed and synthesized gels loaded with vitamin B2 metal framework and evaluated their efficacy in the treatment of recurrent oral ulcer.

The treatment of several pediatric metabolic diseases involves vitamins supplementation. Among these, thiamine, riboflavin, pyridoxine and biotin can be prescribed and compounded as hard gelatin capsules. In compounding practice, a medication can be done extemporaneously, leading to a risk of error. However, a medication can also be done in advance, analytically controlled and stored. Such practice reduce the risk of error and decrease the cost, but also imposes the realization of stability studies to establish beyond-use-dates. Thiamine hydrochloride, riboflavin, pyridoxine hydrochloride, and biotin hard gelatin capsules chromatographic and microbiological methods were both validated and used to perform stability studies. Thiamine hydrochloride 50 mg hard gelatin capsules with microcrystalline cellulose and silica as excipients are stable for 6 months when stored at 25 ° C/ 60% RH protected from light. Riboflavin 50 mg with microcrystalline cellulose, pyridoxine hydrochloride 50 mg with microcrystalline cellulose and biotin 40 mg with microcrystalline cellulose/silica are stable for one year when stored at 25 ° C/ 60% RH protected from light. These results allow the compounding in advance of batches of 300 capsules controlled, stored, and quickly dispensed in case of an emergency, such decreasing the risk of error and/or iatrogenic event.

Alginates derived from macroalgae have been widely used in a variety of applications due to their stability, biodegradability and biocompatibility. Alginate was extracted from Egyptian Sargassum latifolium thallus yielding 17.5% w/w. The chemical composition of S. latifolium is rich in total sugars (41.08%) and uronic acids (47.4%); while, proteins, lipids and sulfates contents are 4.61, 1.13 and 0.09%, respectively. NMR, FTIR and TGA analyses were also performed. Crystallinity index (0.334) indicates alginate semicrystalline nature. Sodium alginate hydrolysate was evaluated as Chlorella vulgaris growth promoter. The highest stimulation (0.7 g/L biomass) was achieved by using 0.3 g/L alginate hydrolysate supplementation. The highest total soluble proteins and total carbohydrates were 179.22 mg/g dry wt and 620.33 mg/g dry wt, respectively. The highest total phenolics content (27.697 mg/g dry wt.), guaiacol peroxidase activity (2.899 µmol min −1  g −1 ) were recorded also to 0.3 g/L alginate hydrolysate supplementation. Riboflavin-entrapped barium alginate-Arabic gum polymeric matrix (beads) was formulated to achieve 89.15% optimum drug entrapment efficiency (EE%). All formulations exhibited prolonged riboflavin release over 120 min in simulated gastric fluid, followed Higuchi model (R 2  = 0.962–0.887) and Korsmeyer–Peppas model with Fickian release (n ranges from 0.204 to 0.3885).

This study reports the development of chitosan-based (CS) films incorporating riboflavin (RF) as a natural photosensitizer to create sustainable, light-activated antimicrobial packaging materials. The films were prepared by solvent casting, and their photochemical behavior under blue LED light (450 nm) was investigated, including RF photodegradation kinetics and structural changes in the film-forming solution analyzed by 1H NMR spectroscopy. Mechanical, thermal, optical, and barrier properties were also characterized to assess packaging suitability. Upon illumination, CS/RF films generated reactive oxygen species, particularly singlet oxygen (1O2), leading to visible color changes and significant antimicrobial activity against Pseudomonas fluorescens. Bacterial growth was reduced by up to 97% after 120 min of irradiation (0.92 J cm−2), with efficacy observed at both room temperature and 4 °C. The incorporation of RF did not alter the films’ mechanical properties, while thermal stability was preserved, optical transparency was modulated, and excellent oxygen barrier performance was maintained, although water vapor permeability remained moderate. These findings demonstrate that CS/RF films combine functionality and sustainability, offering a promising strategy for extending food shelf life through light-activated antimicrobial action. Validation under real storage conditions is recommended to confirm their potential in diverse food systems.

In this study, an electrochemical sensor based on a poly(resorcinol) modified carbon nanotube paste electrode (P(RS)/MCNTPE) was successfully developed for the sensitive and selective detection of uric acid (UA) in the presence of dopamine (DA) and riboflavin (RFN). The sensor shows excellent performance in a 0.2 M phosphate buffer solution (PBS) at pH 7.0 with a scan rate 0.1 V/s. Various electrochemical methods were studied including cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). Morphological analysis using scanning electron microscopy (SEM) conformed the enhanced surface properties of the bare carbon nanotubes paste electrode (BCNTPE) and the P(RS)/MCNTPE. The effect of pH, scan rate changes 0.025 to 0.25 V/s, revealed that the oxidation of UA follows an adsorption-controlled process. For UA concentration changes from 20 µM and 380 µM, sensor exhibited a limit of detection (LOD) of 0.18 µM and a limit of quantification (LOQ) of 0.61 µM. Optimal UA response was observed at pH 7.0. The sensor shows good stability, repeatability, and reproducibility. Its analytical applicability was successfully validated in real sample analysis.

Singlet oxygen is a type of reactive oxygen species that is typically generated via type II photosensitization reactions. Since 1,3-diphenylisobenzofuran (DPBF), a commonly used chromogenic probe, exhibits peak absorbance at 410 nm for singlet oxygen detection, it severely interferes with blue light irradiation and compounds that absorb in this wavelength region. This study investigated developing and validating a fluorescence-based method using DPBF to quantitatively analyze the type II photosensitizing property of riboflavin (RF) and its heterocyclic flavin derivatives. DPBF fluorescence-based analysis provided more sensitive and practical results than traditional colorimetric methods. It effectively overcomes spectral interference from colored photosensitizers, such as RF and its derivatives, under blue light irradiation (λ peak 447 nm). This method permitted more effective measurement of their activity without interference from their intrinsic color and maintained high linearity and low variation across different sample concentrations, even with short irradiation times. The type II photosensitizing potency of the tested compounds under blue light was consistently ranked as follows: RF > flavin mononucleotide > flavin adenine dinucleotide > lumiflavin > lumichrome. The results suggest that the DPBF fluorescence-based assay is a more effective approach than colorimetric analysis, making it a practical and reproducible tool for assessing the type II photosensitizing properties of diverse compounds. This study also provides a refinement of an existing probe-based assay for relative comparisons under visible light conditions.

Riboflavin (RF) was considered to be possessed of photoactivity to generate reactive oxygen species (ROS) under ultraviolet (UV) light, which is thought to be a favorable antibacterial candidate. Herein, RF was incorporated into chitosan (CS) coatings and treated under UV with different exposure times (2, 4, and 6 h) to improve the physicochemical and antibacterial properties. The results showed that the light transmittance and antibacterial performance of chitosan coatings gradually increased with the extension of the UV irradiation time. The antibacterial ability of chitosan coatings correlated with the generation of ROS: ∙OH and H2O2, which achieved 1549.08 and 95.48 μg/g, respectively, after 6 h irradiation. Furthermore, the chitosan coatings with UV irradiation also reduced the pH value, total volatile basic nitrogen (TVB-N), ΔE, and total viable counts (TVC) and improved sensory attributes of pork. In conclusion, the UV irradiated chitosan coatings could be used as an environmentally friendly antimicrobial packaging material to effectively delay the spoilage of pork, maintain its sensory quality and prolong its shelf life.