The interaction amid Monascus pigment (MP) and ovalbumin (OVA) was studied using multispectral and computer simulations. The fluorescence results demonstrated that MP could effectively quench the fluorescence emission of OVA. According to Stern-Volmer and the double logarithmic equation, the quenching reaction of MP to OVA was static quenching, which was brought on by the combination of two molecules to shape a complex. At 298 K, the conjunction constant K_a of MP and OVA was 1.045 2 × 10⁹ L/mol, and the count of conjunction sites n was 1.955 7. The thermodynamic constant of MP-OVA binding was counted according to Van’s Hoff equation, and the reaction belonged to the active process of reducing Gibbs free energy. The ultraviolet–visible (UV-Vis) absorption spectroscopy indicated an interaction between MP and OVA. The interaction force between MP and OVA and the steadiness of the conjunction were examined by using molecular docking and molecular dynamics simulation. The findings suggested that MP formed a complex with OVA via non-covalent binding, the formation and steadiness of the complex were promoted through hydrogen bonding, hydrophobic interaction, and Van der Waals force.

The objective of this study was to investigate the effects of agar oligosaccharide-iron (AOS-iron) on intestinal tissue pathology and microbiota in IDA rats induced by a low-iron diet, further to find the relationship between intestinal microbiota and iron metabolic disorders. After 4 weeks of AOS-iron supplementation, the fecal iron content of IDA rats markedly increased in a dose-dependent manner, only the damaged cecum and colon tissues in medium-dose (MD) and high-dose (HD) groups were repaired to the baseline, while the diversity of gut microbiota was improved even at low dose (LD). Furthermore, the supplementation of AOS-iron altered the composition of gut microbiota. At the genus level, the beneficial microbiota was enriched in AOS-iron groups, but the relative abundance of potential opportunistic pathogens obviously reduced compared to that in the anemia model (AM) group. Spearman's correlation analysis revealed that biochemical parameters, including blood metabolic parameters, iron contents, body weight, GSH-PX and T-AOC activity, were positively correlated with SMB53, Anaerotruncus, Anaerostipes and Coprobacillus but negatively correlated with Morganella, Fusobacterium and Serratia. These findings indicated that AOS-iron effectively repaired the damaged intestinal tissue and ameliorated iron metabolic disorders by regulating gut microbiota desirably, which could provide references for the treatment of IDA.