In Silico Study of Amylose Complexation with Quinoa (Chenopodium quinoa Willd.) Phenolic Compounds Under Different...

In this study, an in silico assessment of complex formation between amylose chains and quinoa phenolic compounds was performed to examine the effect of temperature on amylose conformation and binding affinity. Four representative phenolic compounds with diverse structures (cinnamic acid, kaempferol, isofraxidin, and chrysoeriol) previously reported as digestive enzyme inhibitors were selected. An 18-unit glucose amylose chain was modeled and subjected to molecular dynamics (MD) simulations at 293.15 K, 323.15 K, 343.15 K, and 368.15 K. The resulting structures were used as receptors in the molecular docking simulations using AutoDock 4.2.6 and AutoDock Vina 1.1.2. Intermediate temperature conformations (323.15 K and 343.15 K) favored the formation of optimal helical cavities for ligand interactions. Kaempferol exhibited the lowest binding free energy and high thermal stability, while isofraxidin and chrysoeriol showed greater temperature sensitivity. Hydrogen bond analysis revealed optimal distances (1.8-2.3 Å), particularly for kaempferol and cinnamic acid at intermediate temperatures. The interactions were influenced by the hydroxyl group count, steric hindrance, and spatial arrangement of the functional groups. Importantly, phenolic compounds can modulate starch digestibility through non-covalent interactions, potentially influencing the postprandial glycemic response. Overall, this study demonstrates that thermal conditions significantly shape the affinity of phenolics for amylose and highlights the potential of flavonoids, especially kaempferol, in the design of functional foods with modified starch and a reduced glycemic index.