Role of the Solvent and Intramolecular Hydrogen Bonds in the Antioxidative Mechanism of Prenylisoflavone from Leaves of .

This work discusses the electron structure, antioxidative properties, and solvent contribution of two new antioxidant molecules discovered, named and , extracted from a medicinal plant called , found in the Amazon rain-forest. To gain a better understanding, a study using density functional theory coupled with the polarizable-continuum model and the standard 6-311++G(d,p) basis set was conducted. The results indicate that has a higher antioxidant potential than , confirming the experimental expectations. In the gas phase, the hydrogen atom transfer route dominates the hydrogen scavenging procedure. However, in the water solvents, the antioxidant mechanism prefers the sequential proton loss electron transfer mechanism. Furthermore, the solvent plays a fundamental role in the antioxidant mechanism. The formation of an intramolecular OH···OCH hydrogen bond is crucial for accurately describing the hydrogen scavenging phenomenon, better aligning with the experimental data. The results suggest that the two isoflavones investigated are promising for the pharmacologic and food industries.