Theoretical investigation on electron transfer-based antioxidant activity of melinjo resveratrol

We employ density functional calculations to study the electron transfer-based antioxidant activity of resveratrol derivatives from melinjo. The derivatives are monomer resveratrol which is trans-resveratrol, and dimer resveratrol which are gnetin C, gnetin L, and gnemonoside C. The results show that gnetin C has the lowest adiabatic ionization potential both in gas phase and water environment. Furthermore, our results demonstrate that dimer resveratrol is consistent to have better electron transfer ability than its monomer. This may due to the destabilization of the high occupied molecular orbital energy of resveratrol. However, the presence of glucoside in gnemonoside C does not affect the electron transfer-based antioxidant activity of dimer resveratrol

Theoretical exploration on free radical scavenging mechanism of curcumin analogues in water solvent

One way to improve curcumin's possibility in preventing lipid peroxidation is through modification of carbon linker, β-diketone group and aromatic rings. However, there remains a need to explore the role of carbon linker on the free radical scavenging mechanisms of curcumin. This study uses density functional theory to explore two descriptors of free radical scavenging mechanisms, which are bond dissociation enthalpy (BDE) and adiabatic ionization potential (AIP) of curcumin and its analogues. Five analogues with different amount of carbon atoms in the linker in the presence / absence of β-diketone group are chosen. Our result shows that decreasing the amount of carbon atom from 7 to 5 atoms in the linker decreases the BDE at β-diketone group of the curcumin analogue. Moreover, increasing the amount of carbon atoms in the linker decreases the AIP of the analogues