Computational Study of Antioxidant Activity and Bioavailability of Papua Red Fruit (Pandanus conoideus Lam.) Flavonoids Through Docking Toward Human Serum Albumin

摘要

Red Fruit (RF) (Pandanus conoideus Lam.) is popular as a source of antioxidant flavonoids, but those may differ in bioavailability in the human body. Binding on Albumin may influence the flavonoid ability as an antioxidant. It was influenced by the flavonoid structures. There is no study focus on the antioxidant activity and bioavailability of RF flavonoids intracellularly, and the structures influenced on the molecular interactions and antioxidant activity intracellularly. This research objective is the analysis of RF flavonoids bioavailability and antioxidant activity by in silico study; focus on the structures relationships, to enlighten their role as an antioxidant in molecular level. Five RF flavonoids were analyzed by in silico for their antioxidant activity and bioavailability, comparing to Quercetin, Quercetin-3'-Glucoside, and Taxifolin as a standard. Chemical structures were redrawn online using PubChem Sketcher. Antioxidant activities were predicted using PASSonline. The flavonoids were docked to Human Serum Albumin/HSA using Autodock Vina in Pyrx 0.8. The 3D molecular interactions were visualized using PYMOL then analyzed by Ligplot~+. Taxifolin3-O-α-Arabinopiranose/TAP, 4',6,6',8-tetrahidroxy-3-metoxy-flavon/TMF; 3,4',5-trihydroxy-7,3'-dimethoxyflavone; Quercetin3-O-Glucose/QOG, Quercetin3-Methyl-Ether showed Pa>0,7 for antioxidant in general (except TMF), free radical scavenging, and lipid peroxidase inhibitor activity. The highest Pa was given by TAP and QOG that higher than Quercetin. TAP and QOG also gave the highest binding affinity when docking onHSA. Only TAP had a same binding affinity as Quercetin (-8,2 kcal/mol); docked on the FA7 site at Ser216 residue. Hydroxylation of RF flavonoids more influenced bioavailability and then antioxidant activity than methylation. The structure like TAP in Red Fruit showed the highest bioavailability and antioxidant activity, which similar to Quercetin.