Antioxidative Activity of Urushiol Derivatives from the Sap of Lacquer Tree (Rhus vernicifera Stokes)

Antioxidative Activity of Urushiol Derivatives from the Sap of Lacquer Tree (Rhus vernicifera Stokes)

The authors isolated four olefinic catechols, commonly referred to as urushiol, from the sap of Korean lacquer tree (Rhus vernicifera STOKES) with stronger antioxidative activities than α-tocopherol. The hexane extract with a free radical scavenging activity was purified by silica and ODS gel column chromatography. The active compounds were identified by MS and H-NMR as 3-[8 (Z), 11 (Z), 14 -pentadecatrienyl]catechol, 3-[8 (Z), 11 (Z)-pentadecadienyl]catechol, 3-[8 (Z)-pentadecenyl] catechol, and 3-pentadecylcatechol. All of these compounds showed strong free radical scavenging activities on 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical, in which 3-pentadecylcatechol exhibited the highest activity (IC50: 1.2 ㎍/㎖). They also showed a significant inhibitory activity on lipid peroxidation (IC50: 2.1 - 3.5 ㎍/㎖). The antioxidative activity of 3-pentadecylcatechol on DPPH radical and lipid peroxidation is approximately two times greater than that of α-tocopherol. The results suggest that the urushiol derivatives may contribute to the preservative characteristics effective against oxidative stress and could be a good source for industrial applications including a coating material.