@misc{oai:repo.qst.go.jp:00076636,
 author = {Fukuhara, Kiyoshi and Imai, Kohei and Nakanishi, Ikuo and Ken-ichiro, Matsumoto and Ohno, Akiko and Imai, Kohei and Nakanishi, Ikuo and Matsumoto, Kenichiro and Ohno, Akiko},
 month = {Aug},
 note = {The main effects mediated by reactive oxygen species (ROS) relate to its potential to cause oxidative damage in cells and tissues.  Therefore, a ROS burst contributes to cellular dysfunction and can cause a wide range of chronic diseases.  Polyphenol, such as catechin and resveratrol, is capable of scavenging ROS, resulting in the prevention of oxidative stress related diseases.  In this study, planar catechin (PCat), in which the geometry of catechin is constrained to be planar, was conjugated to metal cheater, DTPA.  the antioxidative activity of the compound (PCat-DTPA) was evaluated in terms of the capacity to scavenge 2,2-diphenhydramine-1-picrylhydrazyl (DPPH) radical as an oxyl radical species.  The compound (PCat-DTPA) showed weak antioxidative activity compared to the planar catechin due to intramolecular hydrogen bonding between DTPA with catechol moiety of the catechin structure.  Alternatively, in the presence of Fe(3+), the antioxidative activity of PCat-DTPA greatly increased 345-fold, which was 3-fold compared to that of PCat.  The strong antioxidative activity of PCat-DTPA in the presence of Fe(3+) was also shown by the Fenton system and hypoxanthin-xanthin oxidase system.  The enhanced radical-scavenging activity of PCat-DTPA compared to PCat suggested that the reduction of the DPPH radical with PCat-DTPA accelerated by Fe(3+) mediated electron transfer.  Transition metal ions, which have an ability to produce ROS by redox cycle, demonstrate the role of positive oxidative stress in age-related diseases.  However, PCat-DTPA exhibits more potent antioxidative activity by coordinating with Fe(3+).  Therefore, the compound is a promising seed for the new antioxidant for the treatment of the oxidative stress-related diseases., ACS Fall 2019 National Meeting & Expo},
 title = {Planar Catechin Conjugated with DTPA as a Promising Antioxidant Triggered by Fe3+ Coordination},
 year = {2019}
}