WEKO3
アイテム
Structure-Activity and Structure-Mechanism Relationships for the Radical-Scavenging Reaction of Flavonols
https://repo.qst.go.jp/records/75179
https://repo.qst.go.jp/records/751796b712458-6863-451e-9aff-df246a5dd19c
| Item type | 会議発表用資料 / Presentation(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2019-03-15 | |||||
| タイトル | ||||||
| タイトル | Structure-Activity and Structure-Mechanism Relationships for the Radical-Scavenging Reaction of Flavonols | |||||
| 言語 | ||||||
| 言語 | eng | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_c94f | |||||
| 資源タイプ | conference object | |||||
| アクセス権 | ||||||
| アクセス権 | metadata only access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
| 著者 |
Nakanishi, Ikuo
× Nakanishi, Ikuo× Ohkubo, Kei× Imai, Kohei× Ken-ichiro, Matsumoto× Ozawa, Toshihiko× Hamada, Hiroki× Fukuhara, Kiyoshi× Nakanishi, Ikuo× Ohkubo, Kei× Imai, Kohei× Matsumoto, Kenichiro× Ozawa, Toshihiko |
|||||
| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | Flavonols show an efficient scavenging activity against reactive oxygen radicals. However, the detailed mechanism has yet to be fully clarified. There are two mechanism for the radical-scavenging reactions of phenolic antioxidants, i.e., one-step hydrogen-atom transfer (HAT) and electron transfer followed by proton transfer (ET-PT). In this study, we discuss the radical-scavenging mechanism for 6 flavonols, which are myricetin (Myr), quercetin (Que), kaempferol (Kae), and 3 methylated quercetin analogs (2’-MeQue, 5’-MeQue, and Me2Que), based on the relationships between the scavenging rate constants (k) against galvinoxyl radical and thermodynamic parameters, such as O-H bond dissociation energies (DHT) and ionization potentials (IP), calculated by the density functional theory (DFT). The k values were determined in deaerated acetonitrile at 298 K by a stopped-flow technique. DFT calculations were carried out at the B3LYP/6-31G(d) level. The k value increases in the order: Que < 2’-MeQue ≈ Kae < Me2Que < Myr < 5’-MeQue. The plot of the logarithm of the k values (log k) vs. DHT or IP values revealed that the log k values for 5’-MeQue, Myr, Me2Que, and Que are linearly correlated with their IP values. These results suggest that the radical-scavenging reaction by these 4 flavonols may proceeds via the ET-PT mechanism. |
|||||
| 会議概要（会議名, 開催地, 会期, 主催者等） | ||||||
| 内容記述タイプ | Other | |||||
| 内容記述 | The 9th Biennial Meeting of Society for Free Radical Research-Asia (SFRR-Asia) | |||||
| 発表年月日 | ||||||
| 日付 | 2019-04-06 | |||||
| 日付タイプ | Issued | |||||
