類去氧苯因的抗氧化性質研究

Antioxidant Properties of Deoxybenzoinoids

本研究針對四個合成類去氧苯因，包含： (DOB)2,4-dihydroxy-4’-methoxydeoxybenzoin(DOB-1a)、2,4-dihydroxy-3’,4’-dimethoxydeoxybenzoin (DOB-2b)、2,3,4-trihydroxy-3’,4’-dimethoxydeoxybenzoin (DOB-3c) 及3,4-dihydroxy-3’,4’-dimethoxydeoxybenzoin (DOB-4d)等，研究它們的總抗氧化能力、金屬嵌合、還原能力、及對ABTS、DPPH 與超氧陰離子等自由基的清除活性之抗氧化性質評估，結果顯示DOB-1a、DOB-2b、DOB-3d 及DOB-4d 等皆比Trolox（對照抗氧化劑）具有更強的ABTS 自由基清除能力，DOB-3c 具有最佳的抗脂質過氧化及超氧陰離子自由基清除活性，DOB-4d 則是最佳的DPPH 自由基清除作用，同時，除了DOB-4d 外，其他DOBs 的還原能力都比Trolox 弱，這些DOBs 的金屬嵌合能力也都偏弱，此研究發現DOB 第一個環上的羥基取代數量對其抗氧化能力影響最大。

In this study, four deoxybenzoid derivatives namely 2,4-dihydroxy-4’-methoxydeoxybenzoin (DOB-1a), 2,4-dihydroxy-3’,4’-dimethoxydeoxybenzoin (DOB-2b), 2,3,4-trihydroxy-3’,4’-dimethoxydeoxybenzoin (DOB-3c) and 3,4-dihydroxy-3’,4’- dimethoxydeoxybenzoin (DOB-4d) were synthesized and were evaluated for total antioxidant, metal chelating, reducing power, ABTS, DPPH and superoxide radical scavenging activities. Results showed that DOB-1a, DOB-2b, DOB-3d and DOB-4d possessed a stronger ABTS radical scavenging activity than Trolox (a reference standard). Compared with the other DOBs, DOB-3c demonstrated the strongest anti-lipid peroxidation and superoxide radical scavenging activities. However, DOB-4d showed the best activity in DPPH radical scavenging. Besides DOB-4d, other DOBs exhibited a weaker reducing power than Trolox. All tested DOBs showed a weak activity in metal chelation. This study indicates that the number of hydroxyl groups on the first ring of DOBs may play an important role in the potency of DOB antioxidant activities.