| 摘要: | 本研究主要利用有機合成的方法，將一系列不同數量及在不同位置的羥基取代之苯甲酸分別與酪胺或多巴胺進行醯胺化反應後，得到一系列的羥基取代之Ｎ-酪胺苯甲醯胺類衍生物（Compounds 1~20），再經由下列不同體外活性測試方法：一、抗氧化能力—清除DPPH自由基與ABTS自由基 二、抑制酪胺酶美白活性測試 三、紫外線/可見光光譜儀吸收測試；並分別以Trolox、維生素C、熊果素、Octyl salicylate當對照組標準品，進一步探討其在化粧品上的應用價值。
在清除DPPH自由基結果顯示，羥基取代之Ｎ-酪胺苯甲醯胺類衍生物具有相當不錯的抗氧化能力，其SC50值介於10.36±0.41μg/ml~32.59±4.54 μg/ml之間，其中又以化合物17效能最強（SC50=10.36±0.41μg/ml），抗自由基能力優於對照組trolox（SC50 = 13.36±0.42μg/ml）。而化合物清除DPPH自由基的能力與羥基數量及其取代位置有關，當苯環上羥基取代數量越多，其清除DPPH自由基能力就越強，另外，羧酸苯環上二羥基取代位置互為鄰位或對位時，其抗氧化能力明顯較間位強。
羥基取代之Ｎ-酪胺苯甲醯胺類衍生物在總抗氧化能力清除ABTS自由基活性測試結果顯示，大部分衍生物皆有良好的抗氧化活性（SC50 =2.56±0.12 ~ 6.08±0.37 μg/ml），除了多巴胺的單羥基取代衍生物（Compound 13，SC50 =6.08±0.37 μg/ml）比標準對照組Trolox（SC50 =5.27±0.79 μg/ml）差之外，其餘皆比Trolox來的強。
在抑制酪胺酸酶活性結果顯示，compound 17（IC50=0.11±0.01 mg/ml）具有抑制酪胺酸酶的效能，效果比熊果素（IC50=0.96±0.07 mg/ml）好，且與Vit C（IC50=0.08±0.01 mg/ml）效果相似。
在紫外線吸收測試結果顯示，所有化合物皆有紫外線吸收能力，最大吸收波長介於258~275 nm，吸光值介於0.208~1.160之間。其中又以Compounds 1、2、3、4、7、8、10、11、14、16、17之吸光值大於對照組Octyl salicylate（Abs=0.152）。此外，化合物5、6、15、16證實具有UVA之吸收；根據以上的結果，所有化合物皆具有良好的紫外線吸收能力。
This research utilized the method of organic synthesis to put different amounts and positions of hydroxy-substituted tyramine or hydroxy- substituted dopamine into benzoic acid so as to produce a series of hydroxy-substituted N-benzoyltyramine derivatives (Compounds 1~20). Through the following tests, I. The ability of antioxidant—to scavenge DPPH free radical and ABTS free radical, II. The activity test of inhibit tyrosinase, III. The activity test of absorb UV in UV-Vis spectrometer. Compared with controlled groups, such as trolox, vitamine C, arbutin, and octyl salicylate, and this research studies those compounds’ applied value of cosmetics.
The results of the experiment to scavenging DPPH free radical shows that hydroxy-substituted N-benzoyltyramine derivatives has the ability in antioxidant, the SC50 of which ranges from 10.36±0.41μg/ml to 32.59±4.54 μg/ml. More specifically, compound 17 has the most outstanding effect in antioxidant (SC50 = 10.36±0.41μg/ml), compared with controlled group, trolox (SC50 = 13.36±0.42 μg/ml). In sums, that all derivatives ability to scavenge DPPH free radical which is related to the amount of substitution of hydroxy groups and their positions. The more hydroxy groups substituted at the benzene ring, the scavenging of DPPH free radical is more stronger, otherwise, the substitution of two hydroxy groups are at the ortho-position or para-position of carboxylic acid benzene ring, the ability of antioxidant is apparently more stronger.
The results in the experiments of the ability of antioxidant—to scavenge ABTS free radical—shows that all hydroxy substituted N-benzoyltyramine derivatives have good antioxidant activity, the SC50 of which ranges from 2.56±0.12μg/ml to 6.08±0.37 μg/ml. Almost each derivatives are stronger than controlled group, trolox (SC50 =5.27±0.79 μg/ml), except mono-hydroxy substituted derivative (Compound 13, IC50 =6.08±0.37 μg/ml).
The result of inhibiting tyrosinase shows that compound 17(IC50=0.11±0.01 mg/ml) have the ability to inhibit tyrosinase. It’s activity is better than arbutin (IC50=0.96±0.07 mg/ml), and similar with vitamin C.
According to the result of absorbing UV shows that all derivatives have the absorbing ultraviolet. The λmax absorbed is between 258~275 nm, and Abs is between 0.208~1.160. Remarkably, the ability to Abs of compounds 1, 2, 3, 4, 7, 8, 10, 11, 14, 16 and 17 is better than controlled group, octyl salicylate (Abs=0.152). Moreover, Compounds 5, 6, 15, 16 are proven to be able to absorb UVA. In sums, that hydroxy-substituted N-benzoyltyramine derivatives have the ability of absorbing ultraviolet. |
