Studies on Synthesis of Hydroxy Subsituted of N-Benzoyltyramine Derivatives as Inhibitory Activity of Antioxidant and Tyrosinase
| Autor: | Kun-ying Lin, 林昆瑩 |
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| Rok vydání: | 2009 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 97 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. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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