|摘要: ||本研究主要利用有機合成方法，將原兒茶酸(protocatechuic acid)及咖啡酸(caffeic acid)進行酯化或醯胺化，得到一系列之酯類(編號1 ~ 10)及醯胺類(編號11 ~ 16)衍生物，經由清除DPPH自由基能力的測試、抑制酪胺酸酶(Tyrosinase)活性的測試、MTT細胞毒性試驗及人體之有效性評估，探討其在化粧品上的應用價值。
在清除DPPH自由基結果方面發現：原兒茶酸之酯化衍生物(編號1 ~ 7)比醯胺化衍生物(編號11 ~ 13)，對DPPH自由基有較佳之清除效果，其中以Compound 3 (Propyl 3,4-dihydroxybenzoate)之IC50 = 2.48 μg/ml為最低。且原兒茶酸衍生物之抗氧化效果整體而言皆優於咖啡酸之衍生物。
在酪胺酸酶活性抑制的結果方面發現：原兒茶酸之含苯酯化衍生物(編號5~7)的抑制效果最好，其中以Compound 6 (2-phenyl- ethyl 3,4-dihydroxybenzoate)之IC50 = 13.61 μg/ml最低；而Compound 7 (3-phenylpropyl 3,4-dihydroxybenzoate)之IC50 = 16.41 μg/ml次之。此兩種化合物之抑制效果較原兒茶酸、咖啡酸、維生素C甚至麴酸更好。
在細胞毒性實驗結果方面發現：以Compound 1 ~ 4及11之存活率較高(IC50 = 102.74，103.67，98.24，95.92及93.07 μg/ml，皆大於或接近於100 μg/ml)。
在人體有效性試驗方面：經由DPPH抗氧化試驗、酪胺酸酶活性抑制試驗及MTT細胞毒性試驗中，挑選出具有抗氧化、美白且安全性高之化合物進行實際塗抹測試，發現以Compound 11 (N-hexyl 3,4-dihydroxybenzamide)之效果最好。
因此由本研究所合成之Compound 11 (N-hexyl 3,4-dihydroxy- benzamide)，同時具有低毒性、美白和抗氧化等特性，其合成步驟簡單，可進一步大量開發成具有美白兼抗氧化之複合幼藺吨帖~，因此在消費巿場上極具商品化之潛力。
This research utilizes the method of organic synthesis to put protocatechuic acid and caffeic acid into esterification or amidation process so as to produce a series of esters (No. 1 ~ 10) and amides (No. 11 ~ 16). By way of tests on DPPH antioxidant capability, inhibit- tive capability on the vitality of tyrosinase, MTT cell toxicity test and appraisal of validity of human body, their practical values in cosmetics will be further discussed.
The experiment on antioxidant capability shows that: the alkyl ester esterification derivatives of protocatechuic (No. 1 ~ 7) have better effects to clean DPPH than amidation derivatives of proto- catechuic (No. 11 ~ 13), and IC50 = 2.48 μg/ml of Compound 3 (Pro- pyl 3,4-dihydroxybenzoate) is the lowest especially. And the antioxidant capability of the alkyl ester derivatives of protocatechuic are better than that of caffeic acid.
The experiment on inhibitive capability on the vitality of tyrosinase shows that: the alkyl ester esterification derivatives with benzene of protocatechuic acid (No. 5 ~ 7) have better inhibitive capability on the vitality, and IC50 = 13.61 μg/ml of Compound 6 (2-phenylethyl 3,4-dihy- droxybenzoate) is the lowest especially; IC50 = 16.41 μg/ml of Compound 7 (3-phenylpropyl 3,4-dihydroxybenzoate) is the inferior one. The inhibitive capability of these two compounds are better than protocatechuic acid, caffeic acid, vitamin C even kojic acid.
The experiment on cell toxicity shows that: survival percentage of Compounds 1 ~ 4 and 11 is the highest (IC50 = 102.74, 103.67, 98.24, 95.9 and 93.07 μg/ml，are larger than or approach to 100 μg/ml).
The experiment of validity on human body shows that: by way of DPPH antioxidant capability, inhibitive capability on the vitality of tyrosinase and MTT cell toxicity test, to pick the compounds that have anti-aging, whitening functions and high safety to carry on the practical test by spreading. It is found that the effect of Compound 11 (N-hexyl 3,4-dihydroxybenzamide) is best.
It is found that the Compound 11 (N-hexyl 3,4-dihydroxybenzamide) made in this research can be easily synthesized and has high rate of production, low toxicity, whitening and anti-aging functions, which can be further developed into cosmetics with whitening and anti- aging functions and therefore has great potential in consumer market.