The research on tyrosinase inhibition and biological activity of cinnamaldehyde and its derivatives

酪氨酸酶（EC1.14.18.1）是一种含铜的氧化还原酶，广泛分布于微生物，动物，植物和人体中，是生物体生命活动的关键酶。若人体中酪氨酸酶异常表达能引起雀斑和黑色素沉积等皮肤病，且其在昆虫的蜕皮及果蔬褐变中起了关键的作用，因此酪氨酸酶抑制剂的研究引起了广泛的关注。肉桂醛主要存在于天然樟科植物桂皮中，在农业、医药上具有重要的作用。 本文首先以蘑菇酪氨酸酶为对象，研究了肉桂醛及其α位C上取代的三种衍生物：α-溴代肉桂醛、α-氯代肉桂醛和α-甲基肉桂醛对酶的抑制作用，结果表明四者抑制50%单酚酶活性的浓度（IC50）分别为1.210，0.075，0.140，0.440mmol/L；对二酚酶的IC5...Tyrosinase (EC 1.14.18.1), a copper containing enzyme, is widely distributed in microorganisms, animals, plants and human beings. It is the key enzyme in the vital function of biology. In human, tyrosinase is responsible for skin pigmentation abnormalities, such as flecks and defects. Furthermore, tyrosinase causes browning in vegetables, fruits and mushrooms. Therefore, The inhibitors of tyrosina...学位：理学硕士院系专业：生命科学学院_生物化学与分子生物学学号：2162013115257

Anti-tyrosinase Activity Kinetics and Insecticidal Efficacy of a -Bromocinnamaldehyde

运用酶活性染色和酶抑制动力学方法分析了a-溴代肉桂醛对蘑菇酪氨酸酶的抑制作用,测得酶的正向和逆向速率常数分别为2.793; L/(mmol·min)和$1.98 \times {10^{ - 3}}{{\mathop{\rm s}\nolimits} ^{ -; 1}}$.在此基础上探讨了a-溴代肉桂醛对棉铃虫(Helicoverpa armigera)的毒杀作用,发现经0.625; mmol/L溴代肉桂醛处理后,棉铃虫3龄幼虫的生长发育受到一定程度限制,当a-溴代肉桂醛浓度达5.0 mmol/L时,在作用48; h后致死.此外,经5.0; mmol/L溴代肉桂醛处理后,棉铃虫3龄幼虫的活体和离体多酚氧化酶(PPO)活力受到了显著抑制.上述结果为今后a-溴代肉桂醛在食品、农业、医药等; 方面的应用提供了理论和实践基础.The inhibitory effect of a-bromocinnamaldehyde on mushroom tyrosinase; was investigated in this study using enzyme activity staining and enzyme; inhibitory kinetics.The rate constants of the forward (k_(+0)) and; reverse (k_(-0)) reactions were determined to be 2.793 L/(mmol·min) and; $1.98 \times {10^{ - 3}}{{\mathop{\rm s}\nolimits} ^{ -; 1}},respectively.Moreover,the insecticidal efficacy of; a-bromocinnamaldehyde was determined. As expected,the larval growth and; survival rate of Helicoverpa armigera were found to be reduced after; supplemented with 0.625 mmol/L a-bromocinnamaldehyde as compared to the; control larvae, and the larvae were totally dead after 48 h treatment; with 5.0 mmol/L a-bromocinnamaldehyde.The polyphenol oxidase (PPO); activities were inhibited by 5.0 mmol/L a-bromocinnamaldehyde both in; vivo and in vitro.These results may provide theoretical and practical; basis in the application of a-bromocinnamaldehyde in food,agriculture; and medicine.国家自然科学基

Anti-tyrosinase Activity Kinetics and Insecticidal Efficacy of α-Bromocinnamaldehyde

运用酶活性染色和酶抑制动力学方法分析了α-溴代肉桂醛对蘑菇酪氨酸酶的抑制作用,测得酶的正向和逆向速率常数分别为2.793L/（mmol·min）和1.98×10^-3 s^-1.在此基础上探讨了α-溴代肉桂醛对棉铃虫（Helicoverpa armigera）的毒杀作用,发现经0.625mmol/Lα-溴代肉桂醛处理后,棉铃虫3龄幼虫的生长发育受到一定程度限制,当α-溴代肉桂醛浓度达5.0mmol/L时,在作用48h后致死.此外,经5.0mmol/Lα-溴代肉桂醛处理后,棉铃虫3龄幼虫的活体和离体多酚氧化酶（PPO）活力受到了显著抑制.上述结果为今后α-溴代肉桂醛在食品、农业、医药等方面的应用提供了理论和实践基础.The inhibitory effect ofα-bromocinnamaldehyde on mushroom tyrosinase was investigated in this study using enzyme activity staining and enzyme inhibitory kinetics.The rate constants of the forward（k＋0）and reverse（k-0）reactions were determined to be 2.793L/（mmol·min）and 1.98×10^-3 s^-1,respectively.Moreover,the insecticidal efficacy ofα-bromocinnamaldehyde was determined.As expected,the larval growth and survival rate of Helicoverpa armigera were found to be reduced after supplemented with 0.625mmol/Lα-bromocinnamaldehyde as compared to the control larvae,and the larvae were totally dead after 48 htreatment with 5.0mmol/Lα-bromocinnamaldehyde.The polyphenol oxidase（PPO）activities were inhibited by 5.0mmol/Lα-bromocinnamaldehyde both in vivo and in vitro.These results may provide theoretical and practical basis in the application ofα-bromocinnamaldehyde in food,agriculture and medicine.国家自然科学基金（31271952