Departamento de Química Fundamental, Universidade Federal de Pernambuco, Recife 50670-901, PE, Brazil.
Faculdade de Ciências Educação e Tecnologia de Garanhuns, Universidade de Pernambuco, Garanhuns 55290-000, PE, Brazil.
Int J Biol Macromol. 2019 Feb 1;122:289-297. doi: 10.1016/j.ijbiomac.2018.10.175. Epub 2018 Oct 26.
Here, we evaluate spiroacridines as inhibitors of tyrosinase, a key enzyme to melanogenesis. For this purpose, the spiroacridines 3-(acridin-9-yl)-N-benzylidene-2-cyanoacrylohydrazide (AMTAC-01) and 3-(acridin-9-yl)-2-cyano-N-(4-metoxybenzylidene)-acrylohydrazide (AMTAC-02) were synthesized and their enzymatic inhibition types and mechanisms were investigated. In addition, the interaction of these compounds with the enzyme were studied by UV-Vis spectroscopy, spectrofluorimetry, H NMR titration as well as molecular docking. Spectroscopic results reveals that the acridine derivatives interact strongly (K ≅ 10 - 10 M) with the mushroom tyrosinase and the enzyme undergoes small structural modifications due to the interaction with AMTAC-01 compound. The interaction studies support the enzymatic inhibition results, which suggests that AMTAC-01 compounds inhibit the enzyme reversibly and follows a noncompetitive type (AMTAC-01) and mixed type (AMTAC-02) of inhibition. Nevertheless, AMTAC-02 (IC = 96.29 μM) inhibits the enzyme more effectively than AMTAC-01 (IC = 189.40 μM), which suggests a highly relevant role of AMTAC-02's methoxy group to the inhibition activity, which is confirmed by docking studies to mushroom tyrosinase. Docking also indicates this interaction to be absent in human tyrosinase. SIGNIFICANCE: Based on previous results which evidenced the relevant activity of two spiroacridinic compounds for cell growth inhibition against melanoma cells, here we improve our understanding about the spiroacridines in the biological media by exploring the molecular mechanism that govern the activities of these two compounds using mushroom tyrosinase (mTYR) enzyme as molecular target. The paper not only will have a major impact upon molecular mechanism that regulates melanin inhibition by spiroacridinic compounds, but also by guiding the search for enzyme inhibitors and the development of new anti-melanoma prophylaxis.
在这里，我们评估了螺[吖啶-9,2'-嘧啶]-2-甲腈缩氨基脲（AMTAC-01）和 3-（吖啶-9-基）-2-氰基-N-（4-甲氧基苯亚甲基）丙烯酰肼（AMTAC-02）作为酪氨酸酶抑制剂，酪氨酸酶是黑色素生成的关键酶。为此，合成了螺[吖啶-9,2'-嘧啶]-2-甲腈缩氨基脲（AMTAC-01）和 3-（吖啶-9-基）-2-氰基-N-（4-甲氧基苯亚甲基）丙烯酰肼（AMTAC-02），并研究了它们的酶抑制类型和机制。此外，通过紫外可见光谱、荧光光谱、1H NMR 滴定以及分子对接研究了这些化合物与酶的相互作用。光谱结果表明，吖啶衍生物与蘑菇酪氨酸酶强烈相互作用（K ≅ 10-10 M），并且由于与 AMTAC-01 化合物的相互作用，酶发生了微小的结构修饰。相互作用研究支持酶抑制结果，表明 AMTAC-01 化合物可逆地抑制酶，遵循非竞争性类型（AMTAC-01）和混合类型（AMTAC-02）的抑制。然而，AMTAC-02（IC=96.29 μM）比 AMTAC-01（IC=189.40 μM）更有效地抑制酶，这表明 AMTAC-02 的甲氧基基团对抑制活性有高度相关性，这通过对接研究得到了证实蘑菇酪氨酸酶。对接还表明，这种相互作用在人酪氨酸酶中不存在。意义：基于先前的结果，即两种螺[吖啶-9,2'-嘧啶]化合物对黑色素瘤细胞的细胞生长抑制具有相关活性，我们通过探索控制这两种化合物活性的分子机制，使用蘑菇酪氨酸酶（mTYR）作为分子靶点，来提高我们对生物介质中螺[吖啶-9,2'-嘧啶]化合物的理解。本文不仅对调节螺[吖啶-9,2'-嘧啶]化合物抑制黑色素的分子机制有重大影响，而且还可以指导寻找酶抑制剂和开发新的预防黑色素瘤的方法。
