Jamali Zohreh, Rezaei Behbehani Gholamreza, Zare Karim, Gheibi Nematollah
Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, Iran.
Department of Chemistry, Imam Khomeini International University, Qazvin, Iran.
J Food Biochem. 2019 Mar;43(3):e12728. doi: 10.1111/jfbc.12728. Epub 2018 Nov 28.
The estreification of chrysin with α-Linolenic acid (complex I) and linoleic acid (complex II) poly unsaturated fatty acids resulted to design of new mushroom tyrosinase (MT) inhibitors. Thermodynamic parameters of enzymes, including the melting point (T ) and ∆G values, were obtained from thermal and chemical denaturation curves. Complexes I and II showed a competitive inhibitory effect on MT with K values of 0.45 and 0.29 mM, respectively. The T values were calculated as 328.6, 322.4, and 318 K and the ∆G values as 62.8, 52.9, and 47.1 KJ mol for the enzyme alone and its interaction with complexes I and II, respectively. Intrinsic and extrinsic fluorescence techniques showed structural instability of the enzyme in concomitance with a decrease in the regular secondary structure acquired using CD spectrometry. This data clearly prove that the new derivatives show a stronger inhibitory effect than the separate compounds. Molecular docking analysis showed that the best possible interaction condition was achieved for chrysin with n-6. PRACTICAL APPLICATIONS: MT is a suitable model in medicine for the investigation of melanogenesis, skin disorders, and hyperpigmentation because of its accessibility and close structural similarity to mammalian tyrosinase. In recent years, the designing of tyrosinase inhibitors from natural substances for prevention of hyperpigmentation in medicine, skin cosmetics, and undesired browning in agriculture and food industry has risen sharply. Many of the pharmaceutical products based on the use of flavonoids and poly unsaturated acids as natural compounds or on their semi-synthetic derivatives have been interested for investigations because of their usefulness in many pathological conditions such as inflammation, cancer, and skin disorders. The limitation of the flavonoids applications are low bioavailability, permeability, and solubility for the cells. In this study, conjugation of chrysin with n-3 and n-6 fatty acids resulted in a stronger inhibitors of MT with a synergic inhibitory effect on its activity.
白杨素与α-亚麻酸(配合物I)和亚油酸(配合物II)等多不饱和脂肪酸的酯化反应产生了新型蘑菇酪氨酸酶(MT)抑制剂。酶的热力学参数,包括熔点(T)和∆G值,是从热变性和化学变性曲线中获得的。配合物I和II对MT表现出竞争性抑制作用,K值分别为0.45和0.29 mM。单独的酶及其与配合物I和II相互作用时,计算得到的T值分别为328.6、322.4和318 K,∆G值分别为62.8、52.9和47.1 KJ mol。内在和外在荧光技术表明,酶的结构不稳定,同时使用圆二色光谱法获得的规则二级结构减少。这些数据清楚地证明,新衍生物比单独的化合物具有更强的抑制作用。分子对接分析表明,白杨素与n-6达到了最佳的可能相互作用条件。实际应用:由于MT易于获取且与哺乳动物酪氨酸酶结构相似,因此它是医学上研究黑色素生成、皮肤疾病和色素沉着过度的合适模型。近年来,从天然物质设计酪氨酸酶抑制剂以预防医学上的色素沉着过度、皮肤化妆品以及农业和食品工业中不期望的褐变现象急剧增加。许多基于使用黄酮类化合物和多不饱和酸作为天然化合物或其半合成衍生物的药品因其在许多病理状况如炎症、癌症和皮肤疾病中的有用性而受到研究关注。黄酮类化合物应用的局限性在于其对细胞的低生物利用度、渗透性和溶解性。在本研究中,白杨素与n-3和n-6脂肪酸的共轭产生了更强的MT抑制剂,对其活性具有协同抑制作用。