Abstract Urease is a metallo-protein in which two nickel (Ni) atoms are present at the active site. It is found in all the organisms such as, bacteria, fungi, plants, and in algae. Urease enzymes are also involved in catalyzing the hydrolysis of urea into CO2 and NH3. Urease is a virulence factor found in various pathogenic bacteria. It is essential in colonization of a host organism and in maintenance of bacterial cells in tissues. Due to its enzymatic activity, urease has a toxic effect on human cells. Current research work aimed to purify the three di-naphthodiospyrols namely; 5,4 -dihydroxy-1-methoxy-6,6 -dimethyl7,3-binaphthyl-1,4,5,8-tetraone (1), 5,8 -dihydroxy-5-methoxy-6,6-dimethyl-7,3-binaphthyl-1,4,1,4 -tetraone (2) and 8,5,8-trihydroxy-6,6-dimethyl-7,3-binaphthyl-1,4,1,4-tetraone (3) from the chloroform fraction of Diospyros lotus roots. The pure constituents (1-3) were evaluated for their urease inhibitory activity. Compounds (1-3) exhibited potent activity with IC50 value of 28.27 ± 1.68, 20.57 ± 2.00, 27.12 ± 2.45 µM respectively, when compared with standard thiourea (IC50 = 21.23 ± 0.12 µM). The pure isolated compounds (1-3) were also subjected to in silico studies to know their binding pattern with enzyme. The binding orientation and interactions with the important residues of urease enzyme revealed that the three compounds inactivate the enzyme activity by interacting with Ni bi-center as well as with the tailpiece residues.

中文翻译：

---

来自薯蓣的萘醌作为潜在的脲酶抑制剂：体外和计算机研究

摘要 脲酶是一种金属蛋白质，其活性位点存在两个镍 (Ni) 原子。它存在于所有生物体中，例如细菌、真菌、植物和藻类。脲酶也参与催化尿素水解成 CO2 和 NH3。脲酶是一种存在于各种病原菌中的毒力因子。它对于宿主生物的定殖和组织中细菌细胞的维持是必不可少的。由于其酶活性，脲酶对人体细胞具有毒性作用。目前的研究工作旨在提纯三种二萘二苯并吡喃；5,4-二羟基-1-甲氧基-6,6-二甲基7,3-联萘-1,4,5,8-四酮 (1), 5,8-二羟基-5-甲氧基-6,6-二甲基-7 ,3-binaphthyl-1,4,1,4-tetraone (2) 和 8,5,8-trihydroxy-6,6-dimethyl-7,3-binaphthyl-1,4,1, 来自 Diospyros 莲藕的氯仿部分的 4-四酮 (3)。评价纯成分 (1-3) 的脲酶抑制活性。与标准硫脲 (IC50 = 21.23 ± 0.12 µM) 相比，化合物 (1-3) 表现出有效的活性，IC50 值分别为 28.27 ± 1.68、20.57 ± 2.00、27.12 ± 2.45 µM。还对纯分离的化合物 (1-3) 进行了计算机模拟研究，以了解它们与酶的结合模式。结合方向和与脲酶重要残基的相互作用表明，这三种化合物通过与 Ni 双中心以及尾部残基相互作用使酶活性失活。与标准硫脲相比，分别为 45 µM (IC50 = 21.23 ± 0.12 µM)。还对纯分离的化合物 (1-3) 进行了计算机模拟研究，以了解它们与酶的结合模式。结合方向和与脲酶重要残基的相互作用表明，这三种化合物通过与 Ni 双中心以及尾部残基相互作用使酶活性失活。与标准硫脲相比，分别为 45 µM (IC50 = 21.23 ± 0.12 µM)。还对纯分离的化合物 (1-3) 进行了计算机模拟研究，以了解它们与酶的结合模式。结合方向和与脲酶重要残基的相互作用表明，这三种化合物通过与 Ni 双中心以及尾部残基相互作用使酶活性失活。