Background: The MurA enzyme, enolpyruvyl UDP-N-acetylglucosamine transferase, is one of the targeted proteins by antibiotics for effective treatment of diseases provided by pathogenic bacteria. It plays a key role in the cell wall biosynthesis of Gram-positive bacteria such as Enterococcus faecalis. Butein is a flavonoid that showed antioxidant and anticancer activities, but recently it is a promising antibacterial agent and reported can inhibit E. faecelis, Eschericia coli, and Mycobacterium tuberculosis. It was isolated from medicinal plants, including Sarang Semut (Myrmecodia pendans). However, the molecular mechanism of butein inhibits bacteria that is no clear.

Objective: This study aims to predict the molecular action of the butein against MurA, catalyzing the first step of peptidoglycan biosynthesis.

Material and Methods: Butein isolation used a combinational separation technique and characterization using spectroscopic methods. Then, in silico method used was virtual screening using programs including Autodock Vina in PyRx, protein. plus, and ligplots. Butein and UDP-N-acetylglucosamine (UNAG as a positive control) act as ligand were subject binding to 3KQJ MurA as protein. To evaluate in vitro antibacterial activity, we used the Kirby-Bauer method.

Results: Butein from M. pendans is a potential compound to inhibit the MurA with binding affinity - 7.6 kcal.mol-1. It is lower than UNAG but higher than Fosfomycin as a MurA inhibitor. Butein attaches to MurA in the same position as UNAG so that it concludes that both is a competitive inhibitor. Meanwhile, in vitro study showed that butein inhibits the E. faecalis growth with inhibit zone of 8.37 mm at 1 mg/ml.

Conclusion: Butein as a potent antibacterial agent through blocking MurA enzyme in cell wall formation.

背景：MurA 酶，烯醇丙酮酸 UDP-N-乙酰葡糖胺转移酶，是抗生素的靶向蛋白之一，可有效治疗病原菌提供的疾病。它在革兰氏阳性菌如粪肠球菌的细胞壁生物合成中起关键作用。Butein 是一种黄酮类化合物，具有抗氧化和抗癌活性，但最近它是一种很有前途的抗菌剂，据报道可以抑制粪肠球菌、大肠杆菌和结核分枝杆菌。它是从药用植物中分离出来的，包括 Sarang Semut (Myrmecodia pendans)。但是，butein抑制细菌的分子机制尚不清楚。

目的：本研究旨在预测丁二醇对 MurA 的分子作用，催化肽聚糖生物合成的第一步。

材料和方法：Butein 分离使用组合分离技术和使用光谱方法表征。然后，使用的计算机方法是使用包括 Autodock Vina in PyRx、蛋白质在内的程序进行虚拟筛选。加号和 ligplots。Butein 和 UDP-N-乙酰葡糖胺（UNAG 作为阳性对照）作为配体被作为蛋白质与 3KQJ MurA 结合。为了评估体外抗菌活性，我们使用了 Kirby-Bauer 方法。

结果：来自 M. pendans 的 Butein 是一种潜在的化合物，可以抑制 MurA，具有结合亲和力 - 7.6 kcal.mol-1。作为 MurA 抑制剂，它低于 UNAG 但高于磷霉素。Butein 以与 UNAG 相同的位置依附于 MurA，因此它得出结论，两者都是竞争性抑制剂。同时，体外研究表明，butein 抑制粪肠球菌的生长，抑制区为 8.37 mm，浓度为 1 mg/ml。

结论：Butein 通过阻断细胞壁形成中的 MurA 酶而成为一种有效的抗菌剂。