Background: Shikimate pathway is essential for tubercular bacillus but it is absent in mammals. Therefore, Shikimate kinase and other enzymes in the pathway are potential targets for the development of novel anti-tuberculosis drugs.

Objective: In the present study, Shikimate kinase is selected as the target for in silico screening of phytochemicals with an aim to discover a novel herbal drug against Mycobacterium tuberculosis (Mtb).

Methods: A structure-based drug discovery approach is undertaken for the execution of the objective. Virtual screening of phytochemical database NPACT against the target, Shikimate kinase (PDB ID 3BAF), is carried out followed by toxicity and drug-likeness filtration. Finally, a lead, narirutin was selected for in vitro anti-tubercular study.

Results: Narirutin, present in citrus fruits, emerges as the lead. It is considered to be non-toxic with predicted high LD50 value, 12000 mg/kg body weight. The phytochemical is tested for its antitubercular activity in vitro. It has MIC99 62.5 μg/mL against the MtbH37Rv strain.

Conclusion: This is the first-ever report to show anti-tuberculosis potency of narirutin.

背景：莽草酸途径对于结核杆菌是必不可少的，但在哺乳动物中不存在。因此，莽草酸激酶和该途径中的其他酶是开发新型抗结核药物的潜在靶点。

目的：在本研究中，莽草酸激酶被选为植物化学物质计算机筛选的靶标，旨在发现一种新型的抗结核分枝杆菌 (Mtb) 草药。

方法：采用基于结构的药物发现方法来实现目标。针对目标莽草酸激酶 (PDB ID 3BAF) 对植物化学数据库 NPACT 进行虚拟筛选，然后进行毒性和药物相似性过滤。最后，选择了领先的纳瑞丁用于体外抗结核研究。

结果：存在于柑橘类水果中的 Narirutin 成为主要成分。它被认为是无毒的，预计 LD50 值很高，为 12000 毫克/公斤体重。在体外测试了植物化学物质的抗结核活性。它对 MtbH37Rv 菌株的 MIC99 为 62.5 μg/mL。

结论：这是有史以来第一份显示纳瑞汀抗结核效力的报告。