Targeting the 's Thymidylate Monophosphate Kinase for the Identification of Novel Antimalarial Natural Compounds.

Recent reports of resistance to artemisinin-based combination drugs necessitate the need to discover novel antimalarial compounds. The present study was aimed at identifying novel antimalarial compounds from natural product libraries using computational methods. is highly dependent on the pyrimidine biosynthetic pathway, a pathway responsible for the production of pyrimidines, and the parasite lacks the pyrimidine salvage enzymes. The thymidylate monophosphate kinase (TMPK) is an important protein necessary for rapid DNA replication; however, due to its broad substrate specificity, the protein is distinguished from its homologs, making it a suitable drug target. Compounds from AfroDB, a database of natural products originating from Africa, were screened virtually against TMPK after filtering the compounds for absorption, distribution, metabolism, excretion, and toxicity (ADMET)-acceptable compounds with FAF-Drugs4. Thirteen hits with lower binding energies than thymidine monophosphate were selected after docking. Among the thirteen compounds, ZINC13374323 and ZINC13365918 with binding energies of -9.4 and -8.9 kcal/mol, respectively, were selected as plausible lead compounds because they exhibited structural properties that ensure proper binding at the active site and inhibitory effect against TMPK. ZINC13374323 (also called aurantiamide acetate) is known to exhibit anti-inflammatory and antiviral activities, and ZINC13365918 exhibits antileishmanial activity. Furthermore, aurantiamide acetate, which is commercially available, is a constituent of , the herb from which artemisinin was derived. The compound also shares interactions with several residues with a potent thymidine analog inhibitor of TMPK. The anti-plasmodial activity of aurantiamide acetate was evaluated , and the mean half-maximal inhibitory concentration (IC) was 69.33 μM when synchronized 3D7 culture was used as compared to IC > 100 μM with asynchronized culture. The significance of our findings within the context of malaria treatment strategies and challenges is discussed.