Antimicrobial, Antibiofilm, and Anticancer Activities with Molecular Docking and ADME Properties of l‑Alanine Methyl Ester and l‑Valine Methyl Ester

Abstract

The increasing prevalence of antimicrobial resistance and biofilm-related infections represents a serious global health problem that limits the effectiveness of current therapeutic agents. Also, the increasing burden of cancer worldwide is one of the biggest challenges that we face. Both situations necessitate the investigation of potential new bioactive molecules. In recent years, amino-acid-based compounds have become a focal point of interest as versatile candidates in the development of both antimicrobial and anticancer agents, thanks to their biocompatibility, structural diversity, and targeted interaction capabilities. Therefore, in this study, the experimental antimicrobial activity of l-alanine methyl ester and l-valine methyl ester was evaluated against the reference strains Candida albicans ATCC 10231, Escherichia coli ATCC 35218, Klebsiella pneumoniae MTCC 109, Pseudomonas aeruginosa ATCC 27853, and Staphylococcus aureus ATCC 25923. Antimicrobial tests and biofilm inhibitory effects were assessed by broth dilution and crystal violet binding assays, respectively. According to our findings, the amino acid esters exhibited microorganism-dependent antimicrobial and antibiofilm activities, with l-alanine methyl ester generally showing greater antimicrobial activity than l-valine methyl ester across most tested strains, particularly against E. coli and K. pneumoniae. In biofilm assays, both esters similarly demonstrated strain- and concentration-dependent effects, with the highest inhibition again observed against E. coli and K. pneumoniae. In addition, the anticancer efficacy of the esters was evaluated using the MTT assay, annexin V staining, the TUNEL assay, and the colony-forming assay with lung (A549) and hepatocellular (HepG2) cancer cells. Both esters demonstrated significant antiproliferative properties and effectively suppressed long-term colony formation in cancer cells. Importantly, they also maintained a robust safety profile by having a minimal impact on healthy HDFs. Furthermore, molecular docking calculations were performed on the esters examined among the identified targets using the AutoDock Vina program, and their potential drug-like properties and ADME characteristics were investigated. Overall, it can be said that the amino acid esters we examined have significant pharmaceutical potential and will contribute to the advancement of new strategies involving amino-acid-ester-based synthesizable molecules and drug development studies.