Literature search and data collection

This review was conducted using a structured literature search and predefined inclusion criteria to identify studies reporting IC50 values for captopril-derived NDM-1 inhibitors. Studies were included if they met all the following criteria: 1) Biological inhibitory activity assays were performed on NDM-1; 2) The compounds investigated were clearly mentioned in the title or abstract as captopril derivatives, captopril-inspired derivatives or captopril-based derivatives; 3) The inhibitory concentrations (IC50) of captopril derivatives are reported clearly; 4) Original peer-reviewed scholarly articles that are published in English. Studies were excluded if they met any of the following criteria: 1) Biological inhibitory activity assays were not performed on NDM-1 specifically; 2) Reviews, editorials, or mechanistic studies without IC50 data.

The search was performed across PubMed, Google Scholar and Europe PMC and included literature published until February 2026. The search strategy combined free-text terms of interest, including the biological target and the inhibitor scaffold, using Boolean operators (AND/OR). The key search terms were NDM-1, New Delhi metallo-beta-lactamase-1, metallo-beta-lactamase, captopril, captopril derivatives, and captopril analogues. The search strategy was modified to suit the syntax and search interfaces of the respective databases. Titles and abstracts were screened to identify relevant studies, followed by full-text evaluation based on the inclusion criteria. Study selection and data extraction were performed by a single reviewer (the author).

The database search revealed a total of 376 records: 46 in PubMed, 132 in Google Scholar and 198 in Europe PMC. After eliminating 175 duplicate records, 201 unique records remained for screening titles and abstracts. Of these, 190 were eliminated as apparently irrelevant. The remaining eleven reports were retrieved. and were screened to determine eligibility. Following full-text assessment, five articles were excluded. Finally, six studies were found to fit the inclusion criteria and have been incorporated in the review for systematic SAR analysis. The study selection process is summarized in Figure 1.

Figure 1.: Flow diagram of the literature search and study selection process for studies included in the review