## 3 Mechanisms of Action of Antimicrobial Compounds
aureus_ as shown in Table 2. By targeting these critical steps, plant-derived compounds effectively halt bacterial protein production, leading to growth arrest and cell death. V. Interfering with nucleic acid synthesis or expression: Plant compounds disrupt nucleic acid synthesis by targeting various stages of RNA and DNA production through multiple mechanisms. They can inhibit essential enzymes involved in replication and transcription [112]. Nucleic acids, including DNA and RNA, are essential for bacterial replication, transcription, and translation, making them key targets for antimicrobial action. As seen in Table 2, plant compounds such as berberine, andrographolide, and terpinene-4-ol disrupt these processes by inhibiting enzymes involved in DNA replication, RNA synthesis, or nucleic acid metabolism [6; 8; 9]. For instance, berberine interferes with DNA gyrase and topoisomerase IV, enzymes crucial for DNA replication and repair, while andrographolide inhibits RNA polymerase, halting transcription. Allicin inhibits DNA gyrase by preventing the formation of RNA and partially inhibiting the synthesis of DNA and proteins. This suggests that RNA is the primary target of allicin, which ultimately disrupts the processes necessary for bacterial growth and replication [11]. By targeting nucleic acid synthesis or expression, these plant-derived compounds effectively halt bacterial growth and reproduction, ultimately causing cell death. On the other hand, Table 2 provides information on the plant source, antimicrobial compounds, class, mechanism of action, concentration (\(\upmu\)g/mL), the pathogens against which they exhibit antimicrobial activity, and reference. This table shows information on different natural compounds obtained from plants that can be used against pathogenic bacteria. These compounds belong to several classes such as phenolics, terpen, alkaloids, and organosulfur compounds. They show various mechanisms of action against microorganisms, suggesting that they can affect different stages of the bacterial life cycle, such as cell membrane integrity, nucleic acid synthesis, and protein biosynthesis. For instance, Chelerythrine, an alkaloid found in _Toddalia asatica_, disrupts the cell membrane integrity and inhibits protein biosynthesis, thereby showing activity against _Staphylococcus aureus_ and Methicillin-resistant _S. aureus_. On the other hand, organosulfur compounds such as Allicin and Diallyl trisulfide from _Allium sativum_ interfere with nucleic acid synthesis and affect cell membrane integrity, respectively. Phenols, by contrast, mainly affect cell membrane integrity and, in some cases, inhibit quorum sensing. Ellagic acid, Gallic acid, and Punicalagin are some of the phenolic compounds that show antimicrobial properties, specifically against microorganisms such as _Salmonella Typhimurium_ and _S. aureus_. Additionally, some terpen, such as Terpinen-4-ol from _Cinnamumum camphora_ L. and Andrographolide from _Andrographis paniculata_, also exhibit antimicrobial activities by affecting nucleic acid synthesis, cell wall biosynthesis, and cell membrane integrity. Although the effective concentration varies between compounds and microorganisms, the data presentedin Table 2 suggest that these natural compounds have the potential to be developed as antimicrobial agents. However, it is important to consider that these studies are based on in vitro testing, and further investigation is required to determine their efficacy and safety in complex settings. Furthermore, bioavailability and toxicity should also be addressed in future studies to fully evaluate the therapeutic potential of these antimicrobial compounds obtained from plant sources.