Antimycobacterial agent-12 (Compound Ec42) is a Platensimycin derivative and acts as a dual inhibitor of KasA and KasB. It demonstrates minimum inhibitory concentrations (MIC) of 2 μg/mL against Staphylococcus aureus ATCC 29213, 2 μg/mL against Mycobacterium smegmatis, and 4 μg/mL against its isoniazid-resistant strains. In a Mycobacterium smegmatis-infected mouse model, Antimycobacterial agent-12 exhibits excellent antimycobacterial activity, making it a valuable tool for tuberculosis research.