Microbial Natural Products Targeting the Mycobacterium tuberculosis Complex: Toward the Discovery of Novel Anti-Tubercular Agents.

Tuberculosis (TB) remains one of the most significant global public health challenges, as it represents the world's leading infectious cause of death. The clinical efficacy of currently available anti-TB drugs is increasingly compromised due to the growing prevalence of antibiotic-resistant strains, side effects, and prolonged treatment times. This scenario highlights the urgent need to identify new anti-TB drugs with alternative mechanisms of action and improved anti-TB activity and bioavailability. In this context, natural products derived from microorganisms represent a key source of chemical diversity for drug discovery. Actinomycetes, fungi, and other environmental microbes produce a wide range of secondary metabolites with broad antimicrobial activity. These compounds can interfere with essential bacterial structures and processes, including membrane integrity, redox homeostasis, protein synthesis, and DNA replication. This review aims to evaluate new microbial natural products for their antibacterial activity, focusing on their efficacy, mechanisms of action, chemical nature, and potential clinical applications, with the aim of informing the development of new anti-TB agents.