s-thanatin

**S-thanatin** is a synthetic derivative of thanatin, an antimicrobial peptide originally isolated from the insect Podisus maculiventris. S-thanatin differs from native thanatin by having a serine residue at position 15 instead of threonine. It adopts a β-hairpin structure stabilized by a disulfide bond and demonstrates potent broad-spectrum antibacterial activity, particularly against Gram-negative bacteria, including multidrug-resistant (MDR) strains such as carbapenem-resistant Klebsiella pneumoniae. The mechanism of action involves disrupting the bacterial outer membrane, lowering plasma endotoxin levels, and targeting the bacterial lipopolysaccharide transport (Lpt) system, which is essential for outer membrane biogenesis. S-thanatin shows efficacy in animal models, improving survival rates and reducing bacterial titers in infected tissues[1][11][13].