Bicyclomycin

Bicyclomycin is an antibiotic. Bicyclomycin exhibits selective antibacterial activity against Gram-negative bacteria such as Escherichia coli and Klebsiella spp., with no cross-resistance. Bicyclomycin is applicable to the research of infectious diseases^[1][2]. In Vitro:Bicyclomycin (6-25 μg/mL; 2 h) induces dose-dependent morphological changes (cell elongation, spheroplast formation) in actively growing cells of E. coli strain 15 THU and the highly sensitive E. coli strain ATCC 27166^[1].
Bicyclomycin (25-100 μg/mL; 0-60 min) inhibits RNA and protein synthesis in proliferating E. coli 15 THU cells, but does not affect their DNA or lipid synthesis^[1].
At a concentration of 100 μg/mL over 0-45 min, bicyclomycin exerts a stronger inhibitory effect on bound lipoprotein synthesis (inhibition rate of approximately 95%) than on free lipoprotein (inhibition rate of approximately 60%) and envelope protein synthesis (inhibition rate of approximately 50%) in histidine-starved E. coli 15 THU cells, with no effect on cytoplasmic protein synthesis^[1].
Bicyclomycin exhibits selective moderate antibacterial activity against specific Gram-negative bacteria (Escherichia coli NIHJ JC-2, Klebsiella pneumoniae ST-101, Salmonella typhosa T-287, Shigella flexneri 1a-2 W-A), with an MIC of 25 mcg/mL; it shows only weak activity against Sarcina lutea PCI-100 (MIC 250 mcg/mL); and it has no activity against other tested Gram-positive bacteria, Gram-negative bacteria, mycobacteria, fungi, or yeasts^[2]. In Vivo:The acute toxicity of Bicyclomycin via intravenous injection exceeds 2 g/kg, while its acute toxicity via subcutaneous, oral and intraperitoneal administration exceeds 4 g/kg in mice^[2].