Undecaprenyl phosphate (Und-P) (Und-P)

Undecaprenyl phosphate, also known as bactoprenol phosphate, is a critical 55-carbon isoprenoid lipid carrier essential for the biosynthesis of the bacterial cell wall (PubChem CID 6433164). It functions as a membrane-bound shuttle that transports hydrophilic precursors, such as the N-acetylmuramic acid (NAM) and N-acetylglucosamine (NAG) building blocks of peptidoglycan, across the cytoplasmic membrane (Manat et al., 2014, Microbial Drug Resistance). Once these precursors are delivered to the external side of the membrane for polymerization, the resulting undecaprenyl pyrophosphate must be dephosphorylated back to its monophosphate form to be reused in subsequent transport cycles (PubMed ID: 25130115). This recycling process is a major vulnerability in bacterial metabolism and is the primary target of the antibiotic bacitracin, which binds to the pyrophosphate intermediate and prevents its conversion back to the active monophosphate form (StatPearls, Bacitracin). Because this lipid carrier is indispensable for bacterial survival and lacks a direct human counterpart, it represents a highly effective target for antimicrobial therapy, particularly against Gram-positive pathogens (Nature Reviews Microbiology, 2005). Beyond peptidoglycan, it is also involved in the synthesis of other cell surface polysaccharides like teichoic acids and O-antigens (UniProt). Therapeutic challenges include the high nephrotoxicity of systemic agents targeting this pathway, which often limits their clinical use to topical applications (NIH LiverTox). Research continues into novel compounds that can sequester the lipid carrier directly to overcome resistance mechanisms (Nature Communications, 2017).

Other names

Bactoprenol phosphateC55-isoprenyl phosphateUndecaprenyl monophosphateBactoprenol monophosphateC55-P

Inhibition of undecaprenyl pyrophosphate dephosphorylation, which prevents the regeneration of the active undecaprenyl phosphate carrier required for cell wall precursor transport (StatPearls, Bacitracin).