• Erythromycin Estolate packaged and labeled.

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SKU: E003

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Erythromycin estolate, a derivative of Erythromycin, is the lauryl sulfate salt of the proprionic ester of Erythromycin.  It acts as a bacteriostatic agent, and has a role as an enzyme inhibitor.  Erythromycin estolate is freely soluble in organic solvents but practically insoluble in water.

For other Erythromycin products, click here.

    CAS Number


    Molecular Formula

    C40H71NO14 · C12H26SO4

    Molecular Weight

    1056.39 g/mol

    Mechanism of Action

    Macrolide antibiotics inhibit bacterial growth by targeting the 50S ribosomal subunit preventing peptide bond formation and translocation during protein synthesis. Resistance to Erythromycin is commonly attributed to mutations in 50S rRNA preventing erythromycin binding allowing the cell to synthesize proteins free of error.

    Storage Conditions

    Light sensitive

    Tariff Code



    Erythromycin is a broad-spectrum antibiotic commonly targeting targeting Gram-negative and Gram-positive bacteria. It is also effective against Mycoplasmas including Mycoplasma pneumoniae.


    Eukaryotic Cell Culture Applications

    Cytotoxicity of of erythromycin estolate was compared to other macrolides in cultured human non-malignant Chang liver cells and was found the most toxic when compared to Erythromycin, erythromycin-11,12-cyclic carbonate, roxithromycin, clarithromycin and azithromyciin (Viluksel et al, 1996).

    Gene expression microarrays can prioritize lead compounds in drug development research.  In vitro primary rat hepatocytes were exposed to 11 known hepatotoxicants in low-density DNA microarrays with 59 genes known as toxic and metabolic markers for transcription profiling.  Erythromycin estolate was found to cluster in the group with drugs that induced cholestatis.  Gene expression data correlated well with the literature (de Longueville et al, 2003).

    Microbiology Applications

    Erythromycin Estolate is commonly used in clinical in vitro microbiological antimicrobial susceptibility tests (panels, discs, and MIC strips) against Gram-positive, Gram-negative, and Mycoplasmas species.  Medical microbiologists use AST results to recommend antibiotic treatment options for infected patients.  Representative MIC values include:

    • Mycoplasma pneumoniae 0.0019 µg/mL – 0.0078 µg/mL
    • Legionella pneumophila 0.008 µg/mL – 1 µg/mL
    • For a  complete list of Erythromycin MIC values, click here.





    White crystalline powder


    Actinomycete saccha

    Water Content (Karl Fischer)


    Melting Point

    132-138 °C


    Not less than 610 u/mg (dried basis)



    de Longueville, F et al (2003) Use of a low-density microarray for studying gene expression patterns induced by hepatotoxicants on primary cultures of rat hepatocytes. Toxicolog. Sci. 75(2):378-392 PMID 12883083

    Lovmar, M and Tenson T (2003) The Mechanism of action of macrolides, Lincosamides and Streptogramin B reveals the nascent peptide exit path in the ribosome. J. Molec. Microbiol. 330(5):1005-1014 PMID 12860123

    Potthast H, Schug B, Elze M, Schwerdtle R, Blume H (1995) Comparison of the bioavailabilities of erythromycin estolate and erythromycin ethylsuccinate dry suspension preparations in steady state. Pharmazie 50(1):56-60 PMID 7886126

    Viluksel M, Vainio PJ, Raimo K, Tuominen RK (1996) Cytotoxicity of macrolide antibiotics in a cultured human liver cell line, J. Antimicrob. Chemother. 38 (3):465–473 PMID 8889721

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