- Chemical Name: Kanamycin monosulfate (a mixture of kanamycin A, B, and C sulfates)
- Molecular Formula:
- Kanamycin A: C₁₈H₃₆N₄O₁₁·H₂SO₄
- Kanamycin B: C₁₈H₃₇N₅O₁₀·H₂SO₄
- Molecular Weight:
- Kanamycin A sulfate: 582.58 g/mol
- Kanamycin B sulfate: 583.60 g/mol
- Appearance: White to off-white crystalline powder
- Solubility:
- Water: ~50 mg/mL (clear, colorless solution at 20 mg/mL)
- DMSO: Slightly soluble (~5 mg/mL)
- Ethanol: Insoluble (<1 mg/mL)
- Stability:
- Stable in dry form at room temperature
- Aqueous solutions stable at pH 2–9 for 24 hours
- Degrades in strong acids/bases or upon prolonged heating
- Mechanism of Action:
- Primary Target: 30S ribosomal subunit → disrupts protein synthesis
- Binds irreversibly to the 16S rRNA (A-site) → misreading of mRNA
- Bactericidal at high concentrations
- Spectrum of Activity:
- Gram-negative: Escherichia coli, Klebsiella, Enterobacter, Salmonella
- Gram-positive: Limited activity (some Staphylococcus strains)
- Mycobacteria: Mycobacterium tuberculosis (second-line drug)
- Resistance Mechanisms:
- Enzymatic modification: Aminoglycoside-modifying enzymes (e.g., aphA, aac, aad genes)
- Ribosomal mutation: Alterations in 16S rRNA (less common)
