A semisynthetic glycopeptide antibiotic that inhibits the growth of Gram-positive bacteria; inhibits the growth of clinical isolates of MRSA, MSSA, VREF, VSRF, and other staphylococci, streptococci, and enterococci (MIC90s = ≤0.008-0.5 mg/L); inhibits growth of S. aureus in a neutropenic-mouse thigh model of infection (ED50 = 0.95 mg/kg for single dose); improves survival of mice in an inhalation model of B. anthracis Ames anthrax