A macrolide antibiotic; active against Gram-positive and Gram-negative bacteria, including C. trachomatis and C. pneumoniae (MICs = 0.125-0.5 and 0.25-1 μg/ml, respectively); inhibits growth of multidrug resistant P. falciparum in vitro (IC50s = 0.5 nM for both Dd2 and 7G8 strains); eradicates P. berghei infection in mice when administered in a four-dose series at 100 mg/kg