the in vitro and in vivo antibacterial activities of 6-o-methylerythromycin a ( te-031 , a-56268 , or clarithromycin ) and 6,11-di-o-methylerythromycin a ( te-032 ) have been compared with those of erythromycin a ( em ) and josamycin ( jm ) .
C0055856
clarithromycin
C0014806
erythromycin