ChEBI: Erythromycin A is an erythromycin that consists of erythronolide A having 2,6-dideoxy-3-C-methyl-3-O-methyl-alpha-L-ribo-hexopyranosyl and 3,4,6-trideoxy-3-(dimethylamino)-beta-D-xylo-hexopyranosyl residues attahced at positions 4 and 6 respectively. It is an erythromycin and a cyclic ketone. It is functionally related to an erythronolide A. It is a conjugate base of an erythromycin A(1+).