has role erythromycin A erythromycin A(1+) erythromycin A cation CHEBI:64268 An erythromycin cation that is the conjugate acid of erythromycin A, arising from protonation of the tertiary amino group on the 3,4,6-trideoxy-3-(dimethylamino)-β-<small>D</small>-<i>xylo</i>-hexopyranosyl residue; major species at pH 7.3. chebi_ontology erythromycin A erythromycin cation bacterial metabolite