... > chemical entity > molecular entity > main group molecular entity > p-block molecular entity > pnictogen molecular entity > nitrogen molecular entity > ammonium compound > organoammonium salt > quaternary ammonium salt > methacholine chloride

... > chemical entity > molecular entity > main group molecular entity > p-block molecular entity > pnictogen molecular entity > nitrogen molecular entity > organonitrogen compound > quaternary nitrogen compound > quaternary ammonium salt > methacholine chloride

... > chemical entity > molecular entity > main group molecular entity > p-block molecular entity > carbon group molecular entity > organic molecular entity > heteroorganic entity > organonitrogen compound > quaternary nitrogen compound > quaternary ammonium salt > methacholine chloride