All
 D03 Heterocyclic Compounds D006571 +
 D03.066 Acids, Heterocyclic D000147 +
 D03.132 Alkaloids D000470 +
 D03.605 Heterocyclic Compounds, Bridged-Ring D006572 +
 D03.383 Heterocyclic Compounds, 1-Ring D006573 +
 D03.438 Heterocyclic Compounds, 2-Ring D006574 +
 D03.494 Heterocyclic Compounds, 3-Ring D006575 +
 D03.549 Heterocyclic Compounds with 4 or More Rings D006576 +
 D03.661 Heterocyclic Oxides D006577 +