A class of heterocyclic compounds that include a three-ring fused structure. Both aromatic or non-aromatic ring structures are included in this category.
Also Known As:
Heterocyclic Compounds, 3-Ring; Fused Heterocyclic Compounds, Three-Ring; Heterocyclic Cpds, 3 Ring; Three Ring Heterocyclic Compounds; Fused Heterocyclic Compounds, Three Ring; Heterocyclic Compounds, 3 Ring