ChEBI Get Ontology Parents

Get the ontology parents (is-a / has-role ancestors) of a ChEBI compound, navigating UPWARD in the chemical classification hierarchy (the symmetric counterpart of ChEBI_get_ontology_children). ChEBI uses a rich ontology with relationships like 'is a', 'has role', 'has functional parent', and 'is conjugate base/acid of'. Example: CHEBI:15377 (water) parents include 'mononuclear parent hydride' and 'inorganic hydroxy compound' (is a), and 'human metabolite', 'amphiprotic solvent' (has role).