has primary input or output alkaloid metabolic process alkaloid metabolic process biological_process alkaloid metabolism GO:0009820 The chemical reactions and pathways involving alkaloids, nitrogen containing natural products which are not otherwise classified as peptides, nonprotein amino acids, amines, cyanogenic glycosides, glucosinolates, cofactors, phytohormones or primary metabolites (such as purine or pyrimidine bases). organonitrogen compound metabolic process