negatively regulates polyamine biosynthetic process negative regulation of biosynthetic process regulation of polyamine biosynthetic process negative regulation of amine metabolic process biological regulation negative regulation of polyamine biosynthetic process https://github.com/geneontology/go-ontology/issues/29814 Any process that stops, prevents, or reduces the frequency, rate or extent of polyamine biosynthesis. Polyamine biosynthesis is the chemical reactions and pathways resulting in the formation of polyamines, any organic compound containing two or more amino groups. ew 2025-03-11T19:55:32Z GO:0170066 biological_process