L-arginine degradation agmatine biosynthesis L-arginine degradation via ADC pathway PMID:12641342 pathway PMID:15656789 KEGG:map01100 KEGG:map00330 arginine decarboxylase pathway UPa:UPA00186 The decarboxylation of L-arginine by arginine decarboxylase produces agmatine. Agmatine is a metabolic intermediate in the biosynthesis of putrescine and higher polyamines (spermidine and spermine). Recent studies indicate that agmatine can have several important biochemical effects in humans, ranging from effects on the central nervous system to cell proliferation in cancer and viral replication. amine and polyamine biosynthesis