L-mimosine is an L-alpha-amino acid that is propionic acid substituted by an amino group at position 2 and a 3-hydroxy-4-oxopyridin-1(4H)-yl group at position 3 (the 2S-stereoisomer). It a non-protein plant amino acid isolated from Mimosa pudica. It has a role as an EC 1.14.18.1 (tyrosinase) inhibitor and a plant metabolite. It is a member of 4-pyridones and a non-proteinogenic L-alpha-amino acid. It is functionally related to a propionic acid. It is a conjugate acid of a L-mimosine(1-). L-mimosine is a naturally occurring plant amino acid and iron chelator that arrests the cell cycle in the late G(1) phase, prevents the initiation of DNA replication. Mimosine disrupts elongation of the replication fork by impairing deoxyribonucleotide synthesis, it has antiproliferative and antifibrotic effects on adult cardiac fibroblasts.