noun
( -s )
Etymology: probably from porph yrin + -o- + bili- + -in + -o- + gen
: a dicarboxylic acid H 2 NCH 2 (C 4 H 2 N)(CH 2 COOH)CH 2 CH 2 COOH that is derived from pyrrole and formed from two molecules of delta-amino-levulinic acid, that is found in the urine in acute porphyria, and that on condensation of four molecules yields uroporphyrin and other porphyrins