3d image of urobilin skeletal formula

urobilin urochrome urine yellow color tetrapyrrole urobilinogen degradation products cyclic heme biliverdin bilirubin stercobilin feces obstructive jaundice excretion porphyria homogentisate alkaptonuria metabolite metabolism biosynthesis cycle mechanism pathway path catabolism biosynthetic intermediate biogenesis substrate precursor synthesis derivative bioprecursor metabolic enzyme endogenous contractor molecule molecular formula skeletal structural structure biochemistry biomolecule bioactive biochemical 3d