Protoporphyrin IX, in the metabolism of porphyrin, is created by the enzyme protoporphyrinogen oxidase.

2-Hydroxyemodin is an active metabolite of emodin in the hepatic microsomes. Emodin is an anthraquinone present in fungal metabolites and constituent of rhubarb. 2-Hydroxyemodin proves to be mutagenic to Salmonella typhimurium TA1537 in the absence of activation system.

IK-930 is an orally active TEAD inhibitor (EC50 < 0.1 μM) with potent potency.