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.

Teriflunomide is the principal active metabolite of leflunomide?an approved therapy for rheumatoid arthritis and?multiple sclerosis.

Lucenin-2 is a natural C-glucoside compound belonging to the flavonoid class.