Berberine is an alkaloid derived from tyrosine. The roots contain the bitter alkaloid berberine. The bark contains an alkaloid, Berberine. The chemical constituents include isoquinolone alkaloids, especially berberine. Some alkaloids are colored, like berberine (yellow) and sanguinarine (orange). The roots of both species contain berberine, a known anti-tumor alkaloid. The stem and the roots contain quaternary alkaloids, such as berberine, palmatine, magnoflorine and columbamine. The rhizomes of "Coptis chinensis" contain the isoquinoline alkaloids berberine, palmatine, and coptisine among others. Intensively studied DNA intercalators include berberine, ethidium bromide, proflavine, daunomycin, doxorubicin, and thalidomide. Goldenseal contains the isoquinoline alkaloids hydrastine, berberine, berberastine, hydrastinine, tetrahydroberberastine, canadine and canalidine. The active compound, berberine, affects cell wall integrity and ergosterol biosynthesis. Traditional Chinese herbal medicines, like berberine downregulate E-selectin. The primary bioactive ingredient in "Coscinium fenestratum" is berberine, but also palmatine and jatrorrhizine. Berberine is usually found in the roots, rhizomes, stems, and bark. However, a natural substance Berberine is available as a dietary supplement.