Berberine, an isoquinoline alkaloid with a bright yellow color, is easily seen in most of the herb materials when found in significant amounts. Among Chinese herbs, the primary sources for berberine are phellodendron and coptis. Similar isoquinoline alkaloids (jateorrhizine, coptisine, palmatine, and columbamine) in these two herbs also have a yellowish color. Among these alkaloids, berberine has been used as a dye; it is also known as “natural yellow 18”, being one of about 35 yellow dyes from natural sources. Coptis and phellodendron have been used in China for treating gastrointestinal diseases with reported success; applications include acute gastroenteritis, cholera, and bacillary dysentery. Recent clinical trials have yielded conflicting results as to which of the disease organisms causing intestinal symptoms are responsive to berberine.
Tests of the antiseptic action of berberine against bacteria, viruses, and amoebas, have shown a range of activity levels from potent to mild suppression. Many new alkaloids and new synthetic pathways of this family are reported. The current work proposes to synthesize intermediate analogues that will facilitate the total synthesis of berberine alkaloids.