Alkaloids are natural nitrogen-containing compounds produced by plants and microbes. These molecules, such as morphine and quinine, are important human medicines. Alkaloids are typically polycyclic in nature. While the polycyclic characteristics are important for their bioactivities, these features impede their chemical syntheses in the laboratory and their applications as pharmaceuticals.
from Geochemistry News -- ScienceDaily http://ift.tt/2lDrQEP