Secondary Metabolites
Alkaloids represent a type of secondary metabolite produced by plants. They are heterocyclic compounds that contain one or more nitrogen atoms. Alkaloids are carefully regulated chemical components that protect the plants that produce them. Through their metabolic processes, alkaloids have a high affinity for acetylcholine receptors and function as effective neurotoxins in animals that attempt to feed on the plants. These compounds ensure the plant will survive and reproduce.
Pyrrolizidine Alkaloids
Pyrrolizidine alkaloids are toxins found in a number of plant species. These alkaloids typically affect not only wildlife, but humans and their livestock as well. Pyrrolizidine alkaloids may cause fatal damage to the liver. Humans or animals may ingest them when eating contaminated corn. Crotolaria, a weed that contains these alkaloids, occurs in corn crops and sometimes accidentally mixes with the crop during harvest. The pyrrolizidine alkaloids could survive the various processes involved in making bread, including the milling and baking of the contaminated corn.
Encoded Enzymes
Alkaloids are nitrogenous organic molecules. Through their metabolic activity, these compounds perform a number of biochemical reactions that benefit their host. As part of the alkaloid's metabolic process, gene-encoded enzymes are transported to wounds in the leaves of the plant to effect healing.
Ergot Alkaloids
These alkaloids are compounds produced by fungi that attack grains during their growing period. Claviceps and related fungi species replace the ovaries of the developing corn seed with masses of fungal tissue, termed ergots or sclerotia. This mass of hard tissue is dark in color and composed of ergot alkaloids. The fungus gains entry into the plant from ergots in the soil, which develop and undergo biosynthesis by utilizing nutrients from the host. Ergots are harvested with the grain and can potentially find their way into corn products, unless eliminated through screening. Ergots that are ingested cause acute poisoning that ranges from nausea to causing abortions in pregnant females. Ergotamine and ergovaline are two of the common alkaloids associated with these conditions.