|Alkaloids are naturally occurring chemical compounds containing basic nitrogen atoms. The name derives from the word alkaline is due to nitrogen containing base. Alkaloids are produced by a large variety of organisms, including bacteria, fungi, plants, and animals and are part of the group of natural products, also called secondary metabolites. Many alkaloids are purified from crude extracts by acid-base extraction. Many alkaloids are toxic to other organisms. They often have pharmacological effects and are used as medications, as recreational drugs, or in entheogenic rituals. Examples are the local anesthetic and stimulant cocaine, the stimulant caffeine, nicotine, the analgesic morphine, or the antimalarial drug quinine. Some alkaloids have a bitter taste. The classification of the alkaloids is complex and is by a set of rules like structure and other chemical features of the alkaloid molecule, its biological origin, as well as the biogenetic origin where known. The groups are Pyridine group, Pyrrolidine group, Tropane group, Indolizidine group, Quinoline group, Isoquinoline group, Phenanthrene alkaloids, Phenethylamine group, Indole group: Purine group and terpenoid group
Journal articles are most often Primary Research Articles. However, they can also be Review Articles. These types of articles have different aims and requirements. Sometimes, an article describes a new tool or method.
Because articles in scientific journals are specific, meticulously cited and peer-reviewed, journal databases are the best place to look for information on previous research on your species. Without a background in the field, journal articles may be hard to understand - however, you do not need to understand an entire article to be able to get valuable information from it.