|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
Scientific journal is a periodical publication intended to further progress of science, usually by reporting novel research. There are thousands of scientific journals in publication, and many more have been published at various points in the past. Most journals are highly specialized, although some of the oldest journals publish articles and scientific papers across a wide range of scientific fields. Scientific journals contain articles that are peer reviewed, to ensure that articles meet the journal's standards of quality, and scientific validity. The publication of the results of research is an essential part of the scientific method. If they are describing experiments or calculations, they must supply enough details that an independent researcher could repeat the experiment or calculation to verify the results. Each such journal article becomes part of the permanent scientific record.