Alkaloids are basically one of the largest groups of plant-specialized metabolites as a result of their diversity of structures and biosynthetic pathways. In 1804, morphine was the the first alkaloid to be isolated in crystalline form from opium poppy. Since the discovery of morphine, more than 20,000 alkaloids have been isolated. Low molecular weight compounds are alkaline due to the presence of a heterocyclic ring containing a nitrogen atom. These compounds are mostly produced by flowering plants and some animals. Some plant families like Papaveraceae, Ranunculaceae, Amaryllidaceae, Solanaceae, Apocynaceae, Asteraceae, Berberidaceae, Boraginaceae, Fabaceae are very rich in alkaloids. Alkaloids as such are an interesting group of compounds with a broad spectrum of overall effectiveness, and undesirable and desirable effects on animal and human organisms. They have antibacterial, antimitotic, anti-inflammatory, analgesic, local anesthetic, hypnotic, psychotropic and antitumor effects. Finally, alkaloids also include neuroactive molecules, such as caffeine and nicotine, and act as stimulants and drugs, some of which include codeine, morphine, vinblastine and vincristine.