Alkaloids exert considerable physiological effects on humans and animals and are used in therapeutics as narcotics and have a calming effect. Some alkaloids are strong poisons, for example, curare, which has the ability to paralyze the nervous system. Alkaloids are considered to be an insecticide defense means in plants. Some alkaloids, for example nicotine, play a role in enzymatic oxidation-reduction processes. The alkaloid-producing plants are dicotyledons, and to a lesser extent monocotyledons and cryptogamas. Generally, a plant contains several alkaloids. The alkaloid content depends on the age of the plant, region, climate and season. Algae and bryophytes do not produce alkaloids. They are rare in mushrooms (ergotamine), in pteridophytes (nicotine in Equisetum, coniine in Lycopodium spores) and in gymnosperms (ephedrine). In the angiosperms, some families are reputed by their high contents in alkaloids: Solanaceae (solanine, nicotine, hyoscyamine, atropine), Rubiaceae (caffeine, quinine), and Papaveraceae (morphine, papaverine, codeine, narceine, etc.). The most important alkaloids are: coniine, nicotine, tropane, atropine, cocaine, quinine, papaverine, morphine, codeine, strychnine, caffeine, and others [3,8]. Alkaloids have a great structural diversity and are synthesized mainly in Solanaceae and Fabaceae. For example, pepper (Capsicum annuum), contains alkamide alkaloids such as affinin (spilanthol) and capsaicin , potato (Solanum tuberosum) contains several toxic and teratogenic glycoalkaloids , and lupin (Lupinus angustifolius) contains a large number of quinolizidine alkaloids, notably 13 α-hydroxy lupanine and lupanine. Highly unsaturated planar quaternary alkaloids possess the ability to intercalate with DNA  and modify the nucleotide sequences . Tamarindus indica (Fabaceae) aqueous pulp extract was found to have antimicrobial effect against E. coli, S. aureus, and P. aeruginosa, but not against Salmonella typhi . Zapoteca portoricensis leaf extract has antibacterial action against Gram-positive bacteria S. aureus, E. coli, Streptococcus pyogenes, Klebsiella pneumoniae, and Gram-negative P. aeruginosa .