page_title: Biological aspects of fluorine
section_title: Biochemistry
hierarchical_section_title: Biological aspects of fluorine / Biochemistry
caption_attribution_description: Afrikaans: Gifblaar, 'n suider-Afrikaanse plant wat fluoroasetaat produseer om dit van beweiding te beskerm English: a poison leaf (ratbane, Dichapetalum cymosum, gifblaar). The plant is African and has naturally made fluorocetate, a poison, to ward off animals.
context_page_description: Fluorine may interact with biological systems in the form of fluorine-containing compounds. Though elemental fluorine is very rare in everyday life, hundreds of fluorine-containing compounds occur naturally as minerals, medicines, pesticides, and materials. Naturally occurring organofluorine compounds are extremely rare, yet man-made fluoride compounds are common: for example, twenty percent of all commercialized pharmaceuticals contain fluorine, including Lipitor and Prozac. In many contexts, fluorine-containing compounds are harmless or even beneficial to living organisms; in others, they are toxic.
  Aside from their use in medicine, man-made fluorinated compounds have also played a role in several noteworthy environmental concerns. Chlorofluorocarbons, once major components of numerous commercial aerosol products, have proven damaging to Earth's ozone layer and resulted in the wide-reaching Montreal Protocol; though in truth the chlorine in CFCs is the destructive actor, fluorine is an important part of these molecules because it makes them very stable and long-lived. Similarly, the stability of many organofluorine compounds has raised the issue of biopersistence.
context_section_description: Biologically synthesized organofluorines are few in number, although some are widely produced. The most common example is fluoroacetate, with an active poison molecule identical to commercial "1080". It is used as a defense against herbivores by at least 40 green plants in Australia, Brazil, and Africa; other biologically synthesized organofluorines include ω-fluoro fatty acids, fluoroacetone, and 2-fluorocitrate. In bacteria, the enzyme adenosyl-fluoride synthase, which makes the carbon–fluorine bond, has been isolated. The discovery was touted as possibly leading to biological routes for organofluorine synthesis.
  Fluoride is considered a semi-essential element for humans: not necessary to sustain life, but contributing (within narrow limits of daily intake) to dental health and bone strength. Daily requirements for fluorine in humans vary with age and sex, ranging from 0.01 mg in infants below 6 months to 4 mg in adult males, with an upper tolerable limit of 0.7 mg in infants to 10 mg in adult males and females. Small amounts of fluoride may be beneficial for bone strength, but this is an issue only in the formulation of artificial diets. (See also fluoride deficiency.)
caption: South Africa's gifblaar is one of the few organisms that naturally produce fluorine compounds
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