Editing Biotin (section)

==History==
{{Further|Vitamin#History}}
In 1916, W. G. Bateman observed that a diet high in raw egg whites caused toxic symptoms in dogs, cats, rabbits, and humans.<ref>{{cite journal| vauthors = Bateman WG |date=June 1916|title=The Digestibility and Utilization of Egg Proteins|journal=Journal of Biological Chemistry|volume=26|pages=263–91|doi=10.1016/S0021-9258(18)87458-0|doi-access=free|url=https://archive.org/download/digestibilityuti00bate/digestibilityuti00bate_bw.pdf}}</ref> By 1927, scientists such as Margarete Boas and [[Helen Parsons]] had performed experiments demonstrating the symptoms associated with "egg-white injury." They had found that rats fed large amounts of egg whites as their only protein source exhibited neurological dysfunction, [[Alopecia|hair loss]], dermatitis, and eventually, death.<ref>{{cite journal | vauthors = Boas MA | title = The Effect of Desiccation upon the Nutritive Properties of Egg-white | journal = The Biochemical Journal | volume = 21 | issue = 3 | pages = 712–724.1 | date = 1927 | pmid = 16743887 | pmc = 1251968 | doi = 10.1042/bj0210712 }}</ref><ref>{{cite journal | vauthors = Parsons HT, Kelly E | journal = The Journal of Biological Chemistry | volume = 100 | date = 1933 | title = The Character of the Dermatitis-Producing Factor in Dietary Egg White as Shown by Certain Chemical Treatments | issue = 11 | pages = 377–379 | pmid = 7005763 | doi = 10.1111/j.1753-4887.1980.tb05948.x | s2cid = 86107167 }}</ref>

In 1936, Fritz Kögl and Benno Tönnis documented isolating a yeast growth factor in a journal article titled "{{Lang|de|Darstellung von krystallisiertem biotin aus eigelb|italic=no}}." (Representation of crystallized biotin from egg yolk).<ref>{{cite journal|last=Kögl and Tönnis|date=1936 |volume=242|issue=1–2|pages=43–73|doi=10.1515/bchm2.1936.242.1-2.43|title=Über das Bios-Problem. Darstellung von krystallisiertem Biotin aus Eigelb. 20. Mitteilung über pflanzliche Wachstumsstoffe|journal=Hoppe-Seyler's Zeitschrift für Physiologische Chemie}}</ref> The name ''biotin'' derives from the Greek word {{Transliteration|grc|bios}} ('to live') and the suffix "-in" (a general chemical suffix used in organic chemistry).<ref name=Etymology /> Other research groups, working independently, had isolated the same compound under different names. Hungarian scientist [[Paul Gyorgy]] began investigating the factor responsible for egg-white injury in 1933 and in 1939, was successful in identifying what he called "Vitamin H" (the H represents {{Lang|de|Haar und Haut}}, German for 'hair and skin').<ref>{{cite journal|last=György|first=P|date=December 1939|title=The Curative Factor (vitamin H) for Egg White Injury, with Particular Reference to Its Presence in Different Foodstuffs and in Yeast|url=http://www.jbc.org/content/131/2/733|journal=Journal of Biological Chemistry|volume=131|issue=2|pages=733–44|doi=10.1016/S0021-9258(18)73468-6|doi-access=free|access-date=January 10, 2021|archive-date=January 13, 2021|archive-url=https://web.archive.org/web/20210113092132/https://www.jbc.org/content/131/2/733|url-status=live}}</ref><ref>{{cite journal|vauthors=György P,Kuhn R, Lederer E|date=December 1939|title=Attempts to Isolate the Factor (vitamin H) Curative of Egg White Injury|url=http://www.jbc.org/content/131/2/745|journal=Journal of Biological Chemistry|volume=131|issue=2|pages=745–59|doi=10.1016/S0021-9258(18)73469-8|doi-access=free|access-date=January 10, 2021|archive-date=January 14, 2021|archive-url=https://web.archive.org/web/20210114101141/https://www.jbc.org/content/131/2/745|url-status=live}}</ref> Further chemical characterization of vitamin H revealed that it was water-soluble and present in high amounts in the liver.<ref>{{cite journal|last1=Birch|first1=TW|last2=György|first2=P|date=December 1939|title=Physicochemical Properties of the Factor (vitamin H) Curative of Egg White Injury|url=http://www.jbc.org/content/131/2/761|journal=Journal of Biological Chemistry|volume=131|issue=2|pages=761–66|doi=10.1016/S0021-9258(18)73470-4|doi-access=free|access-date=January 10, 2021|archive-date=January 14, 2021|archive-url=https://web.archive.org/web/20210114122012/https://www.jbc.org/content/131/2/761|url-status=live}}</ref> After experiments performed with yeast and ''Rhizobium trifolii'', West and Wilson isolated a compound they called co-enzyme R.<ref>{{cite journal | vauthors = West PM, Wilson PW | title = The Relation of "coenzyme R" to Biotin | journal = Science | volume = 89 | issue = 2322 | pages = 607–8 | date = June 1939 | pmid = 17751623 | doi = 10.1126/science.89.2322.607 | bibcode = 1939Sci....89..607W | s2cid = 30138816 }}</ref><ref>{{cite journal|vauthors=DuVigneaud V, Hofmann K, Melville DB, György P|date=August 1941|title=Isolation of Biotin (vitamin H) from Liver|url=http://www.jbc.org/content/140/2/643|journal=Journal of Biological Chemistry|volume=140|issue=2|pages=643–51|doi=10.1016/S0021-9258(18)51355-7|doi-access=free|access-date=January 10, 2021|archive-date=January 13, 2021|archive-url=https://web.archive.org/web/20210113113037/https://www.jbc.org/content/140/2/643|url-status=live}}</ref> By 1940, it was recognized that all three compounds were identical and were collectively given the name: biotin.<ref>{{cite journal | vauthors = György P, Rose CS, Hofmann K, Melville DB, DU Vigneaud V | title = A Further Note on the Identity of Vitamin H with Biotin | journal = Science | volume = 92 | issue = 2400 | pages = 609 | date = December 1940 | pmid = 17795447 | doi = 10.1126/science.92.2400.609 | bibcode = 1940Sci....92..609G }}</ref> Gyorgy continued his work on biotin and in 1941 published a paper demonstrating that egg-white injury was caused by the binding of biotin by [[avidin]].<ref>{{cite journal | vauthors = György P, Rose CS, Eakin RE, Snell EE, Williams RJ | title = Egg-White Injury as the Result of Nonabsorption or Inactivation of Biotin | journal = Science | volume = 93 | issue = 2420 | pages = 477–8 | date = May 1941 | pmid = 17757050 | doi = 10.1126/science.93.2420.477 | bibcode = 1941Sci....93..477G | jstor = 1668938 }}</ref><ref>{{cite journal | vauthors = Gyorgy P, Rose CS |date=1943|title=The Liberation of Biotin from the Avidin-Biotin Complex (AB)|journal=Experimental Biology and Medicine|volume=53|issue=1|pages=55–7|doi=10.3181/00379727-53-14183|s2cid=84419614}}</ref> Unlike for many vitamins, there is insufficient information to establish a recommended dietary allowance, so dietary guidelines identify an "adequate intake" based on best available science with the understanding that at some later date this will be replaced by more exact information.<ref name="DRItext"/><ref name=AustNZ/><ref name=EFSA2017 />

Using ''E. coli'', a biosynthesis pathway was proposed by Rolfe and Eisenberg in 1968. The initial step was described as a condensation of pimelyl-CoA and alanine to form 7-oxo-8-aminopelargonic acid. From there, they described a three-step process, the last being introducing a sulfur atom to form the tetrahydrothiophene ring.<ref>{{cite journal | vauthors = Rolfe B, Eisenberg MA | title = Genetic and biochemical analysis of the biotin loci of ''Escherichia coli'' K-12 | journal = Journal of Bacteriology | volume = 96 | issue = 2 | pages = 515–24 | date = August 1968 | pmid = 4877129 | pmc = 252325 | doi = 10.1128/JB.96.2.515-524.1968 }}</ref>