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Wyświetlanie 1-1 z 1
Tytuł:
Droga pod słońce. Wczesna historia witaminy D
The route against the sun. Early history of vitamin D
Autorzy:
Wicha, J.
Powiązania:
https://bibliotekanauki.pl/articles/172567.pdf
Data publikacji:
2012
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
witamina D
biosynteza i żywienie
sterole
badanie struktury
światło ultrafioletowe
dieta przeciwkrzywicza
historia witaminy D
vitamin D
biosynthesis
nutrition
sterols
structural investigations
ultraviolet light
antirachitic diet
Opis:
Two natural products are called „vitamin D”: (1) vitamin D3 which is biosynthesized in humans and animals and (2) vitamin D2 which is generated in photochemical rearrangement of a sterol of fungy – ergosterol (Fig. 1 and 2). The vitamins D are further metabolized (Scheme 1) first into 25-hydroxy- and then into 1.,25-dihydroxy derivatives in various tissues. The compounds control the calcium transport and act as a cell growth regulator important for tumor prevention. The early history of vitamin D stems from outburst of rickets at the beginning of the industrialization era. Rickets was a child bond disease that often led to a permanent disability. A comprehensive description of the rickets was presented by D. Whistler ( 1619–1684) and then F. Glisson (1597–1677) and coauthors. Jędrzej Śniadecki ( 1768–1838) was the first who associated the rickets with the sunlight. In his book “On the Physical Education of Children” Śniadecki stated that exposition of a child’s body to a direct action of sunlight is the most efficient method for the prevention and the cure of rickets (Illustrations 1 and 2). T. A. Palm in 1890 observed that the rickets is rare in countries where sunshine is abundant and prevalent whenever there is a little of sunlight. The first experimental evidence on the sunlight effects in rickets were presented by J. R aczyński in 1912 who postulated that the sunlight affects metabolic processes in blood related to calcium transport (Illustration 3 and 4). E. Mellanby showed (1919) that the disease is connected to the lack of certain dietary factors and he recommended the use of cod liver – oil. K. Huldschinsky experimentally proved that UV irradiation cures the rickets. The Mellanby’s and Huldschinsky’s observations were confirmed by clinical studies in 1922. E.V. McCollum has developed efficient methods for “biological analysis” of food and named anti-rachitic factor as vitamin D.H. Steenbock and A.F. Hess in 1924 found independently that various food products gain anti-rachitic properties after being irradiated with a UV lamp. A.F. Hees and A. Windaus showed that irradiation of ergosterol affords a product with high anti-rachitic activity. In 1919 the first structure for cholesterol has been proposed by A. Windaus (Scheme 2, Fig. 3) and then with contribution of H. Wieland it was modified to the “Wieland-Windaus” structure (1928, Nobel Price lectures, Fig. 4). O. Diels’ investigation on dehydratation of cholesterol (Fig. 5) and J.D. Bernal’s crystallographic measurements of ergosterol challenged the Wieland-Windaus structure. Finally, the correct structure for cholic acid and sterols was deduced by O. Rosenheim and H. King (Fig. 6). In 1932 crystalline vitamin D2 was prepared in the Windaus laboratory (Scheme 3). In 1935 vitamin D3 was isolated from a fish-oil and the same compound was synthesized from cholesterol (Illustration 5). The structure of vitamin D2 was elucidated by Windaus in 1935 (Illustration 6) and confirmed by X-ray studies in 1948. Scientific contributions of Adolf Windaus are associated with his highest ethical standards and non-conformist political position in the national-socialist age.
Źródło:
Wiadomości Chemiczne; 2012, 66, 7-8; 671-696
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-1 z 1

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