Results 161 to 170 of about 13,198 (194)

Photochemical transformations of 7-dehydrocholesterol

Russian Journal of Applied Chemistry, 2009
Photochemical transformations of 7-dehydrocholesterol were performed with a two-lamp experimental circulation installation equipped with a ferrioxalate actinometer and were monitored by UV spectroscopy and high-performance liquid chromatography. The quantum yields of the overall conversion of 7-dehydrocholesterol at wavelengths of 254, 313, and 365 nm ...
Z. L. Grigoryan, A. I. Martiryan, L. A. Nersesyan, Sh. A. Markaryan   +3 more
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Synthesis of 7-dehydrocholesterol acetate

Chemistry of Natural Compounds, 1973
It has been shown that 7-oxocholesterol acetate (III) can easily be converted into 7-dehydrocholesterol acetate by the Bamford-Stevens reaction. The yield of desired product amounts to 79% calculated on the (III) or 63% calculated on the cholesterol acetate.
E. V. Yablonskaya, M. G. Segal
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Light‐Induced Activation of 7‐Dehydrocholesterol

Angewandte Chemie International Edition in English, 1982
AbstractThe complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 846.
Karlheinz Schmitt‐Rau, Manfred Wilk
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Ozonolysis of 7-dehydrocholesterol acetate peroxide

Tetrahedron Letters, 1979
Abstract Secodione 3 and hemiacetal 4 from ozonolysis of peroxide 2 were obtained. A tentative mechanism of their formation is proposed.
J. Gumułka, W.J. Szczepek, Z. Wielogórski   +2 more
openaire   +1 more source

HPLC analysis of desmosterol, 7‐dehydrocholesterol, and cholesterol

Lipids, 1989
AbstractA simple and sensitive method to analyzed mixtures of desmosterol, 7‐dehydrocholesterol and cholesterol is described. The method involves the oxidative conversion of the sterols with cholesterol oxidase, followed by high performance liquid chromatographic (HPLC) analysis.
E H, Goh, S M, Colles, K D, Otte
openaire   +2 more sources

The preparation of radioactive 7-dehydrocholesterol

Steroids, 1963
The preparation of radioactive 7-dehydrocholesterol (5,7-cholestadien-3 BETA -ol) by procedures that utilize milligram quantities of cholesterol as starting material is described. The isocaproate adaptation of the allylic bromination of cholesterol with N-bromosuccinimide followed by dehydrobromination was employed and found to be amenable to a scale ...
B.D. Kulkarni, G. Blondin, W.R. Nes
openaire   +1 more source

Secretory production of 7‐dehydrocholesterol by engineered Saccharomyces cerevisiae

Biotechnology Journal, 2023
AbstractBackground7‐Dehydrocholesterol (7‐DHC) can be directly converted to vitamin D3 by UV irradiation and de novo synthesis of 7‐DHC in engineered Saccharomyces cerevisiae has been recognized as an attractive substitution to traditional chemical synthesis.
Xia Ke, Zi‐Hao Pan, Hong‐Fei Du, Yi Shen, Ji‐Dong Shen, Zhi‐Qiang Liu, Yu‐Guo Zheng   +6 more
openaire   +2 more sources

Skin content of 7-dehydrocholesterol in patients with malabsorption

Nutrition, 1997
The mechanism for the development of vitamin D deficiency in patients with malabsorption remains unclear. We wished to examine the hypothesis that one factor was a reduced skin content of 7-dehydrocholesterol, the precursor for the formation of vitamin D in the presence of ultraviolet radiation.
C R, Paterson, J P, Moody, C R, Pennington   +2 more
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Engineered yeast for efficient de novo synthesis of 7‐dehydrocholesterol

Biotechnology and Bioengineering, 2022
AbstractThe synthesis of vitamin D3 precursor 7‐dehydrocholesterol (7‐DHC) by microbial fermentation has much attracted attention owing to its advantages of environmental protection. In this study, Saccharomyces cerevisiae was engineered for a de novo biosynthesis of 7‐DHC.
Lisha Qu, Xiang Xiu, Guoyun Sun, Chenyang Zhang, Haiquan Yang, Yanfeng Liu, Jianghua Li, Guocheng Du, Xueqin Lv, Long Liu   +9 more
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Photometabolism of 7-dehydrocholesterol to previtamin D3 in skin

Biochemical and Biophysical Research Communications, 1977
Abstract The photometabolism of [3α-3H]-7-dehydrocholesterol in skin was studied in groups of rats exposed to ultraviolet irradiation. The major photolytic product was identified as previtamin D3 by its identical migration with authentic previtamin D3 on high-pressure liquid chromatography.
M F, Holick, J E, Frommer, S C, McNeill, N M, Richtand, J W, Henley, J T, Potts   +5 more
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