Cytochrome P450scc (P450scc) catalyzes the cleavage of the side chain of both cholesterol and the vitamin D(3) precursor, 7-dehydrocholesterol. The aim of this study was to test the ability of human P450scc to metabolize ergosterol, the vitamin D(2) precursor, and define the structure of the major products. P450scc incorporated into the bilayer of phospholipid vesicles converted ergosterol to t...

Over a period of time, two vitamin D parent compounds were elucidated. Ergocalciferol (D2) is synthesized from ergosterol in many plants, whereas cholecalciferol (D3) is derived from 7-dehydrocholesterol in the skin of animals. Ultraviolet light transforms these compounds into 1, 25-diOH vitamin D3, the vitamin D metabolite generally considered the most active. Approximately 40 times more D2 is...

Sterols which have been identified in a transplantable preputial gland tumor are lanosterol, 24,25-dihydrolanosterol, 4cr-methylAs-cholestenol, A’-cholestenol, 7-dehydrocholesterol, and cholesterol (preceding paper (2)). Arranged in the above sequence, they suggest a possible pathway for the conversion of lanosterol to cholesterol. The studies presented in this report of acetate incorporation i...

We report that silver ion HPLC provides remarkable separations of C27 sterols differing only in the number or location of olefinic double bonds. This technique has been extended to LC-MS, analysis of purified components by GC, GC-MS, and 1H NMR, and to its use on a semipreparative scale. The application of this methodology for the demonstration of the catalysis, by rat liver microsomes, of the ...

Herewith a new process concept for synthesis is presented which combines both UV-photoirradiation and high-p,T intensification (photo-high-p,T) in continuous flow. The application of this procedure to Vitamin D3 synthesis promotes thermal shifting of the equilibrium from the reaction intermediate to the product. This is enabled by microreactors which allow operation under harsh conditions such ...

The selectivity of the antibiotic nystatin towards ergosterol compared to cholesterol is believed to be a crucial factor in its specificity for fungi. In order to define the structural features of sterols that control this effect, nystatin interaction with ergosterol-, cholesterol-, brassicasterol- and 7-dehydrocholesterol-containing palmitoyloleoylphosphocholine vesicles was studied by fluores...