51982-45-7Relevant academic research and scientific papers
Photo-conversion of two epimers (20R and 20S) of pregna-5,7-diene-3β, 17α, 20-triol and their bioactivity in melanoma cells
Zmijewski, Michal A.,Li, Wei,Zjawiony, Jordan K.,Sweatman, Trevor W.,Chen, Jianjun,Miller, Duane D.,Slominski, Andrzej T.
scheme or table, p. 218 - 228 (2009/04/14)
Pregna-5,7-dienes and their hydroxylated derivatives can be formed in vivo when there is a deficiency in 7-dehydrocholesterol (7-DHC) Δ-reductase function, e.g., Smith-Lemli-Opitz syndrome (SLOS). Ultraviolet B (UVB) radiation induces photoconversion of 7-DHC to vitamin D3, lumisterol3 and tachysterol3. Two epimers (20R and 20S) of pregna-5,7-diene-3β,17α,20-triol (4R and 4S, respectively) were synthesized and their UVB photo-conversion products identified as corresponding 9,10-secosteroids with vitamin D-like and tachysterol-like structures, and 5,7-dienes with inverted configuration at C-9 and C-10 (lumisterol-like). The number and character of the products and the dynamics of the process were dependent on the UVB dose. At high UVB doses, the formation of multiple oxidized derivatives of the primary products, and the formation of 5,7,9(11)-triene, were observed. The production of vitamin D-like, tachysterol-like and lumisterol-like derivatives was also observed in human skin treated with 4R and 4S, and subjected to UV irradiation, as shown by RP-HPLC. Newly synthesized compounds inhibited melanoma growth in dose dependent manner, and some of them showed equal or higher potency than 1,25(OH)2D3. In summary, we have characterized for the first time the products of UV induced conversion of pregna-5,7-diene-3β,17α,20-triols and documented that the newly synthesized compounds have antiproliferative properties against melanoma cells.
Cyclodextrin-catalyzed extraction of fluorescent sterols from monolayer membranes and small unilamellar vesicles
Ohvo-Rekilae, Henna,Akerlund, Bjoern,Slotte, J. Peter
, p. 167 - 178 (2007/10/03)
This study examined the kinetics of sterol desorption from monolayer and small unilamellar vesicle membranes to 2-hydroxypropyl-β-cyclodextrin. The sterols used include cholesterol, dehydroergosterol (ergosta-5,7,9,(11),22- tetraen-3β-ol) and cholestatrienol (cholesta-5,7,9,(11)-trien-3β-ol). Desorption rates of dehydroergosterol and cholestatrienol from pure sterol monolayers were faster (3.3-4.6-fold) than the rate measured for cholesterol. In mixed monolayers (sterol: 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine 30:70 mol%), both dehydroergosterol and cholestatrienol desorbed faster than cholesterol, clearly indicating a difference in interfacial behavior of these sterols. In vesicle membranes desorption of dehydroergosterol was slower than desorption of cholestatrienol, and both rates were markedly affected by the phospholipid composition. Desorption of sterols was slower from sphingomyelin as compared to phosphatidylcholine vesicles. Desorption of fluorescent sterols was also faster from vesicles prepared by ethanol-injection as compared to extruded vesicles. The results of this study suggest that dehydroergosterol and cholestatrienol differ from cholesterol in their membrane behavior, therefore care should be exercised when experimental data derived with these probes are interpreted. (C) 2000 Elsevier Science Ireland Ltd.
Synthesis of Steroid Phosphates via Monomeric Metaphosphate
Ramirez, Fausto,Marecek, James F.,Yemul, Shrishailam S.
, p. 1417 - 1420 (2007/10/02)
Dihydrogen phosphate esters derived from steroids having one, two, and three conjugated or nonconjugated double bonds have been conveniently prepared by a procedure that probably involves the monomeric metaphosphate anion as an intermediate.The source of metaphosphate is a 1:2 molar mixture of (1-phenyl-1,2-dibromoethyl)phosphonic acid and diisopropylethylamine (B) in a 0.05 M dichloromethane solution at 20 deg C: (1) C6H5C(Br)(PO3H2)CH2Br + 2B + ROH -> ROPO3H(-)BH(+) + C6H5CBr=CH2 + Br(-)BH(+); (2) ROPO3H(-)BH(+) + HCl -> ROPO3H2 + BH(+)Cl(-).Yields of steroid dihydrogen phosphates with on e or two double bonds range from 65percent to 75percent.The labile Δ5,7,9-cholestatriene 3β-O-phosphate can be isolated in a pure state, although in lower yield (46percent), by this procedure.
