1452-34-2Relevant academic research and scientific papers
Addressable Cholesterol Analogs for Live Imaging of Cellular Membranes
Rakers, Lena,Grill, David,Matos, Anna L.L.,Wulff, Stephanie,Wang, Da,B?rgel, Jonas,K?rsgen, Martin,Arlinghaus, Heinrich F.,Galla, Hans-Joachim,Gerke, Volker,Glorius, Frank
, p. 952 - 12,961 (2018)
Cholesterol is an essential component of most biological membranes and serves important functions in controlling membrane integrity, organization, and signaling. However, probes to follow the dynamic distribution of cholesterol in live cells are scarce and so far show only limited applicability. Herein, we addressed this problem by synthesizing and characterizing a class of versatile and clickable cholesterol-based imidazolium salts. We show that these cholesterol analogs faithfully mimic the biophysical properties of natural cholesterol in phospholipid mono- and bilayers, and that they integrate into the plasma membrane of cultured and primary human cells. The membrane-incorporated cholesterol analogs can be specifically labeled by click chemistry and visualized in live-cell imaging experiments that show a distribution and behavior comparable with that of endogenous membrane cholesterol. These results indicate that the cholesterol analogs can be used to reveal the dynamic distribution of cholesterol in live cells. Cholesterol is an important component of biological membranes, but probes recording its dynamic intracellular distribution are scarce. Rakers et al. developed cholesterol-derived imidazolium salts mimicking properties of natural cholesterol. Following specific labeling via click chemistry, one of the cholesterol analogs was shown to incorporate into cellular membranes equivalent to endogenous cholesterol.
Ruthenium nanoparticles ligated by cholesterol-derived NHCs and their application in the hydrogenation of arenes
Rakers, Lena,Martínez-Prieto, Luis M.,López-Vinasco, Angela M.,Philippot, Karine,Van Leeuwen, Piet W. N. M.,Chaudret, Bruno,Glorius, Frank
, p. 7070 - 7073 (2018/07/05)
Herein we present ruthenium nanoparticles (Ru-NPs) stabilized with two rigid NHC ligands derived from cholesterol. The obtained nanoparticles were fully characterized and applied in the hydrogenation of various aromatic compounds under mild conditions. Interestingly, the more bulky ligand gives a slightly lower ligand coverage and a faster catalyst.
Efficient synthesis of novel A-ring-substituted 1,2,3- triazolylcholestanederivatives via catalytic azide-alkyne cycloaddition
Kadar, Zalan,Frank, Eva,Schneider, Gyula,Molnar, Judit,Zupko, Istvan,Koti, Janos,Schoenecker, Bruno,Woelfling, Janos
, p. 279 - 296 (2013/09/24)
A simple and convenient synthetic route is reported for the formation of novel 2α-triazolylcholestane derivatives. The scheme involves transformation of the starting cholestanone to the corresponding azido compound and efficient conversions of 2α-azido-5α-cholestan-3-one (3) with various terminal alkynes through use of the 'click' chemistry approach. Finally, the oxo group of these heterocyclic steroidal derivatives was reduced, and the resultant mixtures of epimeric triazolyl alcohols were separated. The antiproliferative activities of the synthesized 2-triazolyl-3-ketones against three human cancer cell lines were screened. Nevertheless, only a few of the tested compounds exerted moderate cell-growth inhibition. ARKAT-USA, Inc.
A New α-Iodination of Ketones Using Iodine-Ammonium Cerium(IV) Nitrate in Alcohol or Acetic Acid
Horiuchi, C. Akira,Kiji, Shinji
, p. 421 - 426 (2007/10/03)
The direct α-iodination of various ketones using iodine-ammonium cerium(IV) nitrate in acetic acid or alcohol gave the corresponding α-iodo ketones in high yields. The effect of cerium salt on the iodination of ketones, and the iodination of 5α-cholestan-3-one using several methods are also discussed. In the reaction of 3,3,5-trimethylcyclohexanone and unsymmetrical ketones, such as 2-hexanone and 2-heptanone, using methanol, ethanol, 1-propanol, and 2-propanol, the regioselective iodination product was obtained. In the case of bromination, the reaction of ketones with bromine and ammonium cerium(IV) nitrate also yielded the corresponding α-bromo ketones.
STEREOCHIMIE-LVII ETUDE STEREOCHIMIQUE ET CINETIQUE DE LA BROMATION D'ESTERS ET D'ETHERS ENOLIQUES STEROIDIQUES
Calvet, Alain,Jozefowitz, Marcel,Levisalles, Jacques
, p. 103 - 115 (2007/10/02)
Absolute rates of bromination were measured for two series of derivatives of steroidal ketones 3, enol acetates 1 and enol methyl ether 2.Axial substituents exhibited a large effect on rates, which increased by 15,000 fold on going from (X=CH3; Y=CN) to (X=Y=H).From the bromide ion effect it was concluded that the first step (formation of an intermediate bromonium ion) was reversible and that the second step (formation of haloketones 4 or 5 or of haloacetals 8 or 9) was slow compared to the first step.The intermediate was concluded to be a highly unsymmetrical bromonium ion rather than a plain oxocarbenium ion.
Process for the preparation of androstane-3,17-dione derivatives
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, (2008/06/13)
A process for the preparation of androstane-3,17-dione compounds of the formula STR1 wherein X is 1,2-methylene or 1- or 2-methyl, comprises fermenting a sterol of the formula STR2 wherein X is as above and R1 is the hydrocarbon residue of 8-10 carbon atoms, of a sterol, with a microorganism culture capable of effecting the side chain degradation of sterols.
