25694-37-5Relevant academic research and scientific papers
Montmorillonite clay catalysis I: An efficient and convenient procedure for preparation of 5(6)/5'(6')-unsaturated 3β,3'β-disteryl ethers
Li,Li,Guo,Jin
, p. 2497 - 2502 (1996)
In the presence of montmorillonite K 10, 5(6)-unsatured sterols (1) were heated at refluxing temperature in dichloromethane to provide 5(6)/5'(6')-unsaturated 3β,3'β-disteryl ethers (4) in 69-73% yield. The mechanism of the reaction was discussed.
Characterisation of non-polar dimers formed during thermo-oxidative degradation of β-sitosterol
Sosińska, Ewa,Przybylski, Roman,Hazendonk, Paul,Zhao, Yuan Yuan,Curtis, Jonathan M.
, p. 464 - 474 (2013)
Thermo-oxidative degradation of sterols at temperature typical for frying leads to the formation of oxidised derivatives, fragmented sterols and oligomers. Recent research on sterol oxidation focuses mainly on the oxysterol derivatives formation to the exclusion of compounds with high molecular mass. The aim of this work was to decipher the chemical structure of non-polar dimers formed during β-sitosterol oxidation at 180 °C in the presence of oxygen. The dimer fraction was separated by size-exclusion chromatography (SEC) after pre-fractionation on silica gel. The chemical structure of the dimers was assessed by 1D and 2D NMR, IR, Raman and MS spectroscopies. NMR data confirmed that the predominant non-polar dimer formed during β-sitosterol oxidative degradation has a configuration of 3β,3β′-disitosteryl ether. Data from IR and Raman spectroscopies further proved it chemical structure. Applied analytical techniques also confirmed presence of dimers with different configuration than disteryl ethers.
Synthesis and search for 3β,3′β-disteryl ethers after high-temperature treatment of sterol-rich samples
Bus, Katarzyna,Ofiara, Karol,Sitkowski, Jerzy,Szterk, Arkadiusz,Zmys?owski, Adam
, (2020/06/08)
It has been proven that at increased temperature, sterols can undergo various chemical reactions e.g., oxidation, dehydrogenation, dehydration and polymerisation. The objectives of this study are to prove the existence of dimers and to quantitatively analyse the dimers (3β,3′β-disteryl ethers). Sterol-rich samples were heated at 180 °C, 200 °C and 220 °C for 1 to 5 h. Quantitative analyses of the 3β,3′β-disteryl ethers were conducted using liquid extraction, solid-phase extraction and gas chromatography coupled with mass spectrometry. Additionally, for the analyses, suitable standards were synthetized from native sterols. To identify the mechanism of 3β,3′β-disteryl ether formation at high temperatures, an attempt was made to use the proposed synthesis method. Additionally, due to the association of sterols and sterol derivatives with atherosclerosis, preliminary studies with synthetized 3β,3′β-disteryl ethers on endothelial cells were conducted.
SYNTHESIS OF TRITERPENE AND STEROID GLYCOSIDES
Uvarova, Nina I.,Atopkina, Lyubov N.,Elyakov, Georgi B.
, p. 33 - 42 (2007/10/02)
The glycosylation of cholesterol, β-sitosterol, 28-O-acetylbetulin, and betulin with acylated glycosyl halides in the presence of Hg(OAc)2, Hg(CN)2, CdCO3, Ag2O, Ag2CO3, and HgO + HgBr2 usually gives acylated αβ-glycosides accompanied by acetates, ethers, and bromo and unsaturated derivatives of the initial alcohols.The use of Hg(CN)2 gave mainly β anomers (40-87percent), whereas α anomers preponderated when Hg(OAc)2 was the catalyst.When there was a deficiency of hydrogen halide acceptor and in the presence of the acidic catalyst HgBr2*HBr, the β anomer, produced initially, underwent anomerisation.Cholesteryl α-D-glucopyranoside tetra-acetate (48percent) was obtained by anomerisation of the β anomer.
