1912-54-5Relevant articles and documents
3β-Acetoxy-6-nitrocholest-5-ene: Crystal structure, thermal, optical and dielectrical behavior
Shamsuzzaman,Mashrai, Ashraf,Khanam, Hena,Mabkhot, Yahia Nasser,Frey, Wolfgang
, p. 219 - 225 (2014)
3β-Acetoxy-6-nitrocholest-5-ene (2) has been synthesized from 3β-acetoxycholest-5-ene (1). We provided an analysis of the compound by means of FT-IR, FT-Raman, NMR and X-ray crystallography. In addition microstructural, thermal, optical and dielectrical properties were also investigated. The compound 2 crystallizes in the monoclinic space group P2 1 with cell dimensions, a = 15.7729 (13) A?, b = 9.8933 (8) A?, c = 17.8070(14) A?, α = 90.00, β = 96.176(4), γ = 90.00. The powder X-ray diffraction (PXRD) of the compound was recorded to ascertain phase homogeneity. The SEM micrograph showed the presence of brick shaped, elongated nitrocholestane particles with 177.12 × 25.53 × 5.69 μm dimensions. Thermogravimetric analysis showed stability of the compound up to 200 C. The dielectrical studies showed that with increase in frequency, the dielectric constant decreases and becomes almost constant at high frequencies.
Oxidation of cholesterol and O-protected derivatives by the environmental pollutant NO2?
Zalewski,Nathanael,White,Wille
, p. 4060 - 4063 (2016)
Exposure of O-protected and free cholesterol 1 to NO2· under exclusion of water leads to nitroimine nitrates 2 through a non-radical mechanism, which reveals the high susceptibility of the π system to oxidative damage. In the presence of moisture the reaction leads to 6-nitrocholesterols 3, which result from hydrolysis and oxidation of 2.
Synthesis of spermidinylcholestanol and spermidinylcholesterol, squalamine analogues
Choucair, Bassima,Dherbomez, Michel,Roussakis, Cristos,El Kihel, La?la
, p. 11477 - 11486 (2004)
Several novel squalamine-related polyaminosterols are reported. The synthesis of 7α-N-[3N-(4-aminobutyl)aminopropyl]aminocholestanol I, 6α-N-[3N-(4-aminobutyl)aminopropyl]aminocholestanol II, 7α and 7β-N-[3N-(4-aminobutyl)aminopropyl]aminocholesterol (III and IV), was accomplished from cholesterol, they provide the first examples in which spermidine is introduced in the B steroidal ring. These molecules showed comparable antibacteria and fungi activities to squalamine, and were cytotoxic on a human non-small cell bronchopulmonary carcinoma line (NSCLC-N6). Therefore, these molecules with antibiotic and cytotoxic activities are promising for immune-compromised patients in cancer chemotherapy. Graphical Abstract.
Synthesis and in vitro antibacterial activity of novel steroidal (6R)-spiro-1,3,4-thiadiazoline derivatives
Khan, Salman A.,Asiri, Abdullah M.
, p. 1452 - 1457 (2012)
Novel steroidal (6R)-spiro-1,3,4-thiadiazoline derivatives were synthesized by the cyclization of steroidal thiosemicarbazones with acetic anhydride, screened in vitro against antibacterial activity using disc-diffusion method and the minimum inhibitory concentration. The results showed that steroidal thiadiazoline derivatives exhibited better antibacterial activity than the steroidal thiosemicarbazone derivatives. Chloro and acetoxy substituents on the 3β-position of the steroidal thiadiazoline ring increased the antibacterial activity. Among all the compounds, compound 7 and 8 were found better inhibitors of both types of bacteria (Gram-positive and Gram-negative) as compared to the respective drug amoxicillin. All the synthesized compounds were well characterized by spectroscopic methods such as IR, 1H-NMR, 13C-NMR mass, and elemental analysis and their stereochemistry was also discussed.
Chemoselective epoxidation of cholesterol derivatives on a surface-designed molecularly imprinted Ru-porphyrin catalyst
Muratsugu, Satoshi,Baba, Hiroshi,Tanimoto, Tatsuya,Sawaguchi, Kana,Ikemoto, Satoru,Tasaki, Masahiro,Terao, Yosuke,Tada, Mizuki
, p. 5114 - 5117 (2018/05/26)
A new molecularly imprinted Ru-porphyrin complex catalyst on a SiO2 support was designed, prepared, and characterized in a step-by-step manner for the C5C6 epoxidation of cholesterol derivatives. High chemoselectivity for the C5C6 epoxidation of cholesterol derivatives without protecting the 3-position OH group and other oxidizable functional groups was achieved on the molecularly imprinted catalyst.