566-28-9

Basic information

• Product Name: 7-KETOCHOLESTEROL
• Synonyms: 7-KETOCHOLESTEROL;5-CHOLESTEN-3BETA-OL-7-ONE;3BETA-HYDROXY-5-CHOLESTEN-7-ONE;(3-beta)-cholest-5-en-7-on;3-beta-hydroxy-cholest-5-en-7-on;3-beta-hydroxycholest-5-en-7-one;7-oxo-cholestero;7-oxocholesterol
• CAS NO: 566-28-9
• Molecular Formula: C₂₇H₄₄O₂
• Molecular Weight: 400.64
• Product Categories: Intermediates & Fine Chemicals;Pharmaceuticals;Steroids
• Mol File: 566-28-9.mol

Chemical Properties

• Melting Point: 158-160°C
• Boiling Point: 463.26°C (rough estimate)
• Flash Point: 218.5°C
• Appearance: /
• Density: 1.0044 (rough estimate)
• Vapor Pressure: 7.76E-13mmHg at 25°C
• Refractive Index: 1.4480 (estimate)
• Storage Temp.: Refrigerator
• Solubility: Acetonitrile (Slightly), Chloroform (Slightly), Methanol (Slightly)
• PKA: 14.68±0.70(Predicted)
• CAS DataBase Reference: 7-KETOCHOLESTEROL(CAS DataBase Reference)
• NIST Chemistry Reference: 7-KETOCHOLESTEROL(566-28-9)
• EPA Substance Registry System: 7-KETOCHOLESTEROL(566-28-9)

Safety Data

• WGK Germany: 3
• RTECS: FZ8708000
• Hazardous Substances Data: 566-28-9(Hazardous Substances Data)

Usage

Uses

1. Analytical Chemistry:
7-Keto Cholesterol is used as a standard in the determination of cholesterol derivatives by Gas Chromatography-Mass Spectrometry (GC-MS) and High-Performance Liquid Chromatography (HPLC). This application is crucial for accurate identification and quantification of cholesterol-related compounds in various samples.
2. Metabolite of Cholesterol:
As a metabolite of cholesterol, 7-Keto Cholesterol plays a role in the understanding of cholesterol metabolism and its implications in various physiological and pathological processes.
3. Medical Research:
7-Keto Cholesterol is used in medical research to study its effects on various chronic diseases, such as atherosclerosis, Alzheimer's disease, and age-related macular degeneration. Its increased levels in lipid deposits are associated with these conditions, making it a valuable research tool for understanding the underlying mechanisms and potential therapeutic targets.
4. Inflammation and Immune Response:
7-Keto Cholesterol is used to study its role in inducing activation and chemotaxis of retinal microglia, as well as polarization to a pro-inflammatory state via NLRP3 inflammasome activation in vitro. This application helps researchers understand the inflammatory processes associated with certain diseases and develop potential therapeutic strategies.
5. Ocular Research:
In ocular research, 7-Keto Cholesterol is used to study its effects on intraocular levels of VEGF, IL-1β, and GRO/KC, macrophage infiltration, and neovascularization in rat eyes. This application aids in understanding the role of 7-Keto Cholesterol in ocular diseases and the development of potential treatments.

Biochem/physiol Actions

7-ketocholesterol is a strong inhibitor of cytochrome P450 7A1. It modulates cholesterol homeostasis, cytotoxicity and apoptosis. 7-ketocholesterol stimulates inflammation, growth inhibition and vascular endothelial growth factor. Cellular accumulation of 7-ketocholesterol enhances oxidative stress, endoplasmic reticulum stress and apoptosis in macrophages.

Safety Profile

Questionable carcinogen with experimental tumorigenic data. When heated to decomposition it emits acrid smoke and irritating fumes

InChI:InChI=1/C27H44O2/c1-17(2)7-6-8-18(3)21-9-10-22-25-23(12-14-27(21,22)5)26(4)13-11-20(28)15-19(26)16-24(25)29/h16-18,20-23,25,28H,6-15H2,1-5H3/t18?,20-,21+,22?,23?,25?,26-,27+/m0/s1

Upstream product

• 57-88-5 cholesterol 
• 36871-91-7 3β-hydroxycholest-5-ene-7α-hydroperoxide 
• 75-91-2 tert.-butylhydroperoxide 
• 55529-60-7 cholesterol 5α-hydroperoxide 
• 57-88-5 cholesterol 
• 57-88-5 cholesterol 

Downstream Products

• 16840-37-2 7-hydroxycholesterol 
• 566-27-8 cholest-5-en-3β,7β-diol 
• 6997-41-7 3β-benzoyloxy-cholest-5-en-7-one 
• 7591-17-5 3β-hydroxy-5α-cholestan-7-one 
• 567-72-6 cholest-3,5-dien-7-one 
• 55429-58-8 (3S,8S,9S,10R,13R,14S,17R)-17-((R)-1,5-Dimethyl-hexyl)-10,13-dimethyl-3-trimethylsilanyloxy-1,2,3,4,8,9,10,11,12,13,14,15,16,17-tetradecahydro-cyclopenta[a]phenanthren-7-one 
• 82033-65-6 2-Iodo-7-oxo-4-nor-2,3-secocholest-5-en-3-yl formate 
• 566-26-7 (3S,7S,8S,9S,10R,13R,14S,17R)-17-((R)-1,5-Dimethyl-hexyl)-10,13-dimethyl-2,3,4,7,8,9,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthrene-3,7-diol 
• 20978-24-9 3-keto-7α-hydroxycholestane 
• 13400-67-4 3,7-dioxo-5α-cholestane 
• 809-51-8 7-ketocholesteryl acetate 
• 25876-54-4 Δ⁴-7β-hydroxycholesterol 
• 40824-59-7 3β,7α-cholest-5-ene-3,7-diol-3-benzoate 
• 17974-80-0 3β,7β-cholest-5-ene-3,7-diol-3-benzoate 

Relevant articles and documents

Metal-Free Allylic Oxidation of Steroids Using TBAI/TBHP Organocatalytic Protocol

A mild, efficient and organocatalytic allylic oxidation of steroids using a TBAI/TBHP protocol has been developed. A range of bioactive Δ5-en-7-ones can be easily prepared from the corresponding Δ5-steroids. The methodology features several advantages, including readily available starting materials, environmentally benign oxidant, high functional group compatibility, and metal-free catalysis.

Cholesterol degradation in archaeological pottery mediated by fired clay and fatty acid pro-oxidants

Cholesterol is generally absent in animal fat residues preserved in archaeological ceramic vessels. It is known from edible oil refining that during bleaching with activated clay sterols are degraded, largely via oxidation. Laboratory heating experiments

Effect of Eleven Antioxidants in Inhibiting Thermal Oxidation of Cholesterol

Eleven antioxidants including nine phenolic compounds (rutin, quercetin, hesperidin, hesperetin, naringin, naringenin, chlorogenic acid, caffeic acid, ferulic acid), vitamin E (α-tocopherol), and butylated hydroxytoluene (BHT) were selected to investigate their inhibitory effects on thermal oxidation of cholesterol in air and lard. The results indicated that the unoxidized cholesterol decreased with heating time whilst cholesterol oxidation products (COPs) increased with heating time. The major COPs produced were 7α-hydroxycholesterol, 7β-hydroxycholesterol, 5,6β-epoxycholesterol, 5,6α-epoxycholesterol, and 7-ketocholesterol. When cholesterol was heated in air for an hour, rutin, quercetin, chlorogenic acid, and caffeic acid showed a strong inhibitory effect. When cholesterol was heated in lard, caffeic acid, quercetin, and chlorogenic acid demonstrated inhibitory action during the initial 0.5 h (p a high flame is recommended. If baking or deep fat frying food in oil, it is best to limit cooking time to within 0.5 h.

Cholesterol transformations during heat treatment

The aim of the study was to characterise products of cholesterol standard changes during thermal processing. Cholesterol was heated at 120 °C, 150 °C, 180 °C and 220 °C from 30 to 180 min. The highest losses of cholesterol content were found during thermal processing at 220 °C, whereas the highest content of cholesterol oxidation products was observed at temperature of 150 °C. The production of volatile compounds was stimulated by the increase of temperature. Treatment of cholesterol at higher temperatures i.e. 180 °C and 220 °C led to the formation of polymers and other products e.g. cholestadienes and fragmented cholesterol molecules. Further studies are required to identify the structure of cholesterol oligomers and to establish volatile compounds, which are markers of cholesterol transformations, mainly oxidation.

Cholesterol hydroperoxides generate singlet molecular oxygen [O 2(1Δg)]: Near-IR emission, 18O-labeled hydroperoxides, and mass spectrometry

In mammalian membranes, cholesterol is concentrated in lipid rafts. The generation of cholesterol hydroperoxides (ChOOHs) and their decomposition products induces various types of cell damage. The decomposition of some organic hydroperoxides into peroxyl

Synthesis of 7-hydroperoxycholesterol and its separation, identification, and quantification in cholesterol heated model systems

7-Hydroperoxycholesterol is considered to be an intermediate compound of the cholesterol oxidation path as the first product formed when cholesterol is oxidized by triplet oxygen. However, there is a limitation on cholesterol mechanism studies because of the lack of 7-hydroperoxycholesterol analytical standard due to its low stability. To verify the formation of hydroperoxides in cholesterol model systems heated at 140, 180, and 220 °C, 7α-hydroperoxycholesterol was synthesized by cholesterol photooxidation followed by rearrangement at room temperature in chloroform. Its structure was confirmed on the basis of 13C NMR and mass spectra obtained by APCI-LC-MS. The synthesized compound was also used as standard for the quantification of 7-hydroperoxycholesterol as the sum of 7α-and 7β-hydroperoxycholesterol. The results demonstrated that 7-hydroperoxycholesterol is the first compound formed when the temperature is lower (140 °C). However, the concentration of the 7-hydroperoxycholesterol depends on the temperature and time of exposure: the higher the time, the higher the amount of 7-hydroperoxycholesterol at lower temperatures, and the lower the time, the lower the amount of 7-hydroperoxycholesterol at higher temperatures (180 and 220 °C). By the formation of 7-hydroperoxycholesterol, the known cholesterol oxidation mechanism in three phases (initiation, propagation, and termination) could be confirmed; once at lower temperatures, the stage of cholesterol oxidation is at initiation, at which hydroperoxide formation predominates.

Allylic oxidations catalyzed by dirhodium caprolactamate via aqueous tert-butyl hydroperoxide: The role of the tert-butylperoxy radical

Dirhodium(II) caprolactamate exhibits optimal efficiency for the production of the tert-butylperoxy radical, which is a selective reagent for hydrogen atom abstraction. These oxidation reactions occur with aqueous tert-butyl hydroperoxide (TBHP) without rapid hydrolysis of the caprolactamate ligands on dirhodium. Allylic oxidations of enones yield the corresponding enedione in moderate to high yields, and applications include allylic oxidations of steroidal enones. Although methylene oxidation to a ketone is more effective, methyl oxidation to a carboxylic acid can also be achieved. The superior efficiency of dirhodium(II) caprolactamate as a catalyst for allylic oxidations by TBHP (mol % of catalyst, % conversion) is described in comparative studies with other metal catalysts that are also reported to be effective for allylic oxidations. That different catalysts produce essentially the same mixture of products with the same relative yields suggests that the catalyst is not involved in product-forming steps. Mechanistic implications arising from studies of allylic oxidation with enones provide new insights into factors that control product formation. A previously undisclosed disproportionation pathway, catalyzed by the tert-butoxy radical, of mixed peroxides for the formation of ketone products via allylic oxidation has been uncovered.

Allylic Oxidations Catalyzed by Dirhodium Catalysts under Aqueous Conditions

The present invention relates to compositions and methods for achieving the efficient allylic oxidation of organic molecules, especially olefins and steroids, under aqueous conditions. The invention concerns the use of dirhodium (II,II) “paddlewheel complexes, and in particular, dirhodium carboximate and tert-butyl hydroperoxide as catalysts for the reaction. The use of aqueous conditions is particularly advantageous in the allylic oxidation of 7-keto steroids, which could not be effectively oxidized using anhydrous methods, and in extending allylic oxidation to enamides and enol ethers.

A comparison of the potential unfavorable effects of oxycholesterol and oxyphytosterol in mice: Different effects, on cerebral 24S-hydroxychoelsterol and serum triacylglycerols levels

Sterol oxidation products derived from cholesterol and phytosterol are formed during the processing and storage of foods. The objective of the present study was to assess the potential unfavorable effects of oxysterols in mice. C57BL/6J mice were fed an AIN-93G-based diet containing 0.2 g/kg of oxycholesterol or oxyphytosterol for 4 weeks. The most abundant oxysterol in the diet was 7-ketosterol, but α-epoxycholesterol, β-epoxycholesterol, or 7α-hydroxyphytosterol, and 7β-hydroxyphytosterol were more prominent than 7-ketosterol in the serum and liver respectively. Consumption of both oxysterols resulted in an increased in 4β-hydroxycholesterol and total oxycholesterol in the liver, but the oxycholesterol-fed mice had a lower level of cerebral 24S-hydroxycholesterol and a higher level of the serum triacylglycerols than the control and oxyphytosterol groups. These results indicate that both oxysterols in the diet are accumulated in the body, but that the biological effect of oxycholesterol is different from that of oxyphytosterol.

Process for oxidation of steroidal compounds having allylic groups

The instant invention involves a process for oxidizing compounds containing an allylic group, i.e. those containing an allylic hydrogen or allylic alcohol group, to the corresponding enones, using a ruthenium-based catalyst in the presence of a hydroperoxide. Particularly, Δ-5-steroidal alkenes can be oxidized to the corresponding Δ-5-7-keto alkenes.