Cholesterol cholest

Cholesterol. Cholest-5-en-3li-ol cholesterin. Cv-HwO mol wt 386.64. C 83.87%. H 11.99%, O 4.14%. Prin-cipal sterol of the higher animals. Found in all body tissues, esp in the brain, spinal cord, and in animal fats or oils. 

Cholesterol (cholest-5-en-3a-ol) is a A -steroid or, more specifically, a A -sterol, because it is an unsaturated... 

FIGURE 3.6 Steroids, (a) The carbon numbering system for steroids using cholesterol (cholest-5-en-3 3-ol) as an example. The individual rings of the carbon skeleton are labeled A to D. (b) Representations of the chair and boat conformations for a six-membered carbon ring illustrating equatorial (He) and axial (Ha) hydrogen atoms. 

Almost a decade after the X-ray crystal structure was determined, it was reported that, as part of more extensive work on the degradation of cholesterol, cholest-A en-3P-ol underwent ozonolysis to cleave the double bond and that pyrolysis of the ozonolysis product gave an unsaturated aldehyde. The work on cholesterol and the ozonolysis experiment are shown in Schemes 13.26 and 13.27. Scheme 13.27 also shows the relationship between the chiral aldehyde isolated on pyrolysis of the ozonolysis product from cholest-A en-3P-ol and optically active natural (/ )-(-E)-dfronellal. 

Regulatory FDA21CFR 107.10,166.110,184.1950, GRAS Japan approved BP, EP compliance Canada DSL Choleic acid Cholerebic. See Desoxycholic acid 5,7-Cholestadien-3- J-ol. See Cholecalciferol Cholest-5-en-3p-ol 5-Cholesten-3-P-ol. See Cholesterol Cholest-5-en-3-ol, octadecanoate. See Cholesteryl stearate 5-Cholesten-3p-ol 3-oleate. See Cholesteryl oleate Cholesteric esters Cholesterin. See Cholesterol Cholesterol... 

Addition of fluorine to 3-chloro- and 3-acetoxycholest-5-ene likewise furnishes crystalline difluorides. The product derived from cholesterol acetate in 10-20% yield is identical with the 5a,6a-difluoride (3) prepared by Barnes and Djerassi by the PbF procedure (see below). Fluorination of cholest-5-en-3-one does not proceed satisfactorily. 

Cholesterol Cholesterolester-hydrolase + Chol-esteroloxidase (double reaction) Cholest-4-en-3-one, h2o2 Na2HP04 NaH2P04 pH 6.8 Iodide 50-400 mg %... 

The oxidation of cholesterol to cholest-4-ene-3-one is carried ont by an oxidase in several bacteria. This activity has been fonnd in Brevibacterium sterolicum and Streptomyces sp. strain SA-COO (Ohta et al. 1991), and the extracellnlar enzyme that has been purified from Pseudomonas sp. strain ST-200 (Donkyn and Aono 1998) has a preference for 3p-hydroxy componnds. 

Figure 15.6 (a) Negative ion ToF SIMS spectrum of greasy Spanish wool. Idomologous series of ions (, I) n alkanoic acids and iso alkanoic acids, ( ) anteisoalkanoic acids, ( ) hydro xyalkanoic acids and (A) 18 methyleicosanoic acid thioester derivative ion. (b) Positive ion ToF SIMS spectrum of greasy Spanish wool (m) cholesterol and (A) cholest 5 en 3 ol one ions. Reproduced from Applied Surface Science, Batcheller et ah, Copyright 2006 with permission from Elsevier... 

As mentioned earlier, oxidation of LDL is initiated by free radical attack at the diallylic positions of unsaturated fatty acids. For example, copper- or endothelial cell-initiated LDL oxidation resulted in a large formation of monohydroxy derivatives of linoleic and arachi-donic acids at the early stage of the reaction [175], During the reaction, the amount of these products is diminished, and monohydroxy derivatives of oleic acid appeared. Thus, monohydroxy derivatives of unsaturated acids are the major products of the oxidation of human LDL. Breuer et al. [176] measured cholesterol oxidation products (oxysterols) formed during copper- or soybean lipoxygenase-initiated LDL oxidation. They identified chlolcst-5-cnc-3(3, 4a-diol, cholest-5-ene-3(3, 4(3-diol, and cholestane-3 3, 5a, 6a-triol, which are present in human atherosclerotic plaques. 

The isomerization reaction is also encountered in chemical manipulations of steroids. Thus, many natural steroids contain a 5-en-3-ol combination of functionalities, e.g. cholesterol. Treatment of cholesterol with an oxidizing agent (aluminium isopropoxide is particularly suitable) leads to cholest -en-3-one, the tautomerism occurring spontaneously under the reaction conditions. 

Ezetimibe/Simvastatin (Vytorin) [Antilipemic/HMG CoA Reductose Inhibitor] Uses H rp cholest olemia Action X Absorption of cholesterol phytost ol w/ HMG-CoA reductase inhibitor Dose 10/10-10/80 mg/d PO w/ cyclosporine or danazol 10/10 mg/d max w/ amio-darone or verapamil 10/20 mg/d max -1- w/ sev e renal insuff Caution [X, -] w/ CYP3A4 inhibitors (Table VI-8), gemfibrozil, niacin >lg/d, danazol, amiodarone, verapamil Contra PRG/lactation livCT Dz, t LFTs Disp Tabs SE HA, GI upset, myalgia, myopathy (muscle pain, weakness, or tendOTiess w/ CK 10 x ULN, rhab-domyolysis), Hep, Infxn Interactions t Risk of myopathy W7 clarithromycin, erythromycin, itraconazole, ketoconazole EMS None OD Sxs unknown symptomatic and supportive... 

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