Cholesterol structural formula

Therapeutic Function Solubilizer for cholesterol gallstones Chemical Name 3,7-Dihydroxycholan-24-oic acid Common Name Chenodeoxycholic acid chenic acid Structural Formula ... 

Structural formula and line drawing of caffeine, and line drawing of cholesterol. 

SAMPLE SOLUTION (a) As the structural formula in step 5 of Figure 26.10 indicates, the double bond of cholesterol unites C-5 and C-6 (steroid numbering). The corresponding carbons in the cyclization reaction of step 1 in the figure may be identified as C-7 and C-8 of squalene 2,3-epoxide (systematic IUPAC numbering). 

It is natural to classify lipids as polar or non-polar according to their interaction with water. Non-polar lipids, for example triglyceride oils, do not form aqueous phases, whereas polar lipids do. Except for cholesterol, membrane-forming lipids form aqueous phases and have polar head groups. Within membranes there are also trace amounts of lipids in membranes that do not interact with water, for example diacylglycerols. The structural formulae of two common membrane lipids, phosphatidylcholine (PC) and phosphatidylethanolamine (PE) are shown above. 

Wieland) and the 1928 (Windhaus) Nobel Prizes in chemistry. All that remained was the determination of the structural formula for cholesterol and the first synthesis of the compound, both achieved by the American chemist Robert Burns Woodward (1917-1979) in 1955. 

Figure 19.10 shows a structural formula for cholic acid, a constituent of human bile. The molecule is shown as an anion, because it would be ionized in bile and intestinal fluids. Bile acids, or, more properly, bile salts, are synthesized in the liver, stored in the gallbladder, and secreted into the intestine, where their function is to emulsify dietary fats and thereby aid in their absorption and digestion. Furthermore, bile salts are the end products of the metabolism of cholesterol and, thus, are a principal pathway for the elimination of that substance from the body. A characteristic structural feature of bile salts is a cis fusion of rings A/B. 

Draw the structural formula for the product formed by treating cholesterol (a) with H2/Pd (b) with Br2-... 

Both low-density lipoproteins (LDL) and high-density lipoproteins (HDL) consist of a core of triacylglycer-ols and cholesterol esters surrounded by a single phospholipid layer. Draw the structural formula of cholesteryl linoleate, one of the cholesterol esters found in this core. 

Sterols are present in all plant and animal tissues. The chief animal sterol is cholesterol, C27H46O, with structural formula... 

Following is the structural formula and a ball-and-stick model of cholestanol.The only difference between this compound and cholesterol (Section 26.4) is that cholesterol has a carbon-carbon double bond in ring B. 

Following is the structural formula of mevalonic acid, a key intermediate in the biosynthesis of cholesterol. Write the lUPAC name of this compound. 

Figure 8.4 The structure of cholesterol, (a) Formula (b) molecular outline...

Sterols (from the Greek (rr pe6s meaning solid) are complex solid alcohols found in the unsaponifiable lipid fraction from the tissues of most animals and many plants. The principal, but by no means the only sterol of the vertebrates, is cholesterol, the structural formula of which, together with the conventional numbering system, is shown... 

From the structural formula of cholesterol shown on page 1006, determine (a) the composition, and (b) the number of... 

A structural formula for cholesterol is shown below. How many chiral carbon atoms are there in the cholesterol molecule What is the configuration, R or S, of the carbon atom bonded to the —OH group What is the configuration, E or Z, of the double bond ... 

The structure of cholesterol is given in the text (See Figure A, p. 603) What is its molecular formula ... 

FIGURE 1.11. The derivation of the chemical formulae of steroids resulting from Bernal s X-ray crystallographic work. I and II had been put forward as possible fcrmulae, but III seemed to provide a better fit to the experimental data on molecular ine from refractive index data combined with unit cell dimensions. Bernal listed ses 8.5 x7.0 xl8 A for I, 11.0 x7.5 xl5 A for II, 7.5 x4.5 x20 A for III (from models built to scale), and 7.2 x5.0 x 17-20 A from observed data from X-f .y studies and refractive index measiu-ements. The correct formula, which is very iiiniiar to formula III, is shown in formula IV (cholesterol). The crystal structure of cholesteryl iodide is shown as V. (The value of the parameter x reported for C15 apparently should be 0.585, not that reported in ref. 85.) Iodine atom, filled circle. 

FIGURE 15.18. The structure of cholesterol myristate (Ref. 144). Some unit-cell edges are indicated, (a) Chemical formula, and (b) and (c) two views of the molecular packing in the crystal, (b) View onto the steroid ring systems, and (c) view along them. The equilibria, with temperatures, are ... 

In the past, determining the structure of a new compound was a major hurdle to overcome. It is sometimes hard for present-day chemists to appreciate how difficult structure determinations were before the days of NMR and IR spectroscopy. A novel structure which may now take a week s work to determine would have provided two or three decades of work in the past. For example, the microanalysis of cholesterol was carried out in 1888 to get its molecular formula, but its chemical structure was not fully established until an X-ray crystallographic study was carried out in 1932. 

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